MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB GT V8 Factory Originals Technical - Follow-up on Costello Transmission

Several months ago I started a thread on the possibility of a 6-speed transmission from Ken Costello that was discussed at the Gatlinburg meet. On this thread someone mentioned that he may be working with a group out of Knoxville, Tn. Since I hadn't heard anything recently I contacted them directly and they informed me that they were not the ones working with Ken on this. Their unit which goes in Jag's they stated would be too large for the MGB. Does anyone have any additional information on if Ken is proceeding with this project?
Frank

I've not heard from Ken recently.
rick ingram

Toyota do a 6 speed and bell housings are readly availiable.
Peter

What model of Toyota and what is the source for the Toyota to 215 bellhousing? Do you have any web links to the adapter?

What are the internal gear ratios of the Toyota 6 speed?

What modifications to the tunnel (I already modified it for the Rover 5 speed)?

Richard
Richard Morris

Also, what kind of power will this toyo 6 speed handle? I am also quite interested.

Jim
Jim Blackwood

Frank,

Whomever you spoke to was mistaken. They were considering it, but decided that it would be a very limited market for a tranny that would cost about twice what a new Ford T-5 does. I think it would be a better, smoother shifting tranny, though. Also, it was a 5 speed, not 6.

Keisler does a 6 speed for the 67-69 Camaro that may be shoehorned into an MGB. They have an adapter that bolts it to the standard GM Muncie/T10/T-5 pattern. Should work with the stock Buick bellhousing. 5th & 6th are .8 & .62. I doubt any of us need or want a .5 6th gear.

I drove a Jag with the 6 speed comversion. Very short, crisp, precise throws, snick, snick, snick, snick, snick, snick. Still haunts me!
Carl Floyd

Carl,
I am at work so I don't have the original reply e-mail from Keisler to give you a name, but he was very interested in where I had heard this rumor. He was emphatic in stating that they were not working on this project. Again not trying to spread any misinformation, just like you trying to establish if indeed this is a possibility or not.
Frank

"He was emphatic in stating that they were not working on this project."

I'm sure that is accurate, since it's not going to happen. Ken did meet with them.
Carl Floyd

Don't know what Toyota models are available down under, but this is one possible source here in the US.
http://www.toyota.com/about/news/product/2004/08/10-1-pricing.html
Still would need to source the bellhousing adaptor.
Bill Young

May have to pay a visit to the toyo dealer.

Jim
Jim Blackwood

I know the answer to my own question, but, OTHER than the "Cool" factor, why would anyone want six gear ratios in a car with 250 plus ft/lbs of torque and only 2200 lbs?

As long as you had an overdrive in top gear, these things only need 3 speeds at the most.

Pete
Pete

Pete, with the sixth gear you can run a lower rear axle ratio and stil have good top speed and reasonable engine revs. I noticed that the Toyota pickup with the V6 and 6 speed runs a 4.10 rear, much lower than most found today. This would give good acceleration from a stop for a small engine with a relatively high weight and still allow good cruising. As far as needing one in a BV8, unless you're really needing fine gearing selection for racing such as autocross, then I agree it's mostly for the 'cool' factor.
Bill Young

Why not go for the BW T6 used in late camaros and corvettes? same bolt patern as T5 I think.
M Mallaby

Isn't the T6 box itself a little too large for the transmission tunnel? Just curious.
rick ingram

Rick's got it, the T6 is about twice the size as the T5 box. Not longer, but the case is huge.
Bill Young

Not the same bolt pattern. Requires an adapter. T56 is about 50-55lbs heavier than a T-5. Glen Towery made one fit a late model tunnel by grinding the case for clearance.
Carl Floyd

More T56 info:

http://www.drivetrain.com/gmt56inst.html
Carl Floyd

Very good info Carl. The Tremec adapter plate could easily be drilled and countersunk to the non-rotated pattern used on D&D bellhousings as it looks like there is plenty of beef and the old transmission could be used to mark the pattern straight up.

So the obvious question is, how much horsepower will the T56 handle? I think I've adequately demonstrated that a T-50 is inadequate for 300+ horsepower applications and it's specs are available for comparison in an old MGB-V8 article. If the T56's specs lie about midway between that and the T5 it should be OK. Crossmember fabrication shouldn't be a big deal, it appears slim enough to fit without much trouble, which leaves the shifter position. I really do need to get off my butt and take some measurements.

