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MG Midget and Sprite Technical Midget MX5 5 speed conversion BBS discussion at MG-Cars.info
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MG Midget and Sprite Technical - Midget MX5 5 speed conversion
| Hi All,
I am a new member having recently purchased a 1971 1275 midget Mk3. My first sportscar was a 1500 midget c.1980, loved it but underpowered after a Mini Cooper (sadly no longer mine) Test drove a TR6, WOW... bought it & still run it 38 years on! Having restored my son's MGB GT for his wedding a few years back I have now succumbed to another midget, great fun, my daughter loves it. However the clutch has just been contaminated by oil from the gearbox after parking on a steep hill and needs to come out. Having driven the car from Birmingham to Cornwall I had already come to the conclusion that another gear would be good. Having now read many hours of articles on Ford T9 and Datsun B210 and Starlet gbox conversions but finding all of these to be rare/pricey I have aquired a low cost MX5 gearbox to investigate the possibilities. Ratios look to be reasonable & I reasonable have access to facilties. Having measured it up I think it should fit quite readily needing the gearchange shortening and probaby the tunnel slightly modified.I plan to use an MX5 prop mated to midget diff flange. I have not yet got the engine out to determine how to mate the two lumps together. Anyhow, I can't find any info on doing this so am I the first, surely not? If anyone has any experience or advice then it would be greatfully received, if not then I will let you know how I get on if anyone is interested as it should be quite low cost, box from £20, prop fron £10, new centreplate most cost at £60 odd or s/h if available plus making an adapter plate. It will be a bit of a winter project however. Sorry if too long-winded, thanks everyone, JohnMac |
| j c macleod |
| Not heard of anyone doing it on a Midget but Vitesse do a conversion for the MGA and B so they may be of some help. Trev |
| T Mason |
| Welcome John. Interesting idea. I have an dim recollection I read about it once on an American site maybe, where they're called Miatas I think. I'll certainly be interested to follow your project. Is the car another 1500 or an A series? |
| Greybeard |
| John
Very interesting. As Trev says above, Vitesse is using the MX5 gearbox for the MGA and MGB. I was at the Classic Car show the other day and spent some time at the Vitesse stand looking at it. See https://www.vitesse-ltd.com/products/mga-5-speed-mazda-gearbox-conversion-kit I really like the idea of a 5 speed box for my MGA, but the price is difficult to justify bearing in mind I only do maybe 1,000 miles a year. So I was thinking about the merits of using a reconditioned box. The work may well be beyond me, but I would be very interested to hear how you get on. |
| Graham V |
| Well it's got to be worth a try. Type 9's are expensive now and so is the kit to convert. Getting all the dimensions, clutch and clutch operation right is where it will be difficult. Cutting the car and mounting the box will be fairly easy I suppose.
Bill SDGPM on here tried it with a BMW box a few years ago and gave up in the end - just food for thought! One thing to consider is gear lever position, the Type 9 puts it too far back so it will be worth finding out that dimension first as you don't want it to be even worse than the Ford. Good luck and I'd definitely speak to Vittesse even if it's just for clutch ideas. |
| John Payne |
| I too saw Vitesse units on display at the NEC and I thought they looked very good - better than the commercial T9 outfit Spridget owners are normally stuck with. With gear lever position, the T9 can have a shortened remote so that the gear lever remains very close to the original position. |
| Nigel Atkins |
| Hi John
The MX5 box is a good choice of box, cheap and easy to find. Like you mention, you aren't the first to have this idea. For the life of me I can't remember why nobody does this conversion. It's always been about the type 9, which are now very dear. The type 9 has a removable bellhousing doesn't it, which means you can fit a custom one to put the box in the right position fore/aft, and also allow fitment of the starter motor in the desired place. The MX5 box has a fixed bellhousing am I right? So not sure if it is possible to get it in the right place allowing for the adaptor plate. And doesn't the starter live on the nearside on an MX5? Maybe it would foul on a Midget exhaust. There are not many boxes about suitable for kit cars, which is why the type 9 is the price it is. RX8 gearboxes are becoming popular so I read, 5 or 6 speeds and good reliability. But again I think they have a integral bellhousing. Hope this helps a bit! Cheers Matt |
| Tarquin |
| "RX8 gearboxes are becoming popular so I read, 5 or 6 speeds and good reliability. But again I think they have a integral bellhousing." So go the whole hog and fit the 1.3 litre rotary engine along with the 6 speed gearbox? ...and 230bhp :) |
| Jeremy MkIII |
| Thankyou all,
I have been busy looking into this and I think it is "do-able". I have already obtained a MK1(? TBC) box of unknown mieage (poss 100k)for £21 pounds locally through ebay so too good to miss even if just for measuring up. I have since compared it to my Mk3 midget and I think it will fit with only limited metal work to the shell. I may need to lose about 2" from the entrance to the tunnel by cutting out the centre section of the gearbox crossmenber but can simply close up the ends of the cross member by capping them and simultaneously create new pickup points for the MX5 rear support, for which I can fabricate a fairly heavy (5/6mm thick) bracket of only about 3-4 inches length to pick up the rear mounting bolt holes with a rubber mount from somewhere. This clearance is necessary to give the "belly" of the box some room as it is longer in the body than the MG box but surprisingly only about 1 inch overall. The starter motor is in the correct place as is the clutch release arm. However after visiting the Vitesse site (thankyou Trev)I see that a concentric slave cyclinder can be had from ebay for £39 new so tempted to investigate that route (any comments on CSC as no experience knowingly). My biggest unkown is the flywheel. The MX5 1.6l centreplate is 200mm (8") diameter whereas the 1275 midget plate is 7.5" so will it fit without too much trouble. If it will fit inside the MG pressure plate then should be OK, else maybe I can fit a MX5 pressure plate to the flywheel. (I have friendly machine shop facilties available) The bell housing dimensions seem to be quite similar so I think the MG flywheel will fit in. Nad I think an adaptor plate can be created or the MG rear plate modified. I dont know about "insertion depth" yet. The MX5 input shaft stops about 20mm short of the bellhousing face(yet to be measured accurately). I am hoping that this is not the sticking point. If to short then I can lose a it from the bellhousing, if too long then a thicker adaptor plate or spacers. Amazing you can purchase complete pressure plate, centre plate and release bearing kit for an MX5 232, etc new for £40 inc vat! Ok may not be a high power unit but more than a stock 1275 surely. Competition kits go up to £350 if necessary. The gearstick mechanism protrudes rearwards in a tube and is secured by 4 bolts via a steel bracket, so surely can readily be modified (unlike the later MK3 and 6 speed boxes which is all cast aluminimum so less attractive) I think I can cut the tube to move the gearstick hub forward and create a "reversed" bracket to secure it to at least 2 of the original bolt holes. I beleive that this will put the gearstick no more than 1 inch further back but it may be possible to reduce this by modifying the assembly a bit more. I guess you could move the whole engine assembly forward a bit at some possible detrement to handling (any comments?)This may also alleviate any clearance problems with the battery tray area which as yet I cannot tell. The tunnel may need to be "swelled" a little but not much. The propshaft will only be about an inch shorter. The Mk1 & 2 MX gearboxes all seem to have a large mounting cast into the drivers(UK)side, I assume for mounting in the MX5 (obvs) but this can easily be removed to create more room in the tunnel. I plan to use an MX5 prop to get the output spline & UJ, shortening as required and either hybrid crossing the diff UJ between MX5 and MG or could cut and weld the 2 props at the diff end together. Subject to the adaptor plate cost I think this could be done sub £300! Anyhow, hopefully this makes sense. Comments , help and encouragement gratefully received, and will post some pics when there is something to see. One final point I was momentary tempted by mazda engine but I need to keep the 1275 for tax exempt, mot exempt and young daugthers' insurance reasons. I see in DVLA that you can make some changes if they improve efficiency e.g. modern gearbox, so... cheers for now, John |
| j c macleod |
| I think the 1275 clutch plate is only 6.5”. |
| Dave O'Neill 2 |
| John
Sounds like a good idea to me-- That lump on the r/h side of the Mx box is used for a steel bracket that bolts onto the g/box and the diff to keep them all lined up and it acts as the rear gearbox support as they have no actual normal g/box mounting If you are going to mount it normally you can dispose of that bit "I think" the early Mazda FWD 323 had a clutch same spline and just over 7", maybe that might just squeeze into the MG pressure plate or get your machinist mate to set it up and grind it down till it fits, it shouldn't take much to get it in there--Don't know what od the little Mazda 808rwd's were they might be worth checking out- I like the use of the word "swelled"--A little swelling can make a big difference With that little X member up the front of the tunnel, if you have to cut that out, I'd weld/bolt another on underneath it, I cut mine out and I'm sure the car felt softer but after welding another accross under it again I'm sure it felt stiffer in the body With the tailshaft, just check the bolt pattern of the rear flange against the flange of the MG one, a lot of tailshafts run a universal flange pattern, you might just get away with a simple shortening of the Mazda shaft With the protrusion length of the front shaft-If it's too short by a little bit, instead of having to buzz a bit off the bellhousing a custom made stepped out spigot bearing might do the job Good luck willy |
| William Revit |
| Will certainly be interesting to see how you get on. I suspect the reason more people don't do it is that after investigating the effort they find it's just easier to buy an MX5 :-) Also, and don't take this personally as I don't know your circumstances at all, but for a young driver with the MX5 you get ABS, airbags, crumple zones etc. Classic sports cars are good fun but they are were hazardous in period and remain so today. |
| AdrianR |
| John,
I was talking to the gentleman on the Vitesse stand about concentric slave cylinders as mine has filled the master cylinder reservoir with black fluid and fibrous material after only about a 1,000 miles of use. He told me he'd not had this problem but he thought the csc might be the same regardless of whether they came in a Ford or First Line box. There's loads of info (and photos) of csc in the Achive (relating to T9). As Mazda and Ford had a close relationship at one time IIRC (and I may not) the Mazda box has something Ford about it(?). Having said that I saw the reverse gear was in a different place on the gear lever knob marking. I know for certain that the Mazda 6 speed box had some trouble at one time as I heard all about it when I recommended a MX-5 to a friend (but I never suggested a 6 speed), I had a new Mk2 in 1999/2000 when the 6 speed first came out in the anniversary model. |
| Nigel Atkins |
| Adrian, That's largely the reason the IOW Frogeye shut down, for the money one cost you could buy a new MX5 with lots more bits. I was present at a small part of the discussion with Keith Brading regarding ways to make it cheaper but it wasn't doable IIRC. |
| David Billington |
| Thankyou guys, your input is all very useful.
WIlliam: I had wondered about the 232 centreplate so will now investigate that line further. Also was having the same idea about a stepped out spigot bearing. I am thinking that you could machine machine a "top-hat" which could be fixed by the crankshaft bolts to simply extend the crankshaft to meet the gbox input shaft as you say. I cant think that the actual sideforces exerted on the spigot bearing are massive, being axial rotary forces instead. More concerned about keeping the the flywheel on the crank but it's not like I am working with a 300hp V8 here. I was concerned that the shorter MX input shaft may not reach far enough to get the centreplate up to the flywheel but I have been measuring the distances from outside and I think this is not a problem. Good point re the prop flange as could well turn it and re-drill. I was thinking to cut the middle 100mm or so out of the crossmember, then weld caps onto the ends after either inserting tapped plates and/or some spacer tubes to allow me bolt a new crossmember fabricated from 6/8mm steel across the gap which would double as a bracket to pick up the bck of the gearbox. There are two 8mm(?) tapped holes at the rear of the box waiting to be used, I will incorporate a suitable rubber mount somewhere. Thanks for the info regarding the MX tie bar. Adrian: None taken. The safety issues are certainly not to be taken lightly. This all started by me looking on ebay for a new hornpush for my 1972 TR! In the side bar popped a TR7 convertible project car which got me thinking, my younger daughter had shown interest in them at the club but then wasn't sure...what others are there Dad? Well the Spitfire or Midget would be classic British cars... "I love the midget with chrome bumpers!!!" A quick ebay later and this little midget seemed too good to miss. One expensive hornpush. Nigel: Interesting information. Do you have an MGB with Vitess conversion? If so, how do you like the concentric clutch feel/operation. Re the black fluid/material, my TR6 clutch master cyclinder always seems to go black quite soon after bleeding. I assume that my somewhat oily engine underside get into the slave past the rubber boot then get "pumped" past the piston seal as it goes back and forth. Your fibrous material must be from the centreplate surely. I once had a Rover 820 which had a brand new quality Borg&Beck(?)clutch fitted but very quickly failed, going sticky so that the clutch would not release, continuing to drive when the pedal was fully depressed. It turned out to be faulty plate manufacture, not properly cured, for which they paid for replacement. So shows that new failures do occur. regards to all, John |
| j c macleod |
| John, the forces on the spigot bearing aren't just axial and rotary, it has to resist side forces resulting from the input and layshaft gears wanting to separate due to the forces from the torque they transmit, at least the spigot bearing has a good lever advantage due to the input shaft length compared to the input gear distance from the bearing. |
| David Billington |
| Hi All,
back again. I have been thinking about the speedo. the MX5 uses an electronic speedo sensor, probably a pulse I presume. However the sensor is missing from my box and fetch they £30+ on ebay so I assume they fail. My background is in instrumentation and control with some electronic history. More control system design & PLC (programmable logic controller) programmng these days. Therefore I am thinking I might use an inductive proximity sensor (<£5 on ebay or £25 from RS etc) picking up the bolts in the diff flange, then feed the pulse into a micro controller (Arduino or PIC) to produce an output to drive either a small DC motor or preferably a stepper motor to drive the speedo drive. Could then be calibrated against satnav using the laptop or even incorporating an adjustment potentiometer or switch. This would save any recalibration issues and keep the dash original. Alternatively you could use an old MG electronic tacho inerds in the speedo to accept the pulse output from the Arduino but I suspect they are no longer easy to obtain. This system could work for any car project so could be of much wider interest. anyhow.. cheers for now, John |
| j c macleod |
| Hi David, yes I get your point. I need to get the engine & box out to really find out how to proceed. Unfortunately already got commitments this weekend so unlikely to get there:( John |
| j c macleod |
| I've got a Smiths Classic Speedo that works like that. Use 2 propshaft/diff bolts; keep the balance. If you use 4, the signal is odd because they are not evenly spaced. |
| Rob Armstrong |
| Hi rob,
amazing, I have never seen one like that. Get your point regarding the bolts. I would think I might be able to average that out in the code. It would actually help to fix a castelated ring around the flange to give several more counts, a la ABS sensors, which helps the measurement system since it is only doing what... 5000rpm X 1:1 3.9:1=1282 RPM = 21.3/sec which is not terribly fast in electonic terms. If the pulses are too slow you need to integrate over a longer period which could make the speedo response a bit sluggish, though I have done this succesfully on laboratory machines. Cheers, John |
| j c macleod |
| Hi John,
I had a "rubber-bumper" RV8 engine'd MGB roadster a couple of decades back but that had the LT77 gearbox. This summer on my Midget I had to have (yet another) clutch fitted so went for concentric slave this time. I don't know how or if you can tell the difference between external slave, concentric or even cable on the pedal and as I've gone from hybrid-Spridget clutch to Pinto clutch I don't know how much that adds to the feel - but this clutch set up is slightly heavier feel and push to the previous (three) clutch set ups I've had on this Midget in the last 8 years. Off board I can tell you who to avoid in classic land, others will be sick of hearing it on here again from me, as I am. Even with the fibrous material in my m/c I was thinking it was perhaps from rubbish-rubber as it has (does still?) invade many of the parts we get - but I could be wrong as I didn't feel the stuff just siphoned it out (baster) and clean with toothbrush which transferred it to an old, worn out, sock, which just happened to be black. If by old electronic tacho you mean a standard Spridget one then they'd be easy to obtain either new, s/h, broken or not working. Apart from the MGB a Spridget is probably one of the easiest cars to get parts for, including most more modern cars. David Smith and possibly Dave O'Neill on here alone have parts available - and Chris (at Octarine Services) is clearing out parts if you look at his thread in Midget and Sprite General. That's without all the new parts (of various quality) from the usual suppliers big and small. Pity you're so far from me otherwise we could swap run outs in TR6 and T9 Midget. I always fancied a TR6 but had a disastrous misadventure with a GT6 instead (Mk3 1973). If you'd been at the NEC I could have taken you and your daughter for run outs - and possibly dissuaded one or both of you from such a project. :) (Nov show 2017) - https://youtu.be/QTGuoNmiDRU |
