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MG MGB GT V8 Factory Originals Technical - V8 information

Hi.
I'm new to MGs and would appreciate some advice.
I have a UK spec 77B that I would love to convert to a 3.5 rover v8. I've had a quick read of Roger Parker's site and I'm more confused than ever.
Apparently this model (its got a body number of 426xxx) will accept the 3.5 engine as a bolt in conversion.
Question is: What parts and other work is required to convert, assuming I use either a t5/rover or most probably a 5spd toyota gearbox? Besides the inner guards for the rv8 style exhaust, does anything else on the body have to be 'cut'? Will the steering have to be modified?
Is there a simple list of parts I can access via any website?
Thanks so much,
Matthew.
Matthew

Matthew,

there is also a book 'How To Give Your MGB V8 Power' available. All your questions will be answered there in detail and solutions shown on pictures too. You should have it read before starting your conversion!

For a quick overview you should go here:
http://www.mgcars.org/v8conv./v8convs.html

cheers

Ralph
Ralph

It should be almost a 'drop-in', compared to earlier body shells, as the 77 and later models used the panels, mounts and other components from the V8 even though the V8 had ceased by that time. You don't even have to cut the inner wings if you use the pre-RV8 tubular manifolds.
Paul Hunt

You won't need to alter the steering. You will need a better radiator and you might have to do some mods in the transmission tunnel, depending on which gearbox you use. The gearbox cross member will need to be altered to support the new gearbox.

As the Rover V8 is not a revvy engine, you will almost certainly want a higher rear axle ratio - 3.07 is the best and was fitted