I like the fact that the Toyo 6 speed is used with a 4.10 gearset, means it would swap right into the stock MGB without an axle change. There's still the old issue with gearing up to gear down not being a logical way to pursue fuel economy, but still a step in the right direction. Wonder what the specs are with it?

Jim
Jim Blackwood

I procured a T-56 from a 2001 Firebird with 11k miles for use in large tunnel V-6 conversion. It was just too damn big and heavy. The one guy I talked to said he split hairs shoehorning his and then just uses 3 of the six gears, starting out in 2nd, etc. All in all just bofo for the job. Still on the shelf if anyone wants it.
vem myers

Jim
The T56 is OEM to Vette's and Dodge Viper's. It'll handle some horsepower! Draw back as Vern said, its big and heavy, but I dont think you'll break it!
The aftermarket T56 (for retro-fits in older cars) has gear ratios better suited for our purpose. 1st is not as low as the OEM Camaro box. However the aftermarket retro-fit units are not as easy to come by used. Last time I checked, the retro-fit unit was about $2800 new.
bill jacobson

I see, thanks for the information. I seem to recall mention of two overdrive gears, would that be correct?
Also, what sort of axle ratios did those cars run?

Jim
Jim Blackwood

I just measured my distance from the bellhousing rear face to the center of the shifter opening and got 21-1/2". From this it looks like the T56 is too long even without the adapter plate and would require moving the shifter hole back almost 4-1/2" after the 1.9" adapter plate is figured in. I certainly hope there is something closer.

Jim
Jim Blackwood

Jim, don't give up yet.

This page shows torque ratings & gear ratios:

http://www.5speedtransmissions.com/6_speed.html

This Chevy High Performance article mixes & matches Corvette & Viper parts to relocate the shifter:

http://www.chevyhiperformance.com/techarticles/148_0405_tough_t56_transmission/

I know of two companies that have a thinner adapter (plate), but they are not available separately.

The .80 5th gear with the .62 6th gear is the way to go. Who in the world needs a .50 overdrive besides Bonneville racers?

I talked to a ZR1 Corvette owner. He said the car is faster in 5th gear. Acceration drops way off when shifting to 6th (.50). He said 6th was strickly for gas mileage interstate criusing.

My '91 Camaro T5 has 2.95/1.94/1.34/1.00/.63 gears. There is too much of a drop in RPMs from 4th to 5th to suit me, but I need the .63 because of the stock rearend. The T56 with 2.97/2.07/1.43/1.00/.80/.62 would be a big improvement. I need to do more research to see if the .80 5th & .62 6th gears could be swapped into the F-Body T56 that has the 2.66/1.78/1.30/1.00/.74/.50 gearset. That would be ideal to go road racing!

Maybe we should see if Dan LaGrou will make an adapter plate for T5 to T56.

Also, you asked earlier about T5 torque ratings. The factory models varied from 240-330ft/lbs. I have seen them rated 500-650ft/lbs. with aftermarket gears.
Carl Floyd

Carl, from what I've just read, the overdrive gears can be swapped out, the question being what is available. Here's a page with several articles on the T56: http://www.chevyhiperformance.com/tech/engines_drivetrain/transmission/
One builder even makes additional optional OD gears as single sets but they require a different mainshaft, yoke and possibly driveshaft.

The later T56's had a 2.66 1st gear which would work very well with the stock MGB axle, being about midway between the 1st(3.10) and 2nd(1.89) on the close ratio T50 I was using. I used 2nd to start most of the time but 1st on steep hills and for playing. Those OD ratios might be a bit much, with the 3.90 axle gears that's a 1.95 overall. The .84 of the T50 resulted in a 3.27 final ratio and it definitely needed another gear. Just how much of a jump from there would be ideal is the question, whether around .73 or .62 but I doubt I'd want the .50, and since the stock gears are set up in pairs and are dependent on the countershaft gearing the choices are limited. But with those numbers we should be able to go back and pick the right ones if we can find the right information about what is available. One of those articles (or it may have been some other one from the search I ran) gave some pretty specific information on how the OD ratios worked, but by now I've gotten so much of it confused with T5 info that I'll have to go back and do it all over. Anyway the point is there seem to be aftermarket OD gears available, and hopefully there is at least one paired set that is a direct swap with decent ratios, maybe from a ford T56.