| Nigel Atkins |
| John,
I'll be interested to follow your progress as I fitted a Ford 4 speed Escort box to my frogeye back in the mid 1980s and that was for reliability as I hadn't found the A series gearboxes I had to be durable even when rebuilt. It involved a new backplate to suit the Ford bellhousing pattern as an integral bellhousing unfortunately, the early mk1 Escort plate fitted the 1275 clutch cover and the gearbox crossmember needed slight mods although I think they could have been avoided with different engineering. The sump was modified to clear the starter and a slight notch in the chassis rail to clear the starter also. Worked very well and was reliable and synchro on 1st was a benefit when hillclimbing. |
| David Billington |
| Thanks Nigel. If you ever get down to Cornwall (as everybody seems to!) we can make a TR6 drive happen anyway. Mine is an early mildly tuned 150HP with 3 speed overdive, close ratio box and longer diff ratio. Reckoned to be the best option which was built for only a few months at end of '72. Bought by shear luck 38 years ago. It's not perfect by any means but it often surprises the non-initated. John. |
| j c macleod |
| Hi John,
I am amazed/delighted at the interest in my thread. I am determined to give this my best shot so having others interested is a great spur to my enthusiam. Interesting regarding your notes on the Ford box. The layout of the MX5 box appears very good with the starter on the correct side. Been out measuring up tonight and still quite confident it is do-able. The flywheel will be the most "interesting" part :) I have never been afraid to give things a try, though not always with the anticipated success! But rarely beaten. John |
| j c macleod |
| John
Not sure if you are aware of these-- By the time you go get an electronic speedo and the pickup and set it all up, maybe you would be better off with a gps speedo If going down the semi purist route you can get a smiths style replica but probably 300 pounds but there are less expensive non replica ones from places like Autometer A mate here has one in his drag boat and it reads exactly the same as the timing gear on the shore--no sensors or anything, everything including the gps is built into the speedo Another fella I know bought one off ebay from china for $100 for his m/bike, it took about three weeks to arrive but it was free shipping so didn't matter and it also works faultlessly just a thought willy |
| William Revit |
| A thought on the clutch. I've got the Datsun 210 gearbox using the Datsun clutch with my 1275. I just measured the pressure plate and the overall diameter is 9.5 inches with the disc measuring 7 inches. If you can find a Mazda clutch that mates to the input shaft that you have (as per Willy's suggestion) and is smaller than the 1275 flywheel, you can have the flywheel drilled and tapped to accept the Mazda clutch. Easier then trying to match a disc to a pressure plate. |
| Martin |
| John,
I like the sound of your TR6 unfortunately I've already sneaked into Cornwall three times I can't see I'd be allowed in again. First time was with a (factory-built) Westie, second I forget which car but third was with the GT6. A friend had at the time a share in the family's house in Port Isaac and as we were leaving the village. He pulled up on the very steep road when leaving the village in his fully functioning Japanese car (Supra) leaving me sweating and swearing at him as I pulled up the GT6 handbrake lever with both hands whilst pressing the brake pedal with all my might as I felt the car starting to slip back towards the front grille of our other friends's very new Jag 2nd-gen XK. I get my own back on him by saying how much Doom Bar (Bitter) has improved since the Americans took it over. :) |
| Nigel Atkins |
| This sounds like a great idea, yes I have thought about it but these days I am finding it hard to enthuse about getting out my leaking type 9 again
My BMW Project stalled because I had the gearbox stolen off my drive by wandering wastrels, I was well on the way I'd done the new backplate (Plasmacut steel one) and had the output flange remade to suit the BMW drive flange I was going to fit the Beemer's speedo sensor and drive the unit from the donor car adapted to sit inside the Midget's housing That would have entailed arranging a 'cutter vane' to be read by the magnus inside it From what you are saying this is a very do-able plan I am watching closely |
| Bill sdgpM |
| Hi John
I too will watch with interest! Anything is doable with time and brains, money is not always needed in large amounts. I always enjoy listening to experts when they talk tech talk, feel free to give us more electrical control chat! Geek city round here sometimes, can't beat it. I have acquired a K series midget which uses the original triumph box, I would like to fit a modern 5 speeder but type 9's to take good power are far too expensive. The MX5 box sounds good, wonder if it will fit to a K series?! On the clutch front, I use a little firm up here called ACS in earlsheaton that can make any clutch plate you like, so if you need something making up I would be happy to investigate for you. Cheers Matt |
| Tarquin |
| John
The more I think about this project the more I get interested Having done the odd engine swap or two, I would like to suggest, keep it simple and use as many std. parts as possible, keeping later maintenance/replacement in mind- Having said that, to me, the best most simple way to go is use all Mazda MX5 clutch and pressure plate 'if possible to get it on the Midget flywheel Also I'd stick to the external slave cylinder and clutch fork etc for a couple of reasons, one being easy to get at and replace if needed and also price and you know it will work Unfortunately the Midget f/wheel has a step on the outside reducing it's diameter just where you need it to be larger But, I notice that most of the aftermarket alloy flywheels for Midgets are flat and full diameter in the area where it would need redrilling for the Mazda p/plate Oh yeah, if you go to get a Mazda clutch assy be aware there are two types, one for a flat flywheel which is the one for you but there is another that holds the p/plate up on pedestals built into the flywheel which would be useless to you I have various dead Mazda parts laying about if you need some measurements, shame you're on the other side of the world, I have a spare early flat miata flywheel sitting in the garden you could have had for free to play with --Maybe a Mazda flywheel could be fitted to the Midget crank and machined to take a Midget ringgear----The miata flywheel has the spigot bearing pressed into the centre hole of the flywheel----------The guy you got your gearbox off might have one to play with--or I'm happy to measure this one up or photos or whatever willy |
| William Revit |
| Hi All,
this really is taking on a life of it own, great! I would really like to just stop what I am doing with my work( a self-employed controlS engineer) and get stuck in but unfortunately I don't think that would go down too well with my long-suffering wife. However, I have just this evening have been very fortunate. Whilst following up on a replacement bonnet for the rather tatty one I have from a contact in my church, I have been able to borrow an empty midget gbox case, sandwich plate, 1275 flywheel, centreplate & pressure plate as well as measure the crankshaft tail length to determine the flywheel position in the bellhousing. This has enabled me to make a cardboard template to transfer the centreline onto the MX bellhousing and determine the relationship to the splines and bellhousing. The good news is that I am reassured that this can be done, albeit not without plenty of tea drinking. Thanks Willy for your latest input. The two big issues are indeed that the MX5/Miata centreplate is 200mm or 215mm diameter according to the web and we only have about 6mm clearance between the MG centre plate (168mm diam.) and the MG pressure plate i.e. 168+12= 180mm with little margin for error. The 323 plates I see on the net appear to 20 spline whereas the MX5 is 22 spline.(I appreciate there do seem to be some variations which may be worth looking into and even the Ford Fiesta plate possibly since Ford & Mazda have history). As you say it may be possible to attach the MX pressure plate, certainly a cheap parts option and answers various issues. The next issue is actually "reaching the splines". I measure the face of the midget flywheel being 48.3mm from the rear face of the sandwich plate, i.e. the face of the gbox. The splines of the MX box begin at 35mm (?TBC) from the gbox face so providing only partial engagement of the centreplate splaines onto the input shaft, this is however only with refernce to the midget centreplate as I do not yet have a Mazda plate. Actually Willy if you have an MX5/Miata centreplate please could you measure 1. the centreplate boss length, 2. the boss offset from the flywheel side, 3. the centreplate working thickness, and if you have a presuure plate any dimensions of that would be handy. Cheers. Thanks Matt for your input, it may well be that the above spline engagement issue could be overcome by your people ACS to build a plate with extended boss to "reach" the splines. If using the MG pressure plate with carbon thrust bearing then the clearance to the input shaft nose tube is limited and the tube will need to be reduced. This does lend to a concentric slave cylinder which can then bolt onto the gbox front bearing cover. This would probably be easier to accommodate than the external slave and lever but I do hear what you are saying Willy and will look closely at the relative merits here. The CSC is available on ebay for a Mazda fitment for only £40 over here and there is a good looking Alfa Romeo fitment for less than that, so cost is not the issue, more having to remove the engine if it fails. Regarding the MG flywheel (9-3/4" O.D. = 248mm), yes there is a step (2.65mm deep) but at 213mm dia. outside the MX5 centreplate diameter of 200mm. I wonder if one can somehow accomodate the step with a simple machined "washer" to allow the MG flywheel to be drilled for the MX5 pressure plate and all bolted up solid onto the washer. I can also investigate the MX5 flywheel since it is a bit "swings & roundabouts" though then it would probably be easier to use an MX5 starter since I will be making a new sandwich plate so can acommodate as required. Regarding the starter, the MX5 starter is on the drivers(UK) side but above centreline instead of below. This means retaining the original starter position will probably require taking a sharkbite out of the MX5 bellhousing to give it room but since it is bolted to an 8mm steel plate I dont think losing the bellhousing support will matter greatly nor compromise the bellhousing rigidity to much either. I would likely fabricate a steel "patch" to drill and tap to bellousing over the bite hole to keep muck out and perhaps replace some rigidity. I need to look in the engine bay to see if there is room for a starter motor higher up. Matt, If this game is successful in the tunnel installation, etc. then I will happily pass on any dimensions & useful templates to see how it would look on a K series. Finally (at 1:40am!) I have a bit of a dodgy shoulder ATM so am contemplating making a plywood buck of the MX5 gbox, pieces cross-slotted together like the old car mock-ups, to use to locate in the tunnel to make room/position the gstick, etc. unless my son can find time to assist with lifting when I get there. I will see if this is just a time waster but I do have a good friend who I helped get a full sheet CNC router working who could cut it out in minutes if I can give hime the shapes in CAD. I hope I am still making sense and will try to keep the momentum going, regards to all, John |
| j c macleod |
| Might have read this wrong, but if the flywheel face is 48.3mm from the plate and the splines on the input shaft start at 35mm from the mounting face wouldn't the spline be fully through the plate, it's 13mm forward of the flywheel face--sounds good to me I'll measure up that clutch plate in the morning and report back |
| William Revit |
| Wow John, that is certainly some heavy thinking going on early in the morning! Then again, plenty of peace and quiet at that time of night. |
| Tarquin |
| Certainly looks like an interesting project and a nice gearbox. I might even consider one for the B. The Vitesse kit looks very good, but a tad pricey at £2724. Nigel, did they have an offer on at the NEC? |
| Dave O'Neill 2 |
| Dave, sorry I didn't really notice and I didn't ask, I was only interested in whether there was anything reported back on the concentric slave cylinder and where the remote bleeder terminated. I also saw the chap talking to Roger Parker on the stand which reminded me to ask Roger about David Vale (but couldn't remember his name) and his mother and if either were still around, Roger didn't know, do you? |
| Nigel Atkins |
| Nigel Sorry, I don’t think I know David Vale, or his mother. I could be wrong, knowing what my memory is like. |
| Dave O'Neill 2 |
| Hi All.
One very imortant detail I have not reported is that I have now been able to verify that centreline of the gearbox and crankshaft are very well suited. The bellhousing will pick up nicely onto the block with a new adapter plate as proven with my cardboard template . And the depth of the gbox housing below the centre line is no more than the MG box excepting that the gbox tail is a bit bulkier, hence the need to modify the tunnel crossmeber.(You could probably modifiy the existing adapter plate if you had no other option but it would not look very good and not pick up on all the bolting points unless you weld steel into the appropriate areas - not actually totally mad because all the critical holes for the block are already in place.) I have also realised that the Mazda starter location will not readily work because it would hit the distributor. I guess you could replace the distributor with an electronic system but this would be overkill and probably expensive. Just easier to use MG starter by relieving the bellhousing. regards, John |
| j c macleod |
| Any photos John? |
| Tarquin |
| (Sorry of-topic again) Dave, Dave Vale used to do the conversion kits for V8 MGB and his mother kept all the files, based on car reg so subsequent owners could ring up and know what parts were previously sold for their car. IIRC this was before the new lad Clive Wheatley and as Roger told me a direct line from Ken Costello. |
| Nigel Atkins |
| Nigel Is the company V8 Conversions in Orpington, Kent (Dave Vale) no longer around? https://www.mg-cars.org.uk/v8conv/v8convs.html Cheers Mike |
| M Wood |
| John
Sorry I'm late checking in ,I've had a busy day--Went and checked in on a mate today that rallies a Mazda 323 tubo to ask about the small 22 spline clutch in his car--- 323's have, as you mentioned, a 20 spline but his car has a 626 box-22 spline--I thought he ran a normal small clutch plate but he is running a dual plate 7 1/4" competition ceramic setup so no go there-- He reckons 200mm is the smallest 22 spline he has seen and anything smaller will be 20 except VW which has a small 180mm X 24 spline Gathered up some measurements for you today-- MX5 clutch plate-- Outside diameter 200mm Boss length 26mm Thickness 7mm-but worn so expect 8mm new Boss protrusion,forward offlywheel face-4.5mm Boss protrusion,rearwards of rear face-14.5mm The only gearbox I have here is a 6 speed ,so measured from the mounting face of the bellhousing and got 11mm to front of the shaft 35mm to start of the spline 65mm to front of throwout bearing support tube-the spline continues up inside the tube Sat the clutch plate on the shaft so that the fronts of both splines were level giving a full spline length contact then measured from the bellhousing face back to the plate This was 40mm--Pushed the plate right back against the throwout support tube and remeasured--44mm---Checked the shiney area of the shaft spline and sat the plate where it would normally sit in service and remeasured--41mm With your Midget measuring 48mm from the plate to the flywheel face you will need to machine 7mm off the clutch face of the flywheel to get it to 41mm---If that's not possible the bell housing will have to be spaced out from the plate, or a combination of both If you can get it to 41mm then the MX5 200mm clutch ,pressure plate ,throwout and arm etc can be used as std. Flywheel-- The face of the flywheel has a .5mm step in it at 200mm dia to give the pressure plate more pressure on the plate Thepressure plate is held on with 6X8mm bolts at 238mm pcd (measured with a measuring tape) fairly sure it's correct but could be .5mm either way You will only just get that on a 248mm Midget flywheel From what I can measure-work out the Midget flywheel would need the following machining to fit up the Mazda 200mm clutch assy.and make it all work-- 7mm cut off the clutch face of the flywheel An extra .5mm cut from 200mm dia outwards Drill and tap 6 X 8mm holes at 238mm pcd Also there needs to be a recess (hole)in the face of the centre of the flywheel at 128mm dia to allow clearance for the rivets/springs on the front of the clutch plate I've taken some pics but can't get them onto the pc (yet) there's something weird happening there but I'll be back--tomorrow Cheers willy |
| William Revit |
| John, If you post a munged email address I can send you the Quinton Hazell Clutch catalogue which has details of driven plate diameter and spline diameter and number of teeth so you may be able to find another standard application which might suit. Size is 1.3 MB. |
| David Billington |
| Cheers Mike, fancy finding the info where you did! |
| Nigel Atkins |
| Nigel I know this BBS has some info on it! I found a direct website for V8 Conversions too and perhaps a 2018 price list, so perhaps they are still around: http://www.mgbv8.co.uk/index.html Cheers Mike |
| M Wood |
| ETA: Sorry JohnMac but thread (topic) drift often happens, especially if I'm involved.
Sorry Mike I should have put that link up as I found it too "Currently updating 2018 price list Please ring or email for latest prices" so yes perhaps still going. The 'Gallery' has a photo with - "This is my own car I’ve owned since 1976, she has a 3.5 litre V8 producing approx 150 b.h.p. Even with 250,000 miles on the clock she’s still a looker." so probably Dave Vales. I was just interested to see if Dave Vale was still going out of nothing more than idle curiosity, thanks for your help. |
| Nigel Atkins |
| Hi all,
thanks again for all your interest. Thanks particularly Willy fo your measurements, very useful. I have been doing some working out and figuring. You are indeed correct regarding the spline engagement, my gbox measurents confirm yours, I measure 10.5mm from the face to the nose of the input shaft, 35mm to the start of the splines, 65mm to the nose of the release bearing support tube, and approx 10mm more splines inside the tube. With 48mm from sandwich plate/gbox face to the 1275 flywheel face. So just for you to check my thinking incase of brain fade. 48mm + 8mm (friction plate) + 14.5mm spline boss gbox side = 70.5mm, so therefore 5mm beyond the nose of the tube but 5 mm short of the spline limit. Obviously this requires the tube to be machined if not skimming the flywheel by 7mm as you suggest. The other calculation is 48mm - 4.5mm (spline boss engine side) = 43.5mm "closest" reach of splines, therefore 43.5mm - 35mm = 8.5 splines uncovered, i.e. massively engaged. As you say, with the MX5 coverplate bolting PCD at 238mm + 4mm (half of the 8mm bolt diameter) = 242mm outer edge of the holes. Therefore 248mm flywheel diameter - 242mm = 6mm/2= 3mm metal outside the bolting holes, surely sufficient. Provided the pressure plate overhang does not interfere with the starter gear, this could work, might need to spin a bit of the pressure plate daimeter. I am going to pick up an MX5 clutch set to see how this works. The other option is to lathe back the MX5 centre plate to 170mm if there is enough metal left outside of the rivets, to use the MG pressure plate. A simpler option if do-able. ( will also investigate the QH catalogue route - Hi David -what do you mean by munged, I assume disguised to not look like an email?) The flywheel I measured had a 2.5mm step which could be machined away to give a flat face (also lightening it for revs pickup) or spaced up with washers for an easy cheat. Regarding the flywheel face distance, surely this is only an issue with respect to the release mechanism operation. On closer inspection, if we want to keep the starter motor in its original position then we will need to "take a bite" out of the bellhousing as previously mentioned BUT this will probably break into the MX5 clutch release arm hole and certainly lose the existing slave cyclinder bolting holes. This could be overcome by either relocating the starter motor (not easy) or relocating the release arem to the opposite side (do-able but not easy either). Therefore if we adopt a concentric slave we can overcome all these issues and at the same time remove the tube so that the flywheel distance is less critical. This appears to be the Vitesse and other preference also, just concerned about the pain of failure. Hope I haven't bored you all... bedtime reading perhaps :) I will post some pics when there is something worth seeing. Cheers, John |
| j c macleod |
| Me again, forgot one thing.
When explaining this to my nursery nurse daughter who is really getting mechanically interested, she misunderstood me and came up with a better idea! Instead of a top hat bolted to the flywheel, simple machine an extension piece to push onto the gbox shaft and insert into the Midget spigot bush. Obvious really. I think that this would likely have enough connecting length to give good rigidity. The issue being that the MX uses a roller bearing and the MG uses a bronze bush, so you can either make the MX end interference and rely on the bronze bush as we have for many years OR make the MG end interferecne and the MX end large enough for the roller bearing (which appears to something like Vitesse do for the B - possibly using push fit into the flywheel) just a bit heavier. thoughts? John |
| j c macleod |
| And again,
I have been ignoring the gearstick issue assuming that because it has an extension tube then it must be possible to shorten it, true. But it occured to me that to do this will require some work on the selector rod mechanism which will therefore almost certainly need to be disconnected/removed from the gbox selector forks. With no knowledge thereof. A quick google found this excellent webpage http://rotarycarclub.com/rotary_forum/showthread.php?t=17671 which shows detailed photos of the Miata gearbox showing a brilliantly simple gearchange mechanism which I might be able to shorten "in situ" so to speak or at worst remove the tail housing, only six major bolts without disturbing any gears, to give full access. Tempted to do this anyway to achieve the best outcome. Will report when I get that far, still some way off yet! goodnight all. John |
| j c macleod |
| John, I expect you're already doing so but just in case - are you searching for info on the following types of web sites - kit car building, custom/modified, (MX-5/Miata/Eunos/Mazda), unloved car/classics (forget what they're called), MX-5/Mazda racers, classic cars - that's all I can think of. I think Westfield have been using MX-5 components for a while. |
| Nigel Atkins |
| John
Your daughter is spot on with the bush, there's not a problem there- Both the Miata and the Midget flywheels have a similar depth Midget has quite a substantial od sized bush in the crank where the miata f/wheel is a tiddle more dished but has the bearing in the flywheel--both are a similar depth I would say that the miata shaft will well and truely reach into the Midget bush location it should only need a bush id machining out to the miata size (looks slightly larger than a Midget) and fit it in to the crank at the required depth If you are going to make up a whole new bush don't fall into the trap of making it from brass, it has to be cintered bronze for lubrication--------------nothing wrong with running a bush, interferance fit in the crank and clearance for the shaft to spin in it Also,, your p/plate pcd calcs are out '' As you say, with the MX5 coverplate bolting PCD at 238mm + 4mm (half of the 8mm bolt diameter) = 242mm outer edge of the holes. Therefore 248mm flywheel diameter - 242mm = 6mm/2= 3mm metal outside the bolting holes,'' Actually it will be 4mm on both outer edges giving a total of 246mm to the outer edges of the holes leaving 1mm----still should be ok but the longer the bolts the better ''So just for you to check my thinking incase of brain fade. 48mm + 8mm (friction plate) + 14.5mm spline boss gbox side = 70.5mm, so therefore 5mm beyond the nose of the tube but 5 mm short of the spline limit. "" correct How's this for a plan--IF there's not enough metal in the flywheel to take 7mm off which would be the easiest option- Take say 3mm off to get rid of that step leaving the .5mm step from the 200mm dia size inwards and then a recess about 4mm deep to clear the rivets etc of the drive plate from the 128mm dia mark inwards So that's gained2.5mm then cut 4.5mm off the rear boss of the clutch plate to give the total 7mm required for clearance at the throwout support tube--The std miata throwout bearing and arm would take that extra up ok I think 7mm off the flywheel would be easiest / best option and then all the clutch sits in the correct position and the std throwout and arm would work normally--7mm's not much really to take off a flywheel it would all depend on what shape the other side is and if that leaves enough clearance for the clutch plate on the heads of the flywheel bolts here's a pic of the clutch side of a miats flywheel that I have spent hours and hours cleaning up to show you-----------lol willy |
| William Revit |
Ha ha let me try that again--the light must have been shining too bright off the shiney surface
|
| William Revit |
| John, Yes not everyone would post a plain email address so one that has been altered in a a way that hopefully is not picked up by bots etc. I had a look earlier and didn't find any usable alternates but it did show up a few using the same nominal spline but basically partner companies that I was aware of already. |
| David Billington |
| “The issue being that the MX uses a roller bearing and the MG uses a bronze bush...” Early 1275 engines do use a bush, but later models - not sure of the change point - had a larger hole in the end of the crank and used a roller bearing. The ID of the bearing was the same as the bush, as the gearbox didn’t change. |
| Dave O'Neill 2 |
| Hi All,
Thanks John B. The "bad news" is sfter your suggestion I managed to find a very useful clutch parts manual online today to download which lists hundreds of clutch plate sizes. It seems that Mazda were almost unique in using 22 splines and 200mm is the smallest cp of any manufacture using 22 splines. Hence the MX5 cp is as good as it gets. FYI: http://www.national-auto.co.uk/clutch_products/clutch_catalogue.aspx I also contacted a specialist race supplier to check if a custom plate might be viable, they say 180 is smallest they can do and then directed me to Frontline! SO...I have bit the bullet and splashed out a whole £60 on MX5 centreplate, pressure plate, release bearing and propshaft from the glorious Ebay. This is for little used higher spec Exidy clutch kit but cheaper options are available for less than £50 new. When they arrive I shall be able to confirm our musings and see if we can fit a MX5 pressure plate onto the 1275 flywheel. And can also check out the propshaft situation. Thanks for your photo Willy, looks like you been using it as an anchor! However it would be interesting to have the critical dimensions of the crankshaft details, i.e. bolt size, bolting pcd & if regular (the MG one has one hole offset from regular 60 degree centre). And also if back of the FW can be machined to match the crank diameter of 3.5". If so then we could use a MX5 FW but then we would need to address the starter motor as well. Also, well spotted Willy on my error, I kind of felt I had missed it as I wrote it! cheers, John |
| j c macleod |
| Pic of the rear of the flywheel,
Centre hole(bearing) = 35mm Crankshaft locating step=83mm Bolt pattern=6X12mm x 65mm pcd--evenly spaced with no dowels, they use the bolts as dowels Mounting centre section of f/wheel is 9.5mm thick and the bearing is 10mm wide Distance from the end flat mounting face of the crank to the clutch friction surface=23.5mm Spigot bearing is 35odx15idx10mmwide Be aware though that if you go to get a flywheel there are two types as mentioned earlier 200mm =flat with .5mm pop up for the plate surface 215mm= pedastol type with flatter p/plate The Miata starter motor - there is a thin tin plate approx 1mm between the motor and box which acts as a dust cover but also has a round hole in it to locate the starter motor--The starter motor bolts directly to the front of the bellhousing with the plate sandwiched between to locate it We found these flywheels too heavy for competition but for road use they are fine The wheel we run is chrome molly and weighs 7lb compplete with ring gear (next pic) 
|
| William Revit |
| Sorry it's sealed in plastic but I don't want to open it--we have a small rust problem here as you might have picked up on The flywheel and ringgear are all machined out of one piece--this is the pedastol type 
|
| William Revit |
| Hi All.
Thanks Willy for the MX FW dims. Trying to avoid that route if possible. I have been given a lead on a brake & clutch manufacturer only 20 miles from me who may well be able to build a special for me, so I shall give them a call tomorrow to check viability/cost. I was busy last night on CAD [- cardboard aided design :)] making templates of both sandwich plate and gearbox to verify layout and centres and to determine a hybrid of the two for a new sandwich plate. See attached images. This all looks pretty good but will need to reserve judgement on the clutch release arm till I can see just how far the motor reaches into the bellhousing. Q. what is the opinion of the crew as to whether 8mm aluminium would be sufficient for the sandwich plate given that there is not very much area which is not supported by bolting to either block or gbox. My gut feeling is it would be OK. This has the advantage of lighter weight and the ability for me to machine my own on a woodworking router I have available. I will find out the cost of both ali and steel alternatives laser cut by specialists in case it is too cheap to muck about with. I could plasma cut myself from 8mm steel by making a 6mm plywood template to follow but would need to manually drill the holes after. One advantage of steel is the easy ability to weld to it for modification or features whereas I do not have ali welding facilities. 
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| j c macleod |
| trying to add images, will trail them one at a time |
| j c macleod |
| combined template image. Note alignment of centrelines compared to relative positions of engine and gbox. really quite good. Also note area shaded red in starter motor hole which will need to removed to allow starter to fit. New plate will simply be exactly as per bellhousing but with a bit added for the starter and a little bit at top of the block just to pick up the block studs. Tr Register "tax disc" for size ref and fun! 
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| j c macleod |
| Last pic because I couldn't resist a little backdrop of the "bigger brother". But the Midget is just good fun! Also shows a good idea of the reality on the MX gbox. cheers for now, will keep you posted and more pics of the mods to the car when I get there. John |
| j c macleod |
| Oops, pressed sibmit with no pic, so here it is :). John 
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| j c macleod |
| Looking good--
It appears that you are on a winner there still being able to use the original Miata clutch slave cylinder mountings and arm etc it looks to me that the bendix of the starter will be well above and clear of the clutch arm and a bit of metal removed from the bellhousing for the bendix will sort it It's a shame you loose that main bolt in the starter motor hole but the Miata bell housing bolt size and amount are an overkill anyway compared to the amount/size of Midget bolts that do the job fine I'm sure it will be ok There's a bolt just under the starter anyway- The lightweight alloy plates that are available for Midgets retain the original 6mm thickness so your choice of 8mm should do the job easy-- |
| William Revit |
| I take it you're not keen on taking the 7mm off the flywheel face to fit the Miata clutch It would be the easiest option 'IF' there's clearance between the clutch and the crank bolts-- |
| William Revit |
| To mount the starter in its original location I'd drill and tap the plate. This works well for the Datsun setup. Never had a problem in the 10 or 12 years I've had mine, especially if you use the 8mm plate. |
| Martin |
| Hi All,
thanks for your feedback. I like the comments about the alloy plate and regarding the FW Willy, I am open to this if it looks the best option. Waiting for my bits to arrive to see. Just spoke with the clutch specialist and he says "why don't you just bore out the centre of the midget CP boss leaving enough meat to take the boss from your MX5 CP having removed the boss and turned it down to a press fit into the MG boss, then run a bead of weld around it to secure it. Have done several times this for old tractors." Sounds simple enough! Waiting for my MX5 plate to arrive to check boss dimensions. Thought that if I were to also cut the MG boss length back a bit at each end this would then leave a shoulder against the MX5 boss. Then I could run a bead around the "outside" with less risk of fouling the splines. Can always clean them out with a Dremel to make sure they slide nicely. Must go, should be at work. Cheers, John |
| j c macleod |
| The Type 9 conversion uses a Midget clutch plate with the Ford spines put in. |
| Nigel Atkins |
| My type 9 uses an off-the-shelf driven plate, I think from a Hillman Avenger. |
| GuyW |
| Guy you probably done more research than a commercial profession "expert" outfit in type 9 conversions for Spridgets that just borrows ideas from others. Plus, off the shelf doesn't seem as impressive as custom made to the ego or potential sales of confident gentlemen. |
| Nigel Atkins |
| It was chosen with the help of a local independent motor factor who had about 20 boxes opened up on the counter for me to try the input shaft from the T9 box in, untill we got one that fitted. He said it was an Avenger, although I forgot to note down the part number before fitting it! |
| GuyW |
| You mean to say you don't change the clutch every so many years, you don't know how to fully enjoy a (commercial) type 9 conversion. :) |
| Nigel Atkins |
| No, it's on about 70k now and still fine. The gearbox has been out a few times for fitting the concentric slave, but the clutch itself hasn't been disturbed in that time. |
| GuyW |
| IIRC the off the shelf option is only if you have the larger 7.5" clutch such as in the 1098. The mythical 6.5" to suit the 1275 standard clutch I have never located so a custom needed. |
| David Billington |
| Mine is a 1971 car with the 6 and 1/2" clutch, though the cover is a "heavy duty" and cleared more than the bare 6.5", but didn't involve any redrilling. The flwheel was lightened, back and front which gave a slightly larger contact surface with the driven plate. It was all very straightforward, though I sourced or made up all the relevant parts independently rather than buying a complete kit. It was much cheaper that way!