I'm having some trouble figuring out the exact shifter location as compared to the T50, and that adapter plate isn't as big a deal as they'd have you think. It's just a flat plate after all, and you can buy precision aluminum plate pretty cheap on ebay. The machining is pretty simple too, hardest part being getting everything centered properly. Haven't looked for prices yet on that Viper tailhousing but the one price I did see for a new one was around 3 bills which is more than I will pay for one.

You said Glen fit one in a late model by grinding the case, any idea how extensively or deeply he ground into it? Since mine is a '71 it has a little less room in the tunnel but my engine is further forward, offsetting that some. Anyway it sounds like it should be possible to bump it out some as needed.

OK, I'm not giving up on it. But money is tight right now so I'm not going to just run out and buy one either.

Jim
Jim Blackwood

http://www.ttcautomotive.com/English/products/T-56.asp

3 0r 4 listed with 2.66 1st and 0.79 & 0.63 OD. Must be a possibility.

Jim
Jim Blackwood

Yep.

TUET1694 is a Ford Cobra app., though.

This adapter plate is what we need for a GM conversion. D&D Performance (that other D&D) does NOT sell them separately from their kit.

http://www.chevyhiperformance.com/techarticles/148_0305_t56_six_speed_transmission/photo_05.html

McLeod may. I have a catalog on the way.
Carl Floyd

"You said Glen fit one in a late model by grinding the case, any idea how extensively or deeply he ground into it? "

He did a tech session on it at the 2000 Ohio Meet. I really didn't pay close attention because, at the time, I was thinking "Why would anyone want to put that huge, heavy thing in an MG?" I mean, overdrive is great, but who needs two overdrives?! :)

Anyway, all I remember is him talking about grinding the ribbing on the sides. I may have a photo somewhere.
Carl Floyd

Vic,

Did you receive my reply to your email?

Jim,

Can't wait for that McLeod catalog.

-----------------------

6) Q. I have an early Chevy and I want to install a T-56 transmission to it. Does McLeod make an adapter for this installation?


A. McLeod makes an adapter plate to mate a T-56 transmission to your stock bellhousing. McLeod also makes Modular Bellhousings for Chevy, Pontiac, Oldsmobile and Ford small and big block engines, to fit a variety of transmissions to these engines, including the T-56.


7) Q. I am thinking of buying a Tremec T-56 or TKO 500/600. Does McLeod make a shifter to fit these transmissions?


A. Yes. McLeod makes shifters for the T-56, TKO, and T-5 transmissions. McLeod makes these shifters with up to 2” offset right or left, and up to 4” offset front or rear.
Carl Floyd

McLeod T56 to GM bellhousing adapter plate:

http://static.summitracing.com/global/images/prod/large/mcl-8-207_w.jpg
Carl Floyd

Not much to that, looks to be maybe 5/8" thick. I think the more relevant question is how much room is needed. I talked to Glen over the weekend and what he told me was that not only did he grind the heck out of the case, really grinding down the reinforcing ribs, beat the heck out of the tunnel, enough to make the cowl vent unusable, but occasionally the transmission would still contact the body (once a year or so going over RR tracks he said) and the tranny and engine had to go in as an assembly.

I still like the idea of a 6 speed but that seems a bit much.

Jim
Jim Blackwood

Thanks, Jim.
Carl Floyd

OTOH, Vic said that he had the transmission up into position and felt that not much beating would be required. After another short talk with Glen, it turns out that this was a CB car, same as mine, and that he had the engine positioned rearward about an inch, I understood him to say, from the factory location. Mine is positioned forwards, and this might make a considerable difference in the amount of beating required to make it fit. I'm still waiting on Vic's reply as to whether he was putting it in as a unit, or presumably cut the rear plate. I very much doubt there's room to slip it over the plate and then slide it forwards to install.

Jim
Jim Blackwood

Interesting.

I was thinking today about asking you if you had asked Glen which tunnel was involved. My '79 would have way more room than a CB. ;)

Still need to work on shifter relocation & possible changes to 5th & 6th gear ratios.