Also, I think the kits are sold with an unnecessary degree of mystery to back up their high price! John's approach neatly side steps this. Anyway, this is off topic for John's interesting and informative discussion, so sorry about that John. |
| GuyW |
| My initial post on this was was on subject . . . but as always I don't mind going off topic - I did think to give a possible justification for the special offering from the low ones as David suggested but I don't feel I need to owe them any leeway. But as you've put back to topic - swapping the middle bit on the clutch plate is a known and used method. |
| Nigel Atkins |
| Regarding backplate thickness from memory the standard cast 1098 and 1275 ones were about 3/8" thick. Regarding the Avenger clutch the QH catalogue only lists the 190mm 25.4 x 23 spline for all models but then it doesn't list the early mk1 Escort 6.5" clutch which I have on my engine but it does list some later models using 165mm 19 x 17 which would suit my 4 speed Ford box. |
| David Billington |
| I had a hilman avenger clutch in mine. It came to bits. replaced with Ford spec QH one. Looks like an MX5 clutch is 200mm |
| Rob Armstrong |
| Hi All.
latest update. The good news is I have received the MX5 clucth CP & PP and have been able to investigate this further. It would certainly be possible to "re-core" the midget CP with the splines from the MX CP but seems a shame to lose the lovely MX friction area, even though clutch capacity has not been an issue with a standard engined Midget, so will investigate using the MX setup on the 1275 FW when I get the engine out. The bad news is I have had to divert my attention to installing a new Central heating boiler to keep my wife happy but I have made a little time to investigate the geastick relocation topic. METHOD: I have proven it is possible to remove the gearchange mech without stripping the gbox. However do NOT do as I did which was to make a schoolboy error of forgetting the reversing action of the gearstick. Following the on-line strip down instructions I found (see earlier entry) which says select 1st/2nd gear line to allow room for the rollpin to be punched through, stupidly went the wrong way due to the reversal and punched it into the rear of the housing causing all sorts of agrovation. I could not get it back (too tight/no suitable tool) or drill it out (too hard) I decided that as I needed to shorten the shaft anyway I managed to cut through the shaft using my jigsaw!(I excuse myself as it was late) Doing it correctly would have made it soooo easy! Subsequently, after removing the 4 fixing screws, it is not quite possible to simple pull the housing & tube straight back due to 2 unseen dowels locating the housing to the gearbox extension. It is possible to lever the housing up sufficiently to cut the rear dowel with a hacksaw (made easier by standing the gbox on its bellhousing). There is then just enough clearance (in my case) to get the housing to clear the front dowel. Note the rear dowel is in a blind drilling but the front dowel is not blind so could probably be accessed under the tube to be tapped down to give max clearance if it should drift upwards making it more difficult. I suggest you take good notice of the selected gear on pulling the housing back as you dont want to lose selector engagement (if this is possible) requiring the front of the box to come off. I intend to find reverse gear as an absolute proof of position. The shaft tube is push fit on rubber seals only. I shall cut the gstick housing fixing bracket off as short as possible to allow the housing to close couple to the gbox but I have decided to "line-bore" a hole straight through the rear of the housing to allow the shaft to poke through the back to maintain the axial support for the gearchange to ensure that it does not go sloppy. The shaft can then be cut off to the minimum length to facilitate this and to reduce tunnel fouling issues. I will then use a blind tube to keep the oil (minimal) in the housing but mostly to protect the shaft from rust. The housing will be supported by a steel bracket fabricated to pick up the 4 screws which fix the housing sideplate and then down to the original 4 fixing screw points. I have yet to get the engine out to determine the exact gstick position and whether I need to gain every last mm. This is the next step. NOTES: It occurs to me that it would be a good idea to drill and tap a hole(6mm?)next to the rollpin (of painful experience) in the gearstick pickup. This will allow the shaft to temporarily be fixed with a screw to allow the gear stick position to be determined & adjusted before committing to cross-drilling a new hole. It would also allow for a roll-pin to be tapped in temporarily to provide a guide for a suitable sized pilot drill to accurately drill through the shaft. This can subsequently be opened up to the roll-pin size. I am trying to reduce machine shop work as much as possible to make it easy for others to follow. I am writing this whilst away from home so no pics (watching the F1 GP on catch-up) but will correct this next time. cheers All, John Mac. |
| j c macleod |
| Hi All,
I will keep it short. See pic of gearchange mech removed (including my gaff)secured off centre with 2 bolts for convenience. Note the dowel sitting in the foreground and drilling for same under the shaft. Also note the laarge hole in the rear of the gearstick housing which holds a spring loaded plunger for gearstick centreing. THIS is where the roll pin should have gone, if you miss it then you muck yourself up! Of great interest is the propshaft details. (will upload image also) If my earlier measurements prove corrrect, then the MX gearbox output distance is very close to the MG output distance such that it is possible to use the MG propshaft. Measuring the spline yokes of the two reveal that they are of very similar dimensions. So much so that it may well be possible to simply bore the UJ holes of the MX5 out by approx 2mm such that it will accept the MG UJ. Ideally one would machine appropraite circlip grooves but an easy alternative would be to use an appropriate thickness washer on each UJ bearing cap to centre the UJ and then fix the washers in place with 2 or 3 vey quick spots of weld to each, I beleive that the washer would protect the bearing from heat damage if cooled ASAP. If the shaft length is right then this will be so convenient. I hope to remove the engine & box this weekend, life permitting. cheers all, John. 
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| j c macleod |
| propshaft image as promised. MG obviously the smaller item but larger UJ bearings. MX5 bearing are staked in but stakes could Dremelled away. Can't quite make out how the MX5 propshaft tube is assembled, does not appear to be welded unless friction welded but does not look like that. Any clues anyone? john 
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| j c macleod |
| John You 'might' be lucky enough and the Midget u joint caps 'might' fit the miata spider A lot of the spiders (crosses) are the same size with different size caps for different applications---luck will play a big part in that though If it did work out you could run miata yoke and u joint with midget caps and shaft I wouldn't disturb the uni in the yoke till you know though --bit of a one way trip from there |
| William Revit |
| As Willy says, you might be able to use one or the other U joint depending on which caps are available. Again, going back to my Datsun 210 box, that's how the Datsun yoke is connected to the Spridget prop shaft. There is a noticeable difference in the two caps. It's been a while since I had it out so I don't remember which was which but you might be able to go to your local friendly parts supplier and get to try out different combinations. At worst, you'll have to buy joints and mix and match the caps you need.
I'm interested in this project the Datsun boxes are starting to resemble hens teeth here in the States and Ford boxes are just as rare. |
| Martin |
| Hi Willy & Martin, I see what you are you saying, that the MG spider diameter might be the same as the MX spider diameter but the MX cap may be thicker or rollers bigger so they can "Mix & Match". Interesting possibilty if so. I shall wait until I know if the MG shaft length is acceptable before finding out because if not then I shall have to cut & weld the shafts so might as well leave the MX5 UJ untouched. Will keep you posted & thanks for your continued interest. Cheers, John |
| j c macleod |
| John, The Mazda shaft looks to be friction welded to me from the characteristic 2 rings butted against each other and curling back away from the centre. Some applications clean that detail up but it's not essential. Have you measured the UJ bores and width across the caps as they could be the same. The UJs on the sprite are the same size as used on some rather larger engined cars. |
| David Billington |
| Hi All,
in the interest of progress I decided to shorten up the gearchange position as far as possible but have left a bit of shaft spare so I can move it back a little if required (though unlikely) See attached images of the exercise. First I cut of the attachment bracket flush to gearshift body. Note how I left a little nodule on the bottom forward screw hole to maximise the gasket area. Simply hacksawed from the rear to the nodule then cut back the other way leaving the nodule. I then coated the inside with marking blue (felt pen) and slid the housing back on the shaft so that I could mark a circle with a sciber around the shaft. Note you could cut the shaft off at this point (cutting dimension to follow) to enable this to be done more easily. I then careful measured/judged the centre of the scribed circle to centre punch it. Then drill though with a small pilot drill. the pilot hole was enlargened using a step cutter to as close as I was able to the scibed circle (approx 0.5mm smaller) I then simply used a Dremel type machine with a small abrasive sanding drum to carefully open out to full size. when I was close I used the gearchange shaft which I had now cut off (after I determined the max required length by sizing up with the newly shortend housing)to both keep testing for fit and when really close tapped fairly smartly with a hammer to make a good tell-tale mark to dremel too. I figured that as long as the general fit was good the its absolute circularity would not be critical, however it is pretty darn good! The fit is sweet . I then offered th housing up onto the newly shortened gearchange shaft and determined that there was interfernce between the housing and the gearbox due to a nicely curved detail on the gbox casting. Therefore careful shaping of the housing front corner and also dremeling away a gbox seam flash (minor) allowed areally snug fit so that an O ring or/and some RTV will seal it perfectly. It also happens that the fit og the housing against the gearbox is really quite good allowing almost no rocking movement at all having taken care with the fitting. It now requires me to make up a bracket to pick up the 4 housing cover screws & the original 2 rear bolt holes. And also to refit the gearstick pickup slider. Note that it is very difficult not to lose the gearchange engagement during the process but it is possible to feel your way back into place rather like a safe breaker. It is a bit worrying when the rod becomes disengaged and is obviously in free space, however I was able to find reverse gear as an absolute for position and also 4th gear which you can determine by marking the input & output shaft with a felt pen snd prove 1:1 ratio by turning the input shaft. This is where my intention to drill and tap a clamping screw initially will be so useful, even essential to be able to fix the shaft to enable it to be cross drilled. Images to follow. (apologies for less that great phot quality, only have an old phone available at present, my better one failed) cheers, John 
|
| j c macleod |
| Image of initial assembly showing how nice the fit is. Hoping the gearstick position is acceptable but quite confident as very close to MG distance. John 
|
| j c macleod |
| Pic of housing fetling required to allow close fit up to gearshaft exit. Unfortunately not terribly clear but illustrates the method. Will report the shaft cutoff dimension when I report the fixing bracket manufacture. Cheers, John. 
|
| j c macleod |
| Hi all,
quick update. Life and weather has got in the way and I have not been able to remove the engine/gbox assy as hoped. Due to pressure of work this may not now happen before Christmas but I shall try. The principle reason for the update is to confess to another senile "brain fart" as I sometimes call them. Having ascertained that there is up to 4" available to remove from the gear stick position, in my impatient haste to see progress this is precisely what I did. However on thinking back and re-measuring the MG stick position I realise I had only intented to remove 2"!! This is reversable but will require me to create a more complicated fixing bracket than would otherwise hvae been necessary. It would have been acceptable to cut off the alloy fixing bracket leaving two of the fixing holes intact, thus providing a much neater/better way to refix using a simple flat plate drilled appropriately. It would also have the great benefit of leaving sufficent distance between the shaft guide holes to do away with the need to drill through the back of the housing as I have done. Moral of the story, "more haste less speed". I wanted to come clean so that in the unlke event that anyone was close on my heels they did not repeat my error and or had spotted my folly. Also I have found that it is all too easy to lose the selector engagement such that I may be forced to split the box to get it working properly again. It does work but seems very tight. It occurs to me tha the fix for this is to remove the neutral indication switch, place a piece of tube (maybe plastic) on the end of it and screw it back in tight to lock the shaft in the middle of the 1st/2nd gear line before attempting to remove the gearstick housing. One good note is that drilling and tapping the gearstick slider block with a 6mm screw for tempory trials works very well. I am slightly tempted to complete this instalation to prove fit and efficacy then repeat with another gearbox to get it right for "publication" though will still keep you guys up to date for your interest and continued assistance. cheers again, John |
| j c macleod |
| Hi all.
Quick update. Engine & gbox now out and split. Been measuring up this evening and am confident it can be done without too much modifications to bodywork. Only need to remove the existing box cross member and some tunnel floor and re-fabricate. My biggest question is now the clutch. I think I will go with the Mazda centre and pressure plates. Will either have face-off the flywheel flat and re-drill or could simply use spacers under the pressure plate as the centre plate is almost perfect fit to the raised section of the 1275 flywheel. I hope to progress a bit over the Xmas break but see how it goes. Cheers all, John |
| j c macleod |
| Hi John, hope you're well and having a good holiday.
First I should apologise for not reading your first post properly. If I had I'd have seen that your Midget is an A series not another 1500. It's only relevant to me because I know nothing about A series Midgets (and truthfully not much more about 1500s, although I have one). Secondly I began to wonder if you could sidestep the entire starter motor location issue by using a Dynastart. It's usually assumed they went out with the Ark and the last example I had was on a 60s Volvo MD1b single cylinder diesel. But it turns out that they are still commonly used on small diesel plant, small aero engines and (of all things) golf buggies. Hitachi and, I believe, Bosch still make them but they seem to follow the American convention of calling them "starter/generators" rather than Dynastarts. It would mean reverting to dynamo charging but that's not necessarily a drawback with modern solid state regulation. It would also mean you could bin the ring gear and usefully lose some rotating mass from your flywheel assembly. And you would have no need to cut the bell housing so it wouldn't have to compromise the clutch actuating gear. Just a slightly batty idea born of a rare and unexpected night off-duty and a couple of G'n'Ts, but I reckon it should work. How's it going otherwise? Cheers. |
| Greybeard |
| Hi Greybeard,
thanks for the contact. I have never considered a Dynastart although I did know what they are. I am not worried about cutting the MX bellhousing as it seems to be pretty well made and keeps it simple. However I have been moving forward steadily and now have 2 decisions to make. 1. Do I use the Mazda or MG clutch assembly. My head says Mazda so the future parts are off the shelf and has much greater surface area for wear, my heart says use a modified MG centre plate with MG pressure plate since i) iliminates flywheel modification & ii) the Mazda clutch assembly is more than a kilo heavier and mostly due to greater diameter,so NOT very desireable on a humble 1275. I have been reading David Vizard regarding maths of the flywheel weight effect and as you say it is not to be diregarded. 2. Do I: i). use the Mazda spigot ball bearing. Cheap standard 2602 item needing only a simple adaptor ring machined to make it a press fit into the flywheel BUT then causes a 5mm interference with the gbox input shaft tube (the release bearing carrier) this can be overcome by removing 5 mm from the tube as there is spare spline length, and/or 2mm could be gained by grinding a little off the centre plate boss and could also skim the raised section off the flywheel to gain another 2.5mm. OR ii). machine a new phosphor bronze spigot bearing to press into the flywheel to pick up the end of the gbox input shaft. This can be set deeper into the flywheel than the ball bearing can be so avoids the gbox tube mod. I have been looking at the adaptor plate and I am seriously considering simply welding a few shaped pieces of 8mm steel to the original plate to make up the missing areas. This has the benifit of retaining all the acurately drilled holes of the original. Then having sorted the spigot bearing you can simply bring it all together on perfect centres to mark though the bellhousing to drill the gbox fixing holes. You could use a pilot drill through a mandril reducer to pilot drill the plate directly. Alternatively I could use a 6mm aluminium adaptor plate (I already have a piece "in stock") bolted to the existing 8mm steel plate. This would in truth only be acting as an adaptor/spacer with the load being carried by the steel plate and would then provide the required clearances. Now I discuss it all I am somewhat favouring the MG clutch with Mazda ball race and modified sandwich plate as I can do all this in house and would be easy for others to repeat. I just need to locate a "dead" Mazda centre plate for the spline boss as it will hurt to much to cut up the nearly new Exidy sports plate I scored! Thanks again for you interest as it makes me think things through clearly. Hoping to get it going in the next month if possible fitting it around my work. Any comments from those following greatfully received as always. cheers, John P.S. attached is a pic of the early trial bring together which as you can see is rather promissing. :) (pleaase excuse the mess in the garage, trying to get shelving up!) |
| j c macleod |
| No pic. |
| Dave O'Neill 2 |
| John, You might find differently but I wouldn't try and weld onto the original adapter plate as I always got the impression they were an iron casting not steel, if so the welding is likely to fail. |
| David Billington |
| John, if you change your mind about the MX5 spigot bearing may I sound a note of caution about your alternative of using phosphor bronze for a custom bush? It would really need to be sintered bronze aka Oilite - "fozzie" would wear very quickly I think.
Happily, Oilite bushes are easily available at modest cost and if there isn't a suitable stock size they can be custom made, or you can get Oilite bar stock to machine yourself. Here's one example: http://www.getyourbearings.co.uk/oilite.html?gclid=Cj0KCQiAsJfhBRCaARIsAO68ZM5syaIiSAOQMWT7ebiwGZr6A_h8eXeTjxbvNG9Gsa9Q2siaPM4RI3EaApVwEALw_wcB That said I suspect you're absolutely right about the Mazda bearing; it's proven to be suitable for the task and good from the point of view of future-proofing. |
| Greybeard |
| Hi all
I am enjoying reading this thread immensely. I have nothing technical to add, just admiration for the technical knowledge and ingenuity. Makes me think of Donald Healey, Alec Issigonis, Eddie Maher, Don Moore and others in the mixing and matching of existing production BMC/BLMC/BL parts, with minimum necessary mods to create new models and uprate existing types. Cheers Mike PS I bet the original Mazda Mk1 MX5 design, production and dev engineers would be fascinated by such an approach, as they must have been old British sportscar enthusiasts at heart in what they created themselves. |
| M Wood |
| Good point on the sintered bronze bush Grey
Most auto electrical places keep a good range of sizes for generator bushes I did a gearbox conversion in a B back in the 70's and made a straight bronze bush for it, First long trip in it, when I went to pull up to refuel the shaft had grabbed in the bush. It was a hell of a job getting the box out and eventually when it came out the bush was still seized solid on the shaft and had to pull it out of the crank with the box to get it out and then it wouldn't fit through the splines of the clutch plate, so had to cut a hole in the bellhousing to get at the pressureplate bolts -What a disaster that was about a thousand miles from home- The bush had had heaps of clearance and lubed but just the vibration of running along in top gear over a long distance ,it just fretted together-just driving along it wouldn't have been spinning at all Main thing with the sintered bush is to give it a good lube up before fitting it, It amazes me how porous they are when you push the oil through them The question-- Are you a soaker or a pusher I'm too impatient so, I'm a pusher ha ha ha willy |
| William Revit |
| Willy. I'm a soaker. Actually more of a cook - we used to simmer them gently in gear oil! They are used in underwater camera pan&tilt units because they tolerate a bit of salt water contamination better than rolling element bearings. But I still reckon John is right about the Mazda bearing. Far less hassle I think. |
| Greybeard |
| Yeah, less hassle but probably not any more reliable than a bush, they do fail
Shame you're half a world away John, I've got that many dead Miata bits laying about it's not funny anymore---the postage cost makes it useless for me to send you a dead clutch plate Maybe if you went and visited your local Mazda shop ,they might have a dead plate laying about waiting for you Grey, this is how I fill the bushes up- Sit it on the palm of my hand, fill it up with gear oil, put my other thumb on it and push like hell till it's right through- Saves a lot of time 
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| William Revit |
Half way full ,don't ask about the scar on my hand
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| William Revit |
All done ,ready to fit
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| William Revit |
| Willy forgive me please, I was re-reading the thread and finally noticed that you beat me to the sintered bronze comment by several weeks! D'oh! |
| Greybeard |
| Grey No need for a please You have been granted an automatic pardon for your sins Happy New Year buddy |
| William Revit |
| Cheers mate, and a good New Year to you. If I'd known the automatic pardon was in the post I might have done some more sinning haha! |
| Greybeard |
| Hi All,
happy New year to you all! Thankyou all for the heads-up on the phosphor bronze issue, point taken regards Oilite material. I am 99% set on using the MG clutch because of the mass issue, that said it does present another issue where the pressure plate is deeper overall than the Mazda leaving less room for the release bearing. I have been busy looking at clutch release options OPTION 1 Use the MG release arm complete with the carbon release bearing because the arm dimensions are amazingly close to the Mazda set up. It would simply require a fabricated mounting for the pivot bolt screwed into the mazda tapped hole but it will require the mazda CRB tube being Dremelled off to allow the MG cover plate to operate over the input shaft. However the clearance of the pressure plate hub over the splines is miniscule raising the fear of interference squeal (or worse) on pressing the clutch. It may be possible to create a tiny bit more clearance in the hub. I note that in some images online the MG clutch uses a ball race direct on the PP fingers. Is this for the 1500 only or could one use one if these pressure plates? OPTION 2 remove the PP cntre-hub and use the Mazda release bearing and arm. This requires the tips of the PP spring fingers being cut back about 3mm to give clearance over the Mazda CRB tube and also changes the mechanical advantage on the release fingers because it effectively reduced the finger length. However I have done some simple experiments on this using a lever and spring balance to compare the original MG release force to the Mazda CRB on MG pressure plate and it appears to be less than 10% heavier, so acceptable if true. I am therefore tempted to: 1. Create my 6mm aluminium pressure plate (started already) and attach to the MG sandwich plate. (this allows the use of the Mazda spigot bearing) 2. machine the spacer for the spigot bearing (repaired my old lathe for the purpose - fitted a fresh motor!) This allows the alignment assembly to take place to enable the ally plate to be marked/drilled. 3. Bring the whole lot together temporaily using the adapted (butchered!) MG pressure plate. Will use a new PP if it works OK. 4. temporarily connect the Mazda slave cyclinder to the MG master cyclinder whilst the engine is on the ground under the car with the benifit of a 4 post lift aquired this year:) 5. prove that the clutch will operate succesfully, perhaps even starting the engine by temporary hook up of fuel and electric. The biggest problem being the lack of propshaft to keep oil in the gbox, although thinking about it the Mazda tail shaft is recessed so can simply cover with a blanking plate. If this is all good then safe to progress to chopping the floor and making up the propshaft. cheers John, PS I have found a clutch remanufacturer online who will supply a recon Mazda 626 plate for £17 if a local dead one drawsa blank so not too bad. PPS will attempt to attach pic again! 
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| j c macleod |
| Your Q about using a ballrace directly on the PP fingers - yes, most racers run this method, usually with a 7.5" clutch as supplied by Peter May (and others). It's the same clutch used by a lot of Caterham racers. |
| David Smith |
| John, have you considered using a concentric slave cylinder with in built release bearing and guide fitted inside the bell housing? They are fairly compact and mine made using a Ford slave works well with an unmodified 1275 clutch. That's with a T9 box; maybe the Mazda bell housing isn't large enough? |
| GuyW |
| John
I think the secret of making any good conversion is to keep it as simple as possible and use as many over the shelf parts as possible If you are going to run with the extra 6mm plate it's back to where you can run all the Miata clutch assy, t/out bearing, fork etc I think we calculated 7mm off the flywheel earlier so the 6mm plate would cancel the need for machining apart from the 0.5mm step in the face required to run the Miata clutch assembly Another option to consider is that if you were to spin the face off the flywheel to get rid of that step to fit the Miata p/plate, the amount of metal removed would just about balance out the extra weight of the p/plate maybe willy |
| William Revit |
| If you consider the stock carbon thrust approach. Instead of the carbon you could use one of my roller release bearings which is a direct replacement. It is possible that I could modify for your application to give more clearance between the thrust and the clutch cover pressure pad. This would give you somewhare between a 1098 and 1275 offset according to your need. Alan 
|
| Alan Anstead |
| - Off-topic . . . Alan, did you get the oil filters from NEC? Cheers. |
| Nigel Atkins |
| Nigel Yes thankyou. I made a donation at Bears. Alan |
| Alan Anstead |
| Cheers Alan that was very good of you, there was no need for you to have done that but thank you very much. A mate gave them to me as they didn't fit his Sprite so I just wanted passed them on to those that could use them. If we're at the March NEC another mate has given me a box of 35a glass fuses you can use or pass on, no donation required. - And, back on topic . . . |
| Nigel Atkins |
| Nigel I expect to be 'front of house' on the Midget & Sprite Club stand at NEC in March although I am not expecting to do any demonstrations as in past years. I will have some of my release bearings for sale. |
| Alan Anstead |
| Right you are Alan, hope to see you there then. I did notice the bearings on display last year - too later for me, I finally had to go concentric last year, of course with my luck I got one that sends the fluid black! |
| Nigel Atkins |
| Hi Guys, thanks for the mass New Year response!
Thanks David, thats useful regarding the ball race on the fingers, good to know. Thanks Guy, concentric was my first thought but decided to try standard first as it will allow a bit more flexibility/adjustment/fixability without gbox removal. However will see how this goes... Thanks Willy, my latest measurements appear to show that it will JUST fit using the Mazda CRB set-up without needing to skim the flywheel. My calcs of weight removed by skimming the front says about half of the Mazda PP and CP. The rest could be removed from the back but the Mazda rotating diameter will be quite a bit more with more impact, however I think it would be OK if I eventually go that way. If someone else follows me but with a hot engine then the Mazda clutch would be the way to go. Still tempted to lighten the flywheel in my lathe just for the extra pep. Thanks Alan, trying to use the Mazda CRB and lever at he present but if I go back to MG thrust bearing then I could well be in contact. Being "new" to Midget land I was unaware of your offering. Thanks David (from ealier response) The plate looks like steel to me and I think it would weld OK but there is a part number stamped or cast into it so you do raise a valid question. It may weld fine but break in use if the metal is too disimilar. PROGRESS REPORT Today I have purchased a dead MX5 plate from the Ebay breakers that my prop and Mazda clutch kit came from and have rough cut out the 6mm spacer plate and drilled though all the holes using the steel MG plate as a guide. Also cut 3mm off the PP spring fingers to allow it to go over the Mazda gbox tube. Next step is spigot bearing and bring it all together. cheers, John |
| j c macleod |
| Very interested in this but eventually fitting into an Austin A35 with a 1275 Midget engine. At least I don't have to contend with the closed gearbox tunnel on that like on a Spridget. On a separate note club members are very interested in Alan's roller-bearing clutch release. Hoping to get to NEC in March so I will try and introduce myself ... and maybe our Club Spares Team! |
| G Taylor |
I am contactable at alan dot anstead at btopenworld dot com. I have just made another small batch of 1275 release bearings.
|
| Alan Anstead |
| Very interested in this but eventually fitting into an Austin A35 with a 1275 Midget engine. At least I don't have to contend with the closed gearbox tunnel on that like on a Spridget. On a separate note club members are very interested in Alan's roller-bearing clutch release. Hoping to get to NEC in March so I will try and introduce myself ... and maybe our Club Spares Team! |
| G Taylor |
| Hi All.
REQUEST FOR INFORMATION Latest update. Have made the spigot bearing adapter ring and that works well. It all lines up well now. I have cut a 40mm slot in the gbox bellhousing for the starter bendix which also works well. However I have one setback. I have removed the boss from the Mazda CP and machined down to 28mm diameter. Then set about machining the boss of my old dead MG CP for practice and found that at 27mm the boss comes to pieces!. Turns out it is a composite component made from 2 (possily 3) parts with external splines which pass the drive into the CP buffer spring assembly. I could have dismantled it first to find out how it was built but wanted to try machining it in place as did not expect this to happen. A bit difficult to describe but anyhow this makes it much more complicated to re-boss the MG plate. If I turn the Mazda boss down as far as I dare (about 27mm) this will make the spline roots very thin and liable to break and also make welding tricky as they will likely burn through and need cleaning out. And also no telling how strong the CP itself will be. Could easily find myself with no drive! I will dismantle the MG clutch centre to allow a rethink but if this works then need to re-rivet the 2 halves back together. Not impossible but just more work. Also had I not already machined the Mazda boss down then I would still have enough material to make it do the centreing :( I will attach a picture of the centre plate with Mazda boss pressed in (purely coincidental that the boss outer spline ID equals the 28mm of the Mazda boss diameter I chose to machine to). Demonstating the problem in that the missing pieces of the MG boss allow the boss centre to move around! OPTION 2: Mazda clutch complete. But need to compensate for increased weight. THEREFORE REQUEST: does anyone have a drawing of how to lighten the 1275 flywheel. The archive material all seems to be for smaller engines. David Vizard says OK to thin a mini flywheel down to 1/2 inch thick in his masterpiece "How to Tune Your Mini" so I imagine that is true here also. (I did that a number of years ago to an 1100 mini FW) I can't take anything of the front face diameter though as the Mazda PP obviously requires it. I v. nearly bought Vizards A series tuning book to find out but a review says it does not include the flywheel!!! (hard to believe). cheers for now. John 
|
| j c macleod |
| 10 seconds with google provides this link, wherein lies a reference to your answer... http://www.spritespot.com/phpBB3/viewtopic.php?f=10&t=6170 |
| David Smith |
| Lightened flywheels are mentioned in Daniel Stapleton's Midget and Sprite High Performance Manual. He has several references to Peter May Engineering and also a reference to a 7.5" AP uprated clutch. I've only got it in Google Play Book mode so it's not easy to "copy" .. |
| G Taylor |
Peter May flywheel for 7.5" clutch
|
| G Taylor |
| John, Did you look at whether the MX5 flywheel would fit on the Midget? Someone is trying the same on Farcebook with an A35 and "elongated" the flywheel holes to fit it to the Midget crank! (I don't know yet how much elongation was necessary!) |
| G Taylor |
| Is the PM flywheel a lightened, standard item, or a complete new item, machined from a different material? |
| Dave O'Neill 2 |
| Peter May one looks newly machined .. there is an image on my previous post but I think you need to click on the "Image" link just below it! And following on from me post about the MX5 flywheel it's a matter of 0.5mm difference in PCD!! I've asked the chap who is working with his Father to put the MX5 gearbox in an A35 to get us some photos. they have used a Honda Jazz starter .. small enough to fit under the A-series distributor. Gearbox bell-housing needs "adjustment" .. :-) |
| G Taylor |
| The lightening details are in the attached picture, but I cannot find the source document at the moment. Richard 
|
| Richard Wale |
| GT If the Miata flywheel was used with the miata g/box I would have thought the miata starter would have been the choice, I wonder why the Honda starter I sent John all the measurements and pics of the flywheel earlier on in this thread but he appears determined to modify everything to fit a midget p/plate----why--?? Or at least cut the std flywheel back and run all mazda clutch assy It would be a whole lot easier to keep it all std mazda-------keep it simple willy |
| William Revit |
| Mounts too high up so interferes with distributor |
| gazza82 |
| spot-on Richard; that ties in with the info in the googled link I gave a few posts back. Specifically Leyland ST Special Tuning publication AKM4168. |
| David Smith |
| Willy I wonder if it's because the Honda starter is designed to fit the other side of the engine, so if it is fitted to the right (driver) side the piggyback solenoid would be "underslung" to the motor, giving clearance above it for the dizzy. Does that seem plausible? Edit: or could it be a question of the rotation? I don't know which way the Mazda engine turns. |
| Greybeard |
| All good points BUT if he's making his own back plate-- put it where it fits---------- To me it's just getting messy, where it could be simple Good thought on the rotation Grey, some of them Honda engines spin the other way, not sure about the Jaz though |
| William Revit |
| “or could it be a question of the rotation? I don't know which way the Mazda engine turns.” We’re not talking about a Mazda engine, just the gearbox. Also, it doesn’t matter which side of the engine it’s mounted, it will still rotate the same way, unless you flip the motor round so that the body is facing backwards. |
| Dave O'Neill 2 |
| Okay I checked and the engine spins the same way as the A series. Of course, otherwise John would not have selected the Mazda gearbox.