McLeod catalog arrived today.
Carl Floyd

Maybe a little research to see if the OD gears out of the Ford box will work in the 2.66 GM box. I bet they will but that's probably another 2-3 bills.
Jim Blackwood

Check this out Carl. My car may just happen to be ideal for this swap. I did some checking and the rear face of my bell housing is maybe 1-1/2" back from the vertical face of the firewall above it, and there is about 4" of vertical clearance at that point. Looking at the adapter plate and assuming the diameter of the throwout sleeve flange to be about 4", the clearance needed above the T-50 case (going by the stock GM 4 speed bolt pattern) would be less than that, at that point. From there the transmission hump tapers downwards some but so does the transmission, so I think it is just possible that it might clear without any modifications. Crossmember fabrication should be easier too since the transmission won't extend as far rearward, and the shifter hole cover plate can be rotated 180* moving the shifter boot several inches to the rear which should accommodate the shifter location. If I need an intermediate location I can just make up a new plate. This swap is starting to look better and better.

Jim
Jim Blackwood

Here's the third installment of that HR article:
http://www.chevyhiperformance.com/tech/engines_drivetrain/transmission/0601ch_1968_chevy_camaro_transmission_install/

Jim
Jim Blackwood

Here's the hot ticket, for anyone with about 3 grand to spend on it. A bolt-in T56 that will fit, and if you ask nice they might even set it up with the gears you want. Should be just about ideal with the stock axle ratio.

http://store.summitracing.com/partdetail.asp?autofilter=1&part=MCL%2D8%2DT56%2DGM3&view=1&N=700+400374+0

The Richmond 6 speed, in about the same price range, has a single .075 overdrive 6th gear and 1st is down around 3:1 which would work well with the more popular axle ratios. But it has an external shifter and I don't know anything about how quiet it is. Then there's the Getrag which should be able to go anywhere a late model T56 will (I understand the only difference between that and the '93-'97 is in the pilot bushing needed, YMMV) and then there's the BMW unit which I still know nothing about.

Jim
Jim Blackwood

Carl, I need your help. (Actually anyone with a stock axle could do it.) I need to know what the engine rpm is at 75mph in 4th gear (1:1 direct drive) and the diameter of your tires, to get some sort of handle on whether or not that .5 OD ratio is even workable. Help please?

More info: The adapter plate for the T56 to early bellhousing is 3/4" thick. To make one, a suitable piece of Mic-6 precision ground cast aluminum plate on ebay should run about $50. The center hole can be cut with a holesaw, the throwout pilot bolted in place and the plate clamped and dial indicated to both the tranny and bellhousing and transfer punched for the bolt and dowel holes and drilled on a standard drillpress. The outline marked at the same time and a portable bandsaw used for cutout and angle grinder for finishing. Since I have some 1" Mic-6 on hand I'll probably use that.

According to one source the OD gears can be changed out. Another says they can't. Still looking into it.

Jim

Oh, and I'm going by the BMW shop tomorrow.
Jim Blackwood

Jim, here's a handy calculator to use for engine speed, axle ratio, tire size, or transmission ratios. All you need is to plug in the information you have in three of the four fields and it will give you a chart of the results. If you know your tire size and axle ratio, then you can plug in the T-56 ratios and see what the engine will be turning at any speed.
http://www.f-body.org/gears/
Bill Young

Jim,

I had my speedo pretty close, but when I went to the 215/55-14s it reads faster now. That calculator should do the trick.

I've thought about the .5 6th gear, but my little 215 doesn't pull very well at 2 grand & under cruising. Plus, my next engine will have a lumpier cam that will want to see more RPMs. With the stock rear, I'm pretty sure that the 2.66/1.78/1.30/1.00/.74/.62 would be my ideal setup.

It takes at least 4.10 to 4.33 gears & some torque to live with that much overdrive. Shorter tires would work, too. ;)

Yeah, for about $2500 or so, the Tremec T56 that is a direct replacement for the T5 in a Third Gen. Camaro would be the ticket.

I had another thought, fab an adapter plate to bolt a Ford T56 to a GM bellhousing. That would get you the 2.66/.62 gearset and possibly a more favorable shifter location. Make one for me while you're at it. :)
Carl Floyd

May want to save this info. Found it in Google's cache. Not found on the website any more.