Some Japanese engines do spin the other way,as Willy says. I understand of course Dave that the starter will turn the same way regardless of position; what I was referring to is that the nose casting on the Honda motor is such that the open side where the pinion is exposed is opposite to that of the Mazda unit, so that in the position on the right side of the engine the Honda motor would have to be inverted to engage with the ring gear. Meaning that the solenoid would be underneath it out of the way. John has opted to position the motor in the original place, referenced to the engine, but the Honda motor may be simply a different approach to the same problem, besides it being physically smaller as G Taylor said. Apparently small enough to miss the 1275s distributor. |
| Greybeard |
| Has anyone tried dismantling a Mazda clutch plate? There are pictures online of a 4 spring variant, perhaps the centre plate from this could be adapted and fitted into an MG clutch plate. |
| AdrianR |
| I'll try and find our why my A35 colleague used the Honda starter but assuming it is down to size. All I've learnt so far is the chopped a small piece out of the bellhousing. I'm hoping to get pics after the weekend ... |
| gazza82 |
| Hi All,
quite a discussion going on out there. :) Interesting regarding the A35 to Mazda, I look forward to the results. I trust the gbox is good for direction, I assumed that because they are fitted to the MGB then they would be going the same way. Bad news if not as the teeth will all be meshing on the "back" side, will they not. And various other issues could arise with oil flow, etc. Thanks to G Taylor for the lightened flywheel diagrams, strangely the dimensions do seem to tally with my own FW. It is possible it has already been lightened a bit, what is the weight of a standard FW? Thanks Willy for your comment. I am torn. I have decided to use the MG plate if possible simply due to the extra weigth penalty of the Mazda setup. It looks like I could just about compensate in simple terms by FW lightening but more of the Mazda weight is on the outside diameter and would have a greater effect. I have not looked at a Mazda FW because I don't have one and the breakers are all a long way from me. HOWEVER, see attached images (hopefully) of my progress, I value any comments (he says foolishly!). Actually what I have done is not very hard, assuming it works successfully, and would be easier if you learn from my mistakes/discoveries. It turns out the MG plate centre is made from 2 parts, the centre splined boss which provides both drive and centreing, and the flate spring carrier plate which transmits the drive into the clutch proper. There vey small teeth which connect the boss and plate together, possibly a press fit with the plate cutting teeth into the boss. Then the boss is swaged(?) so that a collar of steel is forced onto the plate to hold the two as one. By shear fluke I chose 28mm as the machined diameter of the Mazda boss which turns out to be press fit into the plate even cutting its own teeth slightly. I have been forced to press the centreing collar from the MG boss )which only became a collar as I machined it off) onto the Mazda boss an use spots of weld to keep it in place. I then welded the spring plate to the mazda boss in lots of short burts diagonally opposed to A) keep the assembly square and B) avoid burning through the collar and ruining the boss splines. I had a an extra issue to watch in assembling it all square but someone copying would not machine the Mazda boss all the way, but leave a shoulder to act as the centreing collar and give a square collar to press onto. I will produce a drawing of same in due course. Dissambling the MG plate is best done by drilling swaged "heads" the rivets almost off and then using a sharp chisel ( an old wood chisel worked fine) to cut then off flush allowing the plate to be levered apart carefully. Any slight distortion is easily straightened. NOW THE BIT FOR COMMENTS. Initialy I intended to machine new rivets to pattern and reasemble as per factory but then I decided to drill the existing rivets through at 6mm having squared up the of the rivets and reduced the remaining shoulder to 60 thou., the thickness of the clutch face plates. Thisi allows the rivets to be re-used in conjunction with high tensile allen bolts, i.e. having some plain shank to pass the drive, not just thread. I am hoping that 4 plain shanks will take the power because the rivets are actually still taking the drive in their shoulders. I will diagram all this at a later date. I have currently assembled it with some ordinary 6mm nuts but these should be higher grade and I have left some threads showing which I intend to peen over to ensure they cant come off. I could even put a spot of weld on them I suppose. All this will allow a clutch to be rebuild quite easily in future only needing new screws for reassembly. Do you feel that this method is too risky. One issue I found was the act of welding the collar shrunk it very slightly making it tight on the gbox shaft so I had to clean the splines with a Swiss file until the plate would slide on nicely. Not a big deal. I feel that the route I have adopted, if succesful, is the easiest to achieve in the garage requiring only a small amount of lathing and not too precisionat that. If this does not prove succesful then I will happily go the Mazda onto the MG flywheel route. Sorry for another long missive, will attcach a few pics. Cheers, John 
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| j c macleod |
| pic 2 spring plate welding machined 
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| j c macleod |
| pic 3 collar spot welded back on. Would not be necessary doing again by leaving equivqlent on the mazda bos. 
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| j c macleod |
| Pic 4 side view of assembled plate. Will use higher grade nuts and peen over to ensure cant come loose. 
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| j c macleod |
| Precision Clutches of Henstridge would probably be able to replicate a clutch plate to your design for those wanting to follow in your footsteps once your project is finalised and proven. |
| Alan Anstead |
| Looking good John
The bolts will be plenty strong enough The original rivets are fairly soft old things,nothing special The solid centre competition clutch plates for miatas have the centre spline riveted into them with 6 piddly little rivets about 3-4mm dia at about50mm pcd and they take big horsepower without any issue The only possible issue I can see with what you have there is that the pressure plate fingers 'might' foul on the bolts when the clutch is depressed---don't know Maybe if they are washers under the nuts,go washerless instead and cut the nut depth down to a minimum and loctite and peen them willy The Mazda motor spins the same way as yours so your gearbox panic moment doesn't need to be The comment about the Honda stater motor was based on 'some' Hondas, spin backwards and using the starter out of one of those reverse spinners would wind an MG engine backwards unless the starter was modified |
| William Revit |
| standard 1275 flywheel is 15 lb 6 oz. |
| David Smith |
| David, just out of interest, do you know what standard 948 and 1098 flywheels weight. |
| Nigel Atkins |
| sorry Nigel I don't; my records are obtained by weighing bits of engines destined for the racecar and I've only ever used 1275s. |
| David Smith |
| No problem, thanks for replying, I was only asking out of curiosity. Possibly it's something in Daniel's book, or there used to be someone on this forum, or another, that was very interested in the weights of components and parts. |
| Nigel Atkins |
| Just for Nigel Standard 1275 carbon clutch release bearing = 210gm although there will be probably variations between brands. My roller release bearings = 250gms. Alan. (Waiting for the next instalment, and pictures, of this interesting project) |
| Alan Anstead |
| Thanks all.
short evening this evening as had to fit brake pads to my Navara for MOT tomorrow, much less interesting. However, thanks Willy for your confirmation of my thoughts. I had already done a cursory check of the clearance in the pressure plate but not assembled so I have now bolted it to the FW just on the bench and depressed the clutch fingers with G-cramps it looks fine. But I decided to lose the washer under the nut as they are flange nuts anyway with serated face for grip and just to go with them as they seem pretty tough. I then wrung them up as tight as I could, ground each bolt back till 2 threads showing then peened each one over. Looking very good. (no pic but will take one for next time) Now proceeding to fit my spacer plate, I need to fit a longer top cente dowel to locate it but had to drill the old one out as just chewed up as I tried to remove it. Will make new dowel tommorow night. The fixing holes in the Mazda gbox are huge, 14mm and slightly tapered. Some are counterbored to something like 20mm so I guess the Mazda location uses tubular "dowels" and bigger bolts. I shall turn some sleeves to bring these down so I can use 3/8 UNF bolts to match the car. I am fortunate to have a nephew who repairs farm machinery and carries a good stock of bolts, set screws and Allen screws in metric and imperial, so I have already collected what I need. I also needed longer 5/16 UNF setscrews to accommodate my 6mm spacer plate. Thanks David for the weight. Mine weighs in at 15 lbs 14 oz but this is with the starter ring. Any idea what the ringear weighs? Thanks Alan, that could certainly be the way to go particularly if you do have the benefit of a lathe as I do. If the price is right would just be an easier option anyway. cheers again John |
| j c macleod |
| Nigel Standard 948 and 1098 flywheels are heavier than the 1275 version, as they are flat-backed. No actual figures, though. |
| Dave O'Neill 2 |
| Yeah , big bolt holes in the bellhousing but the 4 main securing bolts on a Mazda are 12mm They'll never grab in the holes that's for sure- and large cylindrical dowels as you say- |
| William Revit |
| HI Willy, thanks for your feedback. I am over in NZ for on holiday later this year. Do you ever get over there as only a small hop for you. HaHa! Could hook up if so. CORRECTION: My previous post should obviously said " if you do NOT have the benefit of a lathe as I do." cheers, John |
| j c macleod |
| Thanks Dave, I thought that might be the case (but don't know why I thought so). |
| Nigel Atkins |
| John There is a ditch between here and there, I've never tried to get accross it-- Seriously though, if you are going to Auckland you ought to try and get in to meet up with Paul Walbrum at Paul Walbbrum Motors He'd be interested in what you're up to, I'm sure, and have plenty of tricks and toys to show you willy |
| William Revit |
| to make any contact easier, it's Walbran http://mgparts.co.nz/ |
| David Smith |
| Ha ha -David Had a big day on the road yesterday, bit tired at the time of writing---hence two wrong choices at the spelling Sorry Paul |
| William Revit |
| When is the next instalment due? |
| Alan Anstead |
| Hi Alan.
Watch this space. I have got the engine and box together. I have cut and welded the body/chassis. I.e. openned up the propshaft tunnel and tubed and boxed the cross member to take a bridge piece. Also modified the heater plenum to give more bell Housing room. This may not be 100% necessary but will report on installation. Gearstick installed, speedo drive plugged up for now, starter motor in. Obviously flywheel and clutch h assembly installed, all good on clearance. Next step is to try dropping the lot into the shell! Hopefully this weekend. Only then need to make up crossmember to support gbox, easy enough, and to adapt propshaft, less easy. Tempted to use Mazda prop because it would shorten easily without messing up the balance. I think I can bore out the Mazda differential yoke by 1mm to accept the MG universal joint spider. Going the other way would present greater balancing issues. I can try this and still leave the other option open as not cutting those bits up. Will post some more pics in next installment. This one shows heater plenum mod before grinding up welds, looks quite good now. 
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| j c macleod |
| Thanks for the info, I hope you are keeping your drawings up to date as I imagine quite a lot of us would be interested in following this route. |
| AdrianR |
| Hi Chaps,
the engine is IN! (after a bit of fettling) . I knew that the clutch slave may be an issue and sure enough it just fouls the chassis rail. Even though I have the massive advantage of a 4-post lift with recently aquired wheel-free jack as well as an engine hoist, working by myself was a bit of a struggle to get things to line up so I was releuctant to pull it out again to make further g/box mods. Actually I found my error was not to release the engine mounting brackets, relying instead on the rubber mount bolts to re-align. The brackets are designed to allow the engine to drop straight down with rubbers already installed and it became much easier once I did this. (simply my laziness before) To avoid removing the assy again, after long deliberation, I opted to chop and strengthen the chassis rail to provide the clearance. Others may opt for a concentric slave or it may be possible to reduce the height of the lower slave mounting bolt which may make enough room. You could even move the slave to the other side of the box (release arm pivot relocation not-withstanding) where there is more room, or simply shift it up a bit, but access is poor with the starter motor in the way. However, if the mod I have made were done when the engine is not in the way it would only take about an hour and I can't think that I have compromised anything substantially, if at all. I have had to make a bit more room in the transmission tunnel above the tail shaft, specifically to accommodate the two rear gearstick mounting bolts. This was necessary to allow the g/box level to be correct. Again, not wanting to take it all out again I found a rather nifty way of swelling the tunnel (Refer to early comment from William!). I recently purchased an air chisel for the first time from Lidl (£15) and have found it quite effective for splitting metal. I decided to sacrifice a simple pointed tool (for making holes?) by cutting the end off and shaping with a grinder to accept 3/8 socket extension bars. By using a long extension on the modified tool I could reach up beside the tail shaft and thump hell out of the tunnel (to the point of splitting it!) sounds brutal but was actually rather effective. I had already needed to split the gearstick hole in the tunnel to allow a bit more room for the Mazda gearshifter. This will need a little remedial attention but should still take the MG boot. If one were to allow the gearshift to be as far forward as possible (as per my original faux-pas) then this would not be necessary. I shall eventually report on gearstick position/feel but looks spot on at the moment. I am currently determining how best to support the g/box, but using one of the original MG rubbers looks to be ideal. I just have to decide whether to make up a spacer block and crossmember to use the Mazda rear 8mm bolt holes or to drill and tap a 9/16 UNF hole in the g/box side-rail lump (most of which I have chopped off to make room ) to fix the MG mount into. Given I always intended to reform the chopped crossmember for chassis strength, having tubed and shut the chassis rail already, the latter idea seems obvious but the rubber mount would be several inches further back and thus need further support from the floorpan to stop it twisting down. A simple bolt either side with large area washer or a small load spreading strap would suffice. The former method would require similar support from the floorpan using a couple of load spreading straps located down beside the seats through the floor and thus bolting a 1/4 steel plate across the tunnel below the tailshaft. I have already cut a length of square spacer tube before reviwing the front crossmeber method and so I think because this will make the front crossmember a very simple 10mm thick x 50mm wide x 200mm long strap with 2 9/16" holes in, I may go for the additional rear crossmember. It has the added merit of additional chassis strengthening, having cut the tunnel floor out for access, which is a great boon I should say I have purchased a 15/16 inch reamer from the glorious ebay for £20 with which to ream out the mazda propshaft yoke. I have cut off the iff end of the Mazda prop and ground and hand filed to a lovely dead square simply by following a very convenient machined shoulder. I have determined that simply by reaming the mazda yoke out by 1.3mm (which still leaves it with more "meat" than the MG yoke) I can simply mate the Mazda propshaft to the MG differentail yoke using a new UJ. I shall need to carefully determine the centre which I can do easily on my lathe, and then dremel circlip grooves which the Mazda does not use. I shall then simply cut the Mazda prop tube to the required length (approx 23") and cut it off square by the simply wrapping a sheet of A4 around it straight to give me a dead square datum. Then carefully weld the yoke back on. I feel pretty confident that this should not mess up the balance too much, but it is easily removed later if I am not happy with it. I hope this is more interesting than confusing or boring and hope to see it move by next weekend, all things being well. I attach one pic of the chassis chop for the slave cyclinder prior to tidying with a sander. Note I achieved this with the engine simply lifted 6 inches, thus making it hard for myself. If a profrssional company were making a kit they would probably go down the concentric path. I have yet to see if the Mazda slave will operate sufficiently well from the MG master. Time will tell. I shall post completed pictures in due course. best regards, John 
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| j c macleod |
| Hi All,
see image below of gearbox in place and supporting crossmembers. the forward one is only for body rigidity, the rear one is supporting the gearbox tailshaft. I will send more details pics following on. I have reviewed the propshaft modification and decided to go with modified Mazda differential flange because this is easier to follow and also can go the MG route after if not happy. if I wnet the MG route first I have no second chance. Note the pic shows the Mazda spider in place but only in the diff yoke, I have already broken the shaft yoke spider bearings and now must replace the spider, not easy as it is "staked2 rather than circlips. There was no need to break it though you would not easily be able to lathe it up nicely like mine then, though this is not actualy necessary. The clutch slave is in and working, looks OK but will need to drive to prove 100%. I used the MG flexible by simply tapping a brake tube nut joiner to 5/16 NPT on one end to accept the flexible thread, then made up a short 6inch joiner pipe with tube nuts both ends to connect to the slave cyclinder. You could use the Mazda pipe if you have it but it is 2 feet long. I am desperately trying to complete this weekend to try it before we depart to the Antipodes for 6 weeks. I will be very frustrated if I dont know if is going to work for all that time. (Though perhaps it may be better not to no if id doesn't!) Must sign off now, will attach some pics as a "taster". Cheers, John 
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| j c macleod |
| Crossmeber pic before floor holes drilled. I have used 5/16 UNF High tensile bolts with some spreader pieces inside the seats. Pics another day. In hindsight I could have gone to 3/8 or 8mm but this will be OK I'm sure. The rubber is one MG mount which has a 3/8 UNF stud on the bottom bolted into the box. John 
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| j c macleod |
| modified Mazda UJ, spider needs replacng and then welding to teh shortened prop tube. chhers, John 
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| j c macleod |
| Hi All.
IT WORKS!!! Does this make me the first person to put an MX5 box into a midget IN THE WORLD! I have finally completed the installation this evening and test driven about one mile. It feels good in this short test except I need to adjust the gearstick mechanism because it is very notchy at present where I have had it apart but the box sounds quiet and everything smooth at the low speed I was doing. I am now off for a few weeks holiday so play will stop so I was desperate to just see it work. Maybe I can update the tech file whilst we travel. Cheers for now. John |
| j c macleod |
| Yay--Congrats.----enjoy your holiday John--Is this the NZ trip Cheers willy |
| William Revit |
| Well done John. I might be wrong but I think I saw somewhere someone putting something about a MX-5 box in a Spridget somewhere (possibly UK) - but can't remember where so perhaps I imagined it. I think yours is the first in this world! |
| Nigel Atkins |
| Nigel You weren’t dreaming 😀 There was a Frogeye at the Ace last week, as seen in the ‘general’ thread entitled “Ace Cafe Tuesday 12th Feb”, with a Mazda gearbox. |
| Dave O'Neill 2 |
| It was me, I met a guy last week who had a Mazda box in his frog eye It looked very neat. He didn't know what kind of Mazda box it was and neither did I. The car came like that. Its fitted to a 948 a series engine. I posted some images on one of the other threads Ace cafe thread |
| G Lazarus |
| My mistake, its here https://mg-cars.org.uk/cgi-bin/or17?runprog=mgbbs&mode=thread&access=&subject=110&source=T&thread=2019012516322620457 |
| G Lazarus |
| On the "looking for the one" thread on the general page. |
| G Lazarus |
| Yes, of course, so recent yet I forgot. I don't know whether to be pleased that at least I remembered it vaguely or worried as I forgot something so recent. I'll be worried for now as I know I'll soon forget about worrying what it was I was worrying about. |
| Nigel Atkins |
| John, you keep the title of first MX-5 box'd Midget in this world at least. Oh, and thanks Dave and Gary for reminding me about the Sprite. |
| Nigel Atkins |
| Thanks lads,
It was quite a thrill to finally drive it up the road, in the dark, with no bonnet fitted. Sounding quite nice actually without a gearstick boot in place. I only got up to about 30mph as it's a narrow lane and wanting to check it all is looking OK before a proper blast. The gear change mechanism is quite a complex device compared to an MG, Triumph, Ford system with springs and plungers keeping the stick in line. I have disturbed this and need to adjust it, possibly adding another bracing link to make it more rigid. I was tempted to do so before installing but thought I would give a try first. I see the update just come in making me the second IN THE WORLD. But never mind. I could not find anyone else when I set out and plan to post how I did it for others to copy of they wish. In the end I achieved with only garage tools plus my lathe but it only requires 2 spacers, one for the spigot and one for the diff flange as I actually stayed with the Mazda one, and some reducers for the bell housing bolts. All of these could be done by hand if desperate. Can't upload a picture as are in Whatsapp and can't get one out.😠 And yes Willy, we fly for New Zealand tomorrow.😁 Cheers all, I will be watching and will pick it up ASAP. |
| j c macleod |
| Well done John you had all the same brain waves as I had, I've fitted the mx5 box to a austin maestro 1.3 engine in an austin A30, but not quite running yet. You're No 1 midget mazda man. Have a good holiday |
| A Gregory |
| Hello All,
I have finally returned from a fantastic Big 6-0 holiday in New Zealand all refreshed and eager to go, jetlag not withstanding! So today I have driven the car for the second time, this time about 10 miles whilst getting some fuel, with the following to report. Good points: the gearing is great with 5th overdive being a fantastic improvement. The clutch works perfectly and has kept its fluid aftr 6 weeks! There are no nasty vibrations from the clutch or propshaft even at higher speeds. (no speedo at present but 4000 in top must be about 75-80mph). Poor point: Whilst I was doing all the modifications I noted, even before touching anything, that the gearchange was jolly stiff with considerable difficulty in engaging the gears. I assumed that this was a function of having no oil in the gbox, having been stood for some months and also no turning of the gears and had to trust that this would resolve itself. I reported that the gearchange was very notchy in my first very short drive. On this drive initially the change was notchy but usable for 1,2,3,4, R but 5th very difficult to get. After fueling and setting off again I could not engage 5th at all so stopped and managed to do so after considerable force. Unfortunately from that time on I can only notchily engage 2,4,R with 1st only after going into 2nd. I have tried releasing the fixing bolts of the gearshift and moving it in different ways hoping to find a sweet spot but unsuccessfully. I have read many threads from MX forums regarding stiff or notchy gearchange, the most common answer being change the oil to thinner type and replace oil in the gearstick turret. I have filled the turret and the gbox was filled with thin oil anyway. These fixes must relate to friction issues in the selection mechanism. I am thinking that there must be some issue like a burr or rust in the selector rods. When I was doing the mods I split the box because I had let the selector rod drop out of engagement and wanted to be sure it was properly re-engaged. It does not seem that it can be wrong once it is back into place but is best to stop it coming out in the first place. ANYWAY. before I have to take the box out to sort this does anyone (perhaps William) have MX5 gbox experience to help.? Cheers all. John |
| j c macleod |
| John,
welcome back. As with the Ford T9 box many have found using Castrol Syntrans Multivehicle 75W-90 Fully Synthetic MTF (which is to GL4 spec) helps gear shifts particularly in cold weather - but it sounds like it might only help a bit in your case but worth using regardless. Thorough oil changes done with oil hot and left to drain as long as possible to help get out as much existing oil, muck and crud are always worth doing. It also gives an opportunity to inspect the state of the oil and anything else that comes out of the box. I'd normally suggest using the existing oil as a rolling flush for around 100-500 miles at least but perhaps a change right now might help and perhaps provide some answer. https://www.opieoils.co.uk/p-739-castrol-syntrans-multivehicle-75w-90-fully-synthetic-car-gearbox-oil.aspx 
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| Nigel Atkins |
| Hi John
Hope the holiday went well--some sad news from over there lately with that idiot gunman on the loose. First off- can you select gears ok with the engine not going If you can get them without the engine going it's a clutch issue If it's still stiff without the engine going it's going to be a selector issue The most likely offender would be that switch up on the top rh side of the housing where the selector shaft goes in-these are well known for breaking up inside and jamming up If you unscrew the switch out a few turns and the gearchange miraculously loosens up then this switch is the cause of your problem willy |
| William Revit |
| Hello both,
thank-you for your best wishes, yes indeed Willy we had a good holiday and were in Christchurch only 3 weeks before the horrific attack, so all very real. Terrible for the everyone in NZ, they dont know what has hit them. Regarding the gbox, it will not select 3 or 5 gears when engine stopped or running and 1 very reluctantly. Clutch working very well. The box has new Generic TradeTEC "75W-90ss GL5 & GL4 semi synthetic gear lubricant" in from the local auto parts shop, i.e. nothing special! Purchased before reading the MX5 foums about tight gearchange issues. My own feeling is that it is selector related BUT your idea regarding the switch is a very good one to be checked tomorrow. If no joy then I shall try the better oil. I realise now that perhaps the trickiest part of the whole excersize is getting the gear mechanism right. There is limited scope for the fixing of the turret after cutting it back and I would: A)Do it differently next time, retaining the forward 2 turret bolt holes, causing the stick to be very slightly further back than the MG position & B)do so with greater care to precision, i.e. probably get something machined on a miller to be positioned exactly and incorporate a dowel(s). However I feel I must be able to make my home-brew system work with a bit more fettling. I will keep you posted. Cheers, John |
| j c macleod |
| The TradeTEC 75W-90 SS GL5 & GL4 will be fine (for now at least) as your problem seems very much (not that I'd know just echoing) 'front gears' selection and switch.
But for next winter or the winter after as a comparison (or if you want to see if any bits come out of the box perhaps sooner) I'd still suggest a switch to the Castrol Syntrans Multivehicle 75W-90 Fully Synthetic MTF as many owners find it so good. Personally I use Millers CRX 75w-90 NT+ in my T9 box as I doin't live in the colder parts of the land. |
| Nigel Atkins |
| Nlgel
Yes there are issues with oil for T9 boxes but usually it's just a general jam up baulking feeling when dead cold and as they warm up all comes good-the multi grade synthetic oil is the fix for that but John's issue is mechanical as he has changed it's characteristics by giving the lever a big tug It's either going to be a jammed up switch (fingers crossed for that) or an aligment issue with that shortened main selector shaft as that is the only shaft that operates all gears--If it were an issue with one of the shafts further into the box ,then the problem would only be with the pair of gears moved by that shaft like 1-2 , 3-4 , etc |
| William Revit |
| Hi All. Just a quick update. Removed top switch and quite a bit easier to move so further points to mechanical alignment issue. Then I tried applying a big spanner to the turret to allow me to twist it, showed promise. So I rigged up a jacking screw by welding a nut to my bracket and winding a screw down against a web on the side of the box to twist the turret to the right. I can now select all gears with some effort whilst static. When driving I can select 1234 reasonably well but not 5th, no matter how I tweak the jacking screw.
So useful progress indicating that the gear change mechanism is super sensitive. I think I have not quite re-drilled the shaft in its original line so causing grief. Options are to remove engine and box, possibly connect to clutch remotely and even run the engine on the floor, to allow me to rework the turret fixing but I think I might just cut a reasonably large piece out of the tunnel to allow me to fix it in situ then weld it back on after. I have already got some repairs to do anyway. Ideally I would start with a new gear change mechanism but will see how it goes. Cheers, John |
| j c macleod |
| Willy, I was agreeing with you, Castrol for winter use this year or next perhaps. John. my T9 remote was shortened just out of alignment (at no extra charge which was good of them) so my 5th is a very notchy change with a worn gear lever and impossible on a gear lever with a taught mechanism, car static or moving. |
| Nigel Atkins |
| John, my son had an MX5 with a notchy gearbox, especially when cold. Fully synthetic oil was the solution, it improved the change dramatically, so when you have your change issues sorted it may be worthwhile filling it with a couple of litres of fully synthetic? Here's a link http://www.mx5parts.co.uk/gearbox-manual-fully-synthetic-models-p-1591.html Apologies Nigel if I'm duplicating your post/advice only wasn't sure if your oil was fully synthetic :) 
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| Jeremy MkIII |
| Jeremy,
don't be too concerned about the description of synthetic, without going into it the term is often used more of a marketing tool than totally accurate description, a good oil is a good oil - and Mobilube are Castrol are good oils AFAIK. If you really must look here's a Wikki - https://en.wikipedia.org/wiki/Synthetic_oil I've used and recommended Mobilube before - but they withdrew the use recommodation for T9 boxes (might have restored it now?) so if the gearbox was recommended for GL4 I no longer usually put it up despite myself using GL5 oils, changing beliefs is difficult. MX-5 owners I thought went more with the Castrol (which is GL4 and described as fully synthetic) and I know myself and others with T9 and MX-5 boxes have found the Castrol particularly good for cold weather gear changes. As you know I now use Millers CRX NT which again is described as fully synthetic but all three are good oils from what I can tell of my use (other good oils are available). :) Just changing to fresh oil can sometimes help with some issues on some cars especially when you think an MX-5 could be up to nearly 30 years old now and like many MGs the gear and diff oils in them could also be "vintage" (or very ancient I bet in some MGs, classic car owners are known for their palm grip strength). |
| Nigel Atkins |
| "classic car owners are known for their palm grip strength" what are you trying to say there Nigel.......? |
| C MADGE |
| Tight-fisted - over careful with their monetary expenditure, white knuckles from gripping their cash. What did you think I meant . . . |
| Nigel Atkins |
| Hello All.
Thank-you for your ongoing inputs, all very useful. My latest development this evening has been to remove the side cover of the MX5 gearstick turret in the hope of adjusting the action block angle on the selector shaft. Not easy in situ so not altered yet but what it did do was to make the whole turret far less rigid allowing a lot of flexing whilst changing gear. Rather against the design principle this actually allows me to select ALL gears! OK, not great but enabled me to test drive the car again. Whilst the action would not be at all acceptable for general use it did allow me to prove that the hybrid MG/MX clutch centre-plate and MG master/MX slave works sytem absolutely perfectly. Also the gear ratios feel great with 5th doing just what it should, and no vibrations, all enthusing me further to press on. What I believe this tells me is that 1. The issue is external and should be fixable and that I have do not seem to have damaged the selector mechanism. 2. The internal design of the selector mechanism is very particular. I suspect that this is mostly due to the detant components. One might have thought that there must be some modification which could be made to the mechanism to overcome all these problems but that would require the box out :( In the light of this I shall review my turret fixing, possibly sourcing a new turret assembly to start afresh. cheers, John |
| j c macleod |
| Wouldn't surprise me if Mazda's engineers went to a lot of trouble to get the right feel on the gearchange, they were trying to build a car that felt like a sportscar and having a slick rifle-bolt type action rather than a porridge stirrer could well have been a key design goal.
My recall of driving an MX-5 (5 speed version on road trip to and then around Castle Combe circuit) were that it was quite revvy at road speeds compared to my S1 Elise so interesting that the ratios suit the MG well. If you're treating your car as a development mule then cutting the top off the trans tunnel makes sense, you can then adjust in-situ and as you say weld up again when you are happy. |
| AdrianR |
| Mazda went to a great deal of trouble to get the MX-5 to feel and sound right, without the MX-5 budget(ish) two seater soft tops probably wouldn't have continued.
The gear shift on the Mk1s and 2s that I drove were lovely rifle bolt short shifts, more precise and shorter but same lovely feel as a Spridget (on 2nd to 4th) box in very good condition. John, it's great that you been able to drive and prove your clutch/flywheel, if you can you want to keep the sweet gear shifting with whatever you're doing with the turret. |
| Nigel Atkins |
| John, as l recall, you shortened the gearshift extension, moving it forwards so that the rear pair of bolt holes on the extension were then bolted through the forward pair of fixings on the main casing. I may have this wrong as I wasn't paying close attention.