Ford tranny dimensions:

http://72.14.209.104/search?q=cache:mHgtGclAj04J:www.fordmuscle.com/archives/2002/09/transmissions/index.shtml+ford+t56+dimensions&hl=en&gl=us&ct=clnk&cd=13&client=firefox-a

Also, Ford makes an aftermarket T56 to replace a Ford T5:

http://www.drivetrain.com/fordt56inst.html

That T56 shifter location is real close to my '91 Camaro T5.
Carl Floyd

If you can open an Excel spreadsheet, then here is a handy little tool for figuring out gear ratios, speed, rpm, etc:

http://www.britishv8.org/Articles/chart.xls
Dan Masters

Dan, the spreadsheet is great but it needs another gear.

I did several runs on Bill's calculator. While it is true that the .63 OD with 3.90 gears and 26" tires is about right with 72mph@2300rpm, my car has 24" tires bumping me up to about 2500rpm. Which is not bad considering that I'm running about 3400rpm at that speed now but it's not my target either. However, the .5 OD puts me down to 2000 at that speed, just a smidgen low. With 26" tires you'd be at about 1850.

The bad news is that so far I've not seen a Ford tranny with the 2.66 gearset and .63 OD (They all seem to have the 2.97 gearset) so there doesn't seem to be any advantage in going with a Ford unit other than the flat rear mount and maybe the shifter location. Input shaft might be a big issue for BOP/R use. The only three T56's I've found with those ratios (other than aftermarket) are the TUET1694, TUET1576 and 1386-000-021 which Jimi Guthrie says are Aston, etc. and only available through them, probably with unusable bellhousings and input shafts. I've lost the page with the tooth counts but IIRC the count on the input gearset was different, meaning a ford or GM input shaft would not interchange. That means the only way to get that package is with the RSG conversion ($$$) so far as I know right now. So if you go with the 2.97 gearset to get the rpm's up at cruise you'll be stuck with a first gear very close to what I have now (3.10) and with 26" tires it'll be usable, but you'll probably skip to 2nd as often as you use it. (a seat of the pants guestimate)

The BMW 6 speed is not an option with a 4.xx 1st gear and integral bellhousing. I have yet to look at the ZF 6 speed or the Getrag, though so I don't know if they are good options or not.

McLeod T56 from Summit: Carl, did you look at the photo of this thing? If a guy had $2700 to spend that is the case to have, but it would take about a 3.55 axle ratio to match the 2.66/3.90 setup in terms of a good ratio for 1st gear. Bearing in mind this is based on 24" tires. With that ratio, 65mph is at 2000 rpm, 75 is at 2300 and 150 is at about 4600. I think this setup works. With the 26" tires the numbers with the 3.90 axle are very close with 74mph@2300rpm. It looks to me as if this is the gearbox we are looking for and the spreads between the gears are much better, particularly between the overdrive gears, dropping 900 rpm on the first three shifts, 600 on the next and 700 on the last in the 2000-3000 range. That's a reasonable compromise considering you can reach upwards of 135 in 5th gear.

Jim
Jim Blackwood

If I had $2700, I would add another $1000 and buy Ted's front end! :)

Did you see this:

http://cgi.ebay.com/ebaymotors/T56-T-56-Cobra-6-speed-trans-Heavy-Duty-No-Core_W0QQitemZ330055175151QQihZ014QQcategoryZ33733QQrdZ1QQcmdZViewItem

Go to their website and check the rest of the pictures.
Carl Floyd

Good work Carl, that's one I had forgotten and the gear spreads are much, much better for a performance vehicle. In the 2000-3000rpm range we get 1000, 800, 700, 600, and 700. With my car 2500rpm is 74mph which is acceptable, 5500rpm is 162mph, and 126 in 5th so these gears are very good. For your car the figures would be 108.3% higher or 92.3% lower respectively, so again, you're at 2300 for 74mph and 176 at 5500. Incidentally, 20mph is at 2900 and 2700 respectively in 1st. So, what are the differences between the GM and Ford (specifically 2003 Cobra) input shafts? I expect the same plate will work for either transmission, and depending on the dimensions it may or may not be possible to get two of them out of the one 2'square piece of plate I have on hand. A custom pilot bushing is likely needed, clutch plate should not be a problem, but we need to know the difference in length.

Jim

Jim Blackwood

An FYI for yall on the t-56 pushed up the tunnel--It is tight. There's is near zero circ air space. And a good speedbump could be a disaster. If I did go and do the T-56, I'd cut out the stock tunnel, install it all with engine in final position, then refit the tunnel and use some Miata seats. Cheers Vic
vem myers

Here's Jimi Guthrie's comment about the Cobra transmission: "That transmission is number TUET1260 it comes with a 2.97 first, it is either a misprint or they have done something special inside"

I'd say we need more confirmation before going on down that road.

Jim
Jim Blackwood

Ooops, must be a misprint on the number. The Tremec chart link above does show that number to be a 2.97 1st gear.

Of the three numbers you listed above, 1386-000-021 does seem to be an Aston. According to the chart below, TUET1694, TUET1576 are for Cobras.

http://www.classicchevy5speed.com/files/Tremec%20Specs.pdf

http://members.shaw.ca/Nightshift/S-10/TKOInstallDimensions_116_116_116.pdf

Sure would be nice to find a chart with dimensions/applications for all the part numbers.

Carl Floyd

I don't doubt that this transmission exists, it is just a matter of identifying it accurately. Some sites show it as the 2003-4 Cobra, some as the Cobra-R, some as neither and some as both. The problem with that is you either have to inspect it in person, know the identifying characteristics, or spend big bucks on it to get a guarantee that it is what it says it is. But a trip to the Ford parts dept. should sort that out, I would think.

Jim
Jim Blackwood

http://www.hononwah.freeweb-hosting.com/home/home.htm

This is a project where the tunnel was removed and placed rearward 7.5" (and probably never finished for reasons we understand quite clearly). However, it does show the fitting of the T56 in the tunnel. The victim is a 1972 GT, and if the cutout at the top of the tunnel represents the location of the console legs, then we can get a pretty good idea of the fit. I'd have to say it does look promising.

Jim
Jim Blackwood

I have a T-56 from a '98 Firebird in my '73 BGT and it works awesome. I am running a chev 350 producing 400+ hp and 400+ ftlb. This particular model/year transmission is rated to handle 450+ hp and torque and does have the .5/1 final overdrive ratio. Yes it is a heavy brute and requires installation with the engine as a unit but even when I had the 4 cylinder I removed the engine/transmission as a unit to rebuild anyway. I did need to modify the transmission tunnel to the point where my heater is permanently in the defrost position but this is where I always used it anyway. The location of the engine/transmission buts the shifter 2" aft of the original location, again working fine for me as the seats are in the rearmost location. Overall weight of the car with this combination and heavier brakes, minilite splined wheels and upgraded rear axle is 3000 pounds with 16 imp gallon fuel plus my wife and myself, weight distribution 1495 front axle and 1505 rear axle. With the 355:1 rear axle ratio and 225-75R15 tires she runs 2000 rpm at 80 mph, 1500 rpm at 60 mph, giving me 35+ mpg highway and 0-60 times of 4 seconds. I actually have more of a space issue with the exhaust than I had with the engine/transmission package.

My business neighbour has a 77 B convertible with a cast iron head chev 350 and a t 56 plus his cousin has a Miata with a Fuel injected x camaro 350 and t-56. While the 6th gear may not be always needed, with the low end torque I've got, it really is a blast to drive, it's reliable and it wasn't that much of a problem to install.

Brian Yeates
Jim Blackwood

Odd glitch there, I sent Brian the link to this thread, but it was under my log-in. Therefore his post has my header. Strange, but true!

Jim
Jim Blackwood

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=300057289385&fromMakeTrack=true

T56 on ebay, 10 available, $1195. Has the right gears, or so it says.

Jim
Jim Blackwood

Plus $400 core charge. Still not a bad deal.

Wayne
Wayne Pearson

Brian, That sounds like a very successful conversion. How much work did you have to do to the transmission tunnel to make it work, and what sort of difficulties did you have with the installation of that engine/tranny combo? What do you consider the biggest challenges or drawbacks? (Can we assume the heater is gone?)

It sounds like those ratios are working out all right for you with that big engine. Might be an entirely different matter for Carl, though I for one don't believe his engine is as weak as he claims it is, and it could be too much gear for me as well. I don't know what the results would be of running a low vacuum or possibly even being into boost at cruise. Currently I can cruise at 12-14" vacuum, (about 17"@ 3400rpm in neutral, cold) but that much change in gearing is sure to make a difference. The question is how much. If I were to make the assumption that the Cobra transmission is right for Carl's car, that yours is right for your car, and that mine falls roughly in the middle of the two (does your transmission have the 2.66 1st gear?), then it could be that the .5 OD with the 3.90 gears would work for me, putting me at 73mph@ 2000rpm.

Wayne, yes I had overlooked the core charge which does drive the price up quite a bit. But still not bad for a rebuilt, dyno'd and guaranteed unit, so I figured I'd post it. I *have* heard of them selling for as little as $500 but of course that's just a rumor. Most junkyards will know quite well what it is and what it's worth, but bargains are out there, if you can find them.

Jim
Jim Blackwood

Jim

To fit the T-56, I did have to raise the top of the tunnel towards the front and this eliminated the heater as a heater but it is still fully functional as a defroster. Also had to widen the tunnel for the bellhousing, but more so on the right side than the left (driver) side of the car. When I was running it with an Edelbrock RPM Pro-Flo fuel injection, I was getting 16-17 " vaccuum at 1500 rpm on the highway so had no problems in that regard and lots of go even in the higher gears and lower rpm although for real get up and go I can drop two or three gears and put my foot into it. First gear really could be considered unneccesary but the two top overdrives make this package work well for me. Probably way too much transmission for a 215 or one of its variants though. There were many variations of this transmission made and used by a number of different manufacturers over the years. I'm not sure what my first gear ratio is, but it could be a real stump puller coupled with the 3.55 rear axle and the 24" diameter tires. when I first completed the car I was using the stock mg rear axle with 3.91 ratio and first really was useless, I only used it because it was there!! The transmission is heavy at 125 pounds dry. Installation required blocking the front tires on 8" cinder blocks then lifting the rear end as high as possible on a long-arm floor jack and dropping the engine/transmission in on an extreme angle then gradually lowering the bakc of the car, supporting the tailshaft of the transmission and raising it into position as the engine was simultaneously lowered into place. Bit of a juggling act when doing it alone but a great fit when done. Can send pix on request.

Brian
Brian Yeates

One of the secrets I learned from Jim Stuart is to create a removal slam panel, allowing for a more-or-less a straight-in/straight-out approach from engin installation/removal. Eliminates some of the need for of elevation to get the transmission tail into the compartment and over the frame member.

I left a couple of ~6" ears on either side of the inner fenders of the original slam panel...then shortened a new slam panel a little bit on both ends..it then bolts on to the ears of the old slam panel.
rick ingram

Jim,

You need to logout before sending those links.

"I for one don't believe his engine is as weak as he claims it is..."

Not the first time I've heard that. Try 160 HP dyno'd at the rear wheels. The Dragon is not a horsepower track. ;) I was just driving it really hard. I get smoked on straightaways.

At the first MG V8 meet (pre-V8 for me) on the drive out to Summit Point, one of the guys made me open the hood. He didn't believe that I was mostly keeping up with a stock 4 banger under the hood.

I still think that gearset would be perfect for my setup. Not keen on the shifter location, though, as I still have the stock console.
Carl Floyd

Carl, you are correct about the links. I had no idea it'd do that.
Anyway, I guess that explains the super sticky tires. 160 is plenty of power for the MGB (I ran quite awhile with less than that and was perfectly happy with it, even after having about 240) but I can also see where you'd want an edge of some sort.

Brian, thanks for the information. This tells me that with the amount of space I have between the engine and firewall I am very likely to not have to do anything at all to the tunnel. Just what I was hoping for. I would like to see your photos if it's not too much trouble to send them.

Jim
Jim Blackwood

I was wondering if some of the members with a spare transmission sitting around could take a measurement and give the results? I'd like to know the length from the mounting face where the transmission bolts to the bellhousing out to the far end of the clutch spline where the pilot bearing journal begins. I'd like to have this measurement for:

1) Older GM (Muncie, etc)
2) GM (LT1)
3) GM (LS1)
4) Ford (T56 or T5)
5) Viper (if anyone can get that) This is a long-shot choice but is here for completeness.

Since the input shaft length could limit our choices we need to know if it does. So anyone who can take a measurement would be helping out a lot.

To get a straight line measurement, try putting a square parallel with the shaft and using something with a 90* corner (sheet of paper works) to contact the end of the shaft spline. Thanks,

Jim
Jim Blackwood

I am following that debate that I found interesting. I searched for some other goods on e-bay and come across Honda 6 speed gearbox. I do not have any data, but looks pretty slim and similar to original B gearbox.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=220058338899&ssPageName=STRK:MEWA:IT&ih=012#ebayphotohosting

toni


Toyota Bellhousing.
http://www.dellowauto.com.au/main.html

I'm told (better check up on this) that the bolt pattern is the same on the 6 speed.
Peter

Dellow Automotive has some good info in their catalog. They do show the ratios in the Toyota gearboxes. 5th gear in the common ones is .85 or .86. I think that's fine if you have the 3.07 gears, but still results in too high an RPM at highway speeds. It's worth your while to read the catalog.

So, I say the Best 5 speed's for the Rover conversion are:
1. The Rover 5 speed (LT 77)- same complaint as the Toyota 5th ratio. I put this 1st only because it's Rover and is what was put into the original MGB V8's and early RV8's. Parts are expensive, have to pull the engine to get the tranny out. This is what I put in my conversion.
2. T5 - 20/20 hindsight says to me, my car wasn't originally a V8, so if I had researched this a little better, I would have gone this way. Found the one with the .6? 5th and been able to keep the original rear end. Parts are more available, don't have to worry about the oil pump in the transmission. It would probably shift as well or better than my LT77 (that's a guess).
3. Toyota - at first this sounds fine. But after reading the Dellow auto catalog, the ratios aren't what I would want. And for whatever reason, I have a problem sticking a Japanese part in my British car. (at least the T5 is USA and we are sortof like the Brits ;-) )

I looked on eBay for 6 speed transmissions. Specifically the S2000 ones. I drove a new S2000 and it had the most crisp, tightest, best patterned, best feeling manual transmission I have ever driven. (Never driven any other 6 speed). What suprised me is the availability and low price of it on eBay. I think it's 6th gear suffers the same problem as the Rover and Toyota. However, if someone offered an adapter for it to the Rover, I would be tempted to go to it (with the 3.07 gears). While I think my B would still outrun the S2000, I don't turn nearly the RPM as the Honda did. I was shifting the S2000 (brand new on test drive) at the redline of 8500. My wife was majorly panicked... it was fun to say the least. Anyone ever looked at this transmission?

By the way, the above are my opinions only. Keep it civil when you slam my choices and thoughts.

Anyone ever had their V8 or otherwise (or street driven B) to an honest 150MPH? I have been to about 125 in 5th with the 3.9 rear. Felt stable but a little twitchy.

Merry Christmas
Richard

Richard Morris

This site has the S2000 ratios on it.
http://www.hondanews.com/CatID2069?mid=2003100141147&mime=asc

Richard
Richard Morris

The thing I noticed about the Honda transmission is it's torque rating. At 162 ft/lbs it isn't going to be strong enough for any but the mildest BOP/Rover engines. Don't know about the Toyo.

Jim
Jim Blackwood

I've sent Ken a Holiday/Birthday card....and queried as to the status of his gearbox....I'll let you know what I discover...

Cheers!
rick ingram

What engine was used in the MG X power? It says an aluminum 4.6L V8 (2001) and gives these ratios for the t56 that was used with it:

Gearbox:Six speed manual Ratios:

1st
2.66:1

2nd
1.78:1

3rd
1.30:1

4th
1:00:1

5th
0.80:1

6th
0.63:1

If it was the Rover engine it'd be nice to know there was a pattern for it, and maybe it could even be reproduced.

Jim
Jim Blackwood

Anybody seen the Zeroshift mechanism? Looks good, can be retrofitted. Would be good if someone local could contact them about it. The ideal solution might be a t56 with rover bellhousing and zeroshift. Sounds expensive though.

Jim
Jim Blackwood

Hi Jim,

The Ford Mustang 4.6 DOHC Cobra motor was used in the MG X-Power SV & SV-R.

Cheers

Pete
Pete Mantell

Thanks Pete. I saw that after the fact, I was just wondering who else would know. Too bad though.

And on the Zeroshift modification, it would undoubtedly be necessary to replace every synchro and every gear engaged by a synchro to do the job so that's six gears and three sliders. At an average estimated cost of a couple bills apeace the cost to convert could easily run $1800, which means though Zeroshift might be able to supply them for $2500-$3000 as remanufactured replacements it'd certainly be at the high end. Out of curiosity I sent them an email. If they respond I will let you guys know.

Jim
Jim Blackwood

This thread was discussed between 09/11/2006 and 01/01/2007

MG MGB GT V8 Factory Originals Technical index

This thread is from the archives. Join the live MG MGB GT V8 Factory Originals Technical BBS now