Are you sure that the 4 bolt points on the main casing were in exact alignment - in the same plane - and that plain parallel to the selector shaft? Any slight discrepancy would translate to a sideways thrust on the shaft. Perhaps slacken the mounting bolts, and if that eases things then experimenting with some shim might improve the alignment? |
| GuyW |
| Evening Lads,
..............I'VE CRACKED IT !!!!!!!!!!!!! finally:) The action is now near perfect, a very slight "nick" into second which I may be able to adjust out but don't want to risk losing what I have just for the moment as all other gears are very sweet. TBH it may be this box was like this before as I never drove it. Anyhow it is pretty darn good. Now with the side cover off, close inspection of what was happening revealed a somewhat surprising action. Whereas I imagined that the "ball end" of the gearstick in its little plastic bucket would provide a very good linear translation to the selector shaft, there is in fact a very considerable amount of lifting motion as the gearstick travels though its arc. Because of the "close coupled" shaft mountingd, this subsequently causes two problems: 1. it is amazing how quickly this siezes the shaft in the turret wall because of the jamming effect. 2. it obviously causes considerable erronious movement. i.e. vertical translation of the selector "fingertip" hence the horrible action. Therefore I stood back to review and looking around the garage found a very nice piece of 3/4 inch thick tool grade aluminium from an old job I had worked on a few years ago. I therefore set about it using my engineering apprenticeship training of 43 years ago to do a "proper job" as we say down here in Cornwall. See attached photo for final result but I will briefly outline my procedure and will provide full details in due course, dimensions, etc. First I hacksawed a piece off which due to holes etc in the stock was 130mm X 39mm X 3/4inch by default. Others would be OK with 20mm material. I then carefully filed it square, flat and true as my old apprenticeship tutor would have had me do. It was actually pretty darn good. This would be achieved on a miller in miutes but took me about an hour. I then created a flat datum by carefully removing metal from the gbox casing under the selector shaft where it enters the casing. I decided to use the obvious datum of the differential "girder" fixing bracket. I assume that this must be a good standard for all gearboxes as must be repeatable, surely? In actual fact this proves to be slightly too low as it just breaks through the casing! In future one would use perhaps 2mm above this datum and use a 2mm spacer to fill the gap. this was done by hand with a file to finish but the greater amount was removed with a 1inch wood chisel and hammer! I then determined the exact centre of the selector using a vernier and drilled a 14mm hole though it at the required height. I used a pillar drill to ensure it was exactly perpendicular.I could then offer up the piece into place and fettle the datum until it slipped into place nicely. In fact due to the aforementioned break through, I had stopped filing so not to make the hole any bigger so i actually relieved a very small amount from the bottom of the cross-bar. I then determined where to drill the cross-bar fixing bolt holes. One 8mm tapped hole was already determined as I had already drilled it for the first attempt so I had to carefully determine where to drill the matching hole in the cross-bar. There is no really good pick up point on the left side of the box so I drilled a 6mm tapped hole in the now "decked" gbox strengthening rib. This actually breaks through into the box but there is plenty of clearance inside. I drilled these on pillar drill to ensure exactly perpendicular. I then further flattened the face of the turret where I had already cut off the mounting bracket so that the cross-bar sits perfectly flat on it. I could use the offcut from the selector shaft removed "way back when" as a dummy to align the cross-bar on the turret so that I could determine where best to drill and tap 4off 6mm holes in the end of the turret to fix it to the cross-bar. (dimensions to follow when I bring this all together). I then very carefully used marked the drilling positions onto the cross-bar and drilled through AT TAPPING SIZE (5mm) so that I could then carefully postion and clamp together in a bench vice the cross-bar on the turret using the dummy shaft and an engineering square to make sure it was all square. Then use the cross-bar as a guide to drill though at 5mm into the turret, thus ensuring exact alignment and square-ness. Then drill the cross-bar out to 6mm on the pillar drill after using the 5mm drill to re-align each hole before drilling. This made sure it all came together perfectly. This would be the preferred method of drilling the gbox to fix the cross-bar but I already had one tapped hole to work with. In the event I had to ease the drilled hole with a file to get the 8mm bolt to catch, always the tricky part. I did do this for the 6mm hole Then screw the two together with 6mm allen screws. It is necessary to Dremel away alittle of the gbox casing selector rod entry to allow a little clearance for the allen screw head. You could use countersunk screws but I preffered the extra head. Counntersunk would be a good option. I then slid the assembly onto the sector shaft and it went into place beautifully. I had already drilled and tapped a 6mm hole in the gear stick selector shaft pickup block for a clamping screw for the previous attempt so this enabled me to assemble the turret and the find the sweet spot for the gear change action with the intent of drilling and roll-pinning when happy. In the event, because this new fixing is some 6mm or so further back the shaft is already slightly shorter than I would like and when I fully tightened it it "spat the shaft out" because it was just catching the end. Therefore I drilled the original roll pin hole out to 6.8mm and tapped at 3/8 UNF because the thread is finer than 8mm metric and therefore gives better strength in the relatively short thread. Having found the sweet spot I tightened as hard as I dare and test drove with brilliant result even without the spring centreing action yet. On return I then assembled the turret side cover with its spring loaded plunger. Tthis required a little removal of some metal from a boss on the gearbox to allow the cover to sit down properly and a little from inside the turret cover to allow some clearance for my bolt head. I still need to cross-dill for the roll-pin but will drive it for a few miles before committing. I have used some rather sticky food grade grease that I have instead of oil to lubricate and this is working fine. I arther think that all this business about changing the turret oil in MX5s is actually really still a problem with the shaft jamming due to the arc lifting moment. It may be that a nylon push in the crossbar would be good feature but mine is fine at present. Maybe a grease nipple onto the shaft would be a good idea in case it tends to sieze over time. Anyway, apologies for the verbal diahorea. Hopefully it makes sense and when I have properly proven it all I will create a file of the entire method. Any suggestins how this should be "published"? Is there a better method than in a BBs thread to do this on this forum? Thanks again lads for all your interest, Cheers, John |
| j c macleod |
| Sorry, original pic was too big to send so here it is in another format. Another late night! John 
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| j c macleod |
| Ahh -very good
So if I understand this correctly' Because the selector has been significantly shortened, the selector shaft was rising at an angle and jamming-whereas in it's longer original form the angle would have been less and not a problem-- good find I had thought earlier it would have been easier to leave all that part std. and fit a gearlever adapter ,but then there's the issue of having a bump in the floor behind the new lever which can get in the way They're good for moving a lever back'ds but not so good frd. willy |
| William Revit |
| Hi Willy,
first response to update being middle of the night for you! Yes you have got it right, the combination of jamming effect and upsetting the selector finger positioning ruins the change. My 3/4 inch "cross-bar" bracket provides enough linear support of the shaft to provide excellent control of the "waggle". If this system were to be productionised it might be a good idea to incorporate a bronze or plastic push to ensure that it does not sieze due to oxidizing, etc. This will be proven with time. If I do another one (as already requested!) I might well let the selector shaft continue through the back of the turret housing as had been my original intent as this would be useful for adjustment purposes. By using grease instead of oil as the lubricant it would hardly need a seal or would be easy enough to seal sufficiently with an O ring, lip seal, leather , felt, device, etc. Having reviewed the new method I believe that this method is actually as good as any other and is achievble with only hand tools and a pillar drill. If I repeat the excercize I think it would take abot 4 hours to achieve the gearchange mods in the light of experience. Now need to repair the tunnel but intend to allow a panel for future access and then sort the speedo, currently using satnav as speedo. Top gear appears to about 17.5-18 mph/1000 rpm ie, 70mph @4000 RPM so very comfortable cruising. Been for a longer drive with my daughter driving today and she had no problems with gearchange at all and a fairly light clutch pedal, so that has to be success.The benifit of synchro into 1st is considerable, especially if you do not know how to double-declutch for a novice driver. On the wider project I would probably advocate others using the Mazda clutch plate assembly on a machined flywheel, taking the weight penalty, possibly compensating with a bit of engine tuning. This would make clutch replacement straight forward and the larger clutch plate would probably never be worn out anyway. This would also be easily accomplished by a machine shop since it is 2 simple machining processes of lathing the flywheel flat and lightening where possible plus simple drilling and tapping 6 holes to take the cover plate. Less complicated than making a hybrid clutch plate as I did. I will document this fully when I have done a few miles to build confidence. attached view of turret and cross-bar drilling method. cheers, John 
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| j c macleod |
| All good John It's only 2-15 the night is only starting Doing an allnighter tonight Clutch in an Iveco motorhome that's booked to go on the boat tomorrow I feel so lucky to be given the chance to do this-------------honestly, well, maybe not back into it now willy |
| William Revit |
| John, are you sure about your speed and revs, IIRC 4th gear direct with standard Midget box, wheels and tyres is about 16.5mph per 1,000rpm, so about 4,250rpm for 70mph. So I'd have though about 19.5/1,000 for 5th gear (if all else standard) about 3,590rpm for 70mph. Or have I, as I often do, missed something. |
| Nigel Atkins |
| Hi Nigel. I have just been on a test drive with my son and checked the speed/1000 as 72 mph at indicated 4000 rpm. I need to verify the taco calibration which I can do with my optical taco shortly. I am getting the mph from a TomTom satnav so should be reliable. Will report back. Cheers, John |
| j c macleod |
| John, I enjoy eating tacos, a nice Mexican treat, but wouldn't know how to calibrate one, optical examination limited to correct assembly. I wouldn't try eating a tacho(meter) though. |
| David Billington |
| That does sound about right John
Do you know what ratio final drive is in your car Doesn't really matter though, if it feels good it feels good Doesn't help much but a std 5 speed MX5 sits about the thickness of the needle under 3400 at 110 KPh (68mph) so at 70 mph it would be just about bang on 3400 But- that's a 1600 -4.1 ratio but taller tyres/wheels(185/60/14) than a Midget and Mazda speedo's are a tiddle fast anyway so could even be around 3500 with a sat. so your 4000 would be fairly nice I would think with the smaller engine willy |
| William Revit |
missing pic...crossbar drilling method
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| j c macleod |
| Hi All.
Not so keen on Mexican myself Dave, more of a pasty man down here in Cornwall :) Thanks for the feedback Willy. I have just now come in at 00:15 from a spirited 15 mile drive to & back from a friends and can confirm that it is working sweetly. Gears selectors seem to be bedding in and change is almost perfect. As you say the gearing with the smaller engine is about right. She cruises nicely at 3000-3500 in top (5th) but does not have the guts to accelerate from there with any gusto but drop it back to 4th or 3rd and get the revs up then she will pull 5th at 4500 as I tested or more on a better road. I think 80mph cruising on the dual carriage-way would be OK if still a bit revvy, 75mph will be comfortable cruising, which in a low open top feels rather more than a in a comfortable saloon with modern sound proofing and suround sound radio! If 5500 where achievable it would be 99mph, maybe downhill with big cajonas! Not a problem in the TR6. I took the TR for a spin yesterday after a 6 week break and thought "YES this is nice", plenty of real torquey umph, but do you know, my son and I (who has an MGBGT) both love the Midget for shear fun at sensible speed. It just makes us smile and all the more so with a sweet gearbox. The attached picture is if my INITIAL gearbox drilling. NOTE THE LEFT HOLE HAS BEEN SUPERCEDED by a smaller 6mm tapped hole in the web further out. I chose here initially to allow for an 8mm bolt to give good rigidity but when I determined where to drill the turret I realised that this hole was right in line with the "meat" of the turret where it would be best to drill and tap and also maintain as wide a fixings as possible to give horizontal rigidity. Hence you will note the spare hole in the cross-bar. i should plug this with mastic as it would potentially allow water into the gearbox. 
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| j c macleod |
| John,
I'm a bit lost, if the engine and its necessities are in as good a condition as it could or should be and set up well then I'd expect a bit more from it but it's all a matter of perception too. Obviously it hasn't the torque of your TR6 and 5th gear is for cruising but with a pretty standard engine at 3-3,500 revs I'd expect at least the start of some reasonable but very unspectacular pick up in 5th unless going uphill as you'd be on torque and in power band. '71 Midget as standard would have 3.9 diff, 4.5" rim Rostyle wheels, 145/80r13 tyres so with 5th gear at say around 0.81 then 3,500rpm is say 70mph, for very round figures and allowing for speedo and rev counter errors, and 4,000rpm is about 80mph for round figures. |
| Nigel Atkins |
| Hi Nigel,
actually after a little further driving I find that she does pick up reasonably from 3000, I am on a standard 3.9 diff because I had already purchased 3.77 diff to help the cruising rpm before the clutch went. I still have this and will sell it again when I am happy I do not want to use it as well though I fear that may have too much impact on acceleration. Though sometimes I find that what you lose in outright acceleration in first you regain by not having to change up so soon. I am indicating 70 at 4000 so 17.5/1000 which would be 87.5 at 5000 or 4571 for 80 mph, so quite acceptable compared to standard. The more Idrive it, the more fun it becomes, those who have tried it are really complimentary so I am well pleased with my efforts. I now just need to repair the tunnel and sort the speedo. As promised I will write this all up soon but how should I publish this, does the forum have a better method than in the BBS. Cheers, John |
| j c macleod |
| PING---200 posts the car moves and the job is nearly done fantastic |
| William Revit |
| John,
I'd check your rev counter for accuracy, otherwise what ratio is 5th on your box, I was guessing it'd be about 0.81 or 0.82. I drove for years on my rev counter so I know the speeds on my T9 4th and 5th gears particularly well, as I didn't have the speedo recalibrated until recently (it was 25%/33% out, depending which way you calculated, showed 30mph at road speed of 40mph). As I put I'm on a 5th gear of 0.82, 3.9 diff, 145/80r13 tyres and show about 3,600rpm for 70mph and 4,100rpm for 80mph, I put about as I know my rev counter is around 100rpm to 200rpm out at various points of reading from a previous rolling road session where it was noted. For the sake of keeping under speed limits in 5th I just double rpm for mph. There might be a bit of rounding off in this calculator I think but it gives the idea (and agrees with my rough figures). - http://www.fisc-racing.com/misc/ratios.html |
| Nigel Atkins |
| Hi Nigel,
I have just been out and checked the rev counter using my optical tachometer and this indicates a +200 rpm error, i.e actual 2000 reads 2200, 3000 reads 3200 and 4000 reads 4200. Was difficult to go any higher as doing this by myself. Therefore this modifies my numbers to 70mph @ 3800 rpm = 18.42mph/1000. However you make me doubt my sanity so I will check my raod speed again tomorrow using the satnav. I assume a satnav cannot be signifcantly out or else the system would surely not function correctly. According the the net 5th in an MX5 is 0.814:1. FYI the optical tacho I use came from ebay for £10 new and is a great little item I use regularly in my work, thoroughly recommended. See image below. Just search optical tachomter on ebay if interested, several sellers of the same item. cheers, John 
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| j c macleod |
| Hi John,
a proper SatNav I forget the refresh rate but it's good enough - however SatNav or road speed phone/mobile-device "apps", particularly free ones, can be a lot out - mobile phones seem to have gone back to the days of "Hello, can you hear me, hello . . . oh, he's gone again, ring back"! I think I've seen you recommend those optical tacho before. Are you sure your car's tacho is out 200 at every point, IIRC mine varied between 100 and 200 at various reading points on the gauge, not a fixed or linear error. And could your diff be a different ratio to standard and/or different sized wheels/tyres - or tyres inflated to something like 50 psi. :) As I put my figures are rough but enough difference to yours to suggest that the very small difference in 5th ratio (that's if the Ford isn't rounded up anyway) isn't the only difference in our cars' set ups. |
| Nigel Atkins |
| Hi Nigel, quick update.
been for a quick blast to ercheck the mph/rpm and with compensation for tacho error I have 60pmh TomTom satnav at 3000 (i.e. 3200 indicated) so your double the rpm is spot on for me. I checked the tacho at 2000,3000,4000 and found +200 at each point so could easily correct by pointer shifting if I want. I need to count the diff ratio again because my memory has failed but pretty sure it was "standard" when I checked months ago. Need to check tyre size as well. Next step is to repair the tunnel but I have had to repair my MIG welder first (sleeve in umbilical failed but replacement now fitted) On another front I have am awaiting delivery from Ebay of various bits to make a speedo drive system using as an proximity sensor, Arduiono microcontroller & drive card and stepper motor so watch this space in a little while. Should all cost less than £30 for prototype. This actualy more like my day job. I apprenticed as an instrument technician and progressed to electronics then PLC programming and have been self employed for nearly 30 years. For example, if you eat Yeo Valley Organic Yoghurt it was probably produced with my control system making 800+ tons /week. cheers for now. John |
| j c macleod |
| John,
it'll be interesting to see what your electronic kit comes up with as I'm now starting to doubt the calculator I linked to and whether I'm going the wrong with the correction of my tacho. But I know by just use that roughly double is near enough for a quick look. TomTom still going then, I remember using them and Garmin(?) many years ago when you had to wait for them to find 3, 5(?) satellites and showed you the coordinates of them before it would start to load up and sort things out. Of course it only went off, when it lost sufficient satellite signals, when you really needed it to find your way. At that time I think the mobile coverage had improved so when you rang back to base for them to look your route up (on AA Route Route planner, or was that later) by the time they'd got you directions the SatNav was back up again and they could hear it giving instructions in the background. My boss insisted we got used to these new systems instead of using paper atlases and our senses, usually a mix of both systems worked but ringing in now kept him happy that the less than 100% reliable SatNav was being used. Would have helped if he didn't keep getting skank copies of updates. I thought it'd be a good idea if they had the voice of your wife doing the navigation and chiding you when you missed instructions, wish I'd followed up on the idea. Yeap we've occasionally had yogurt from your control system. :) |
| Nigel Atkins |
This thread was discussed between 12/11/2018 and 24/04/2019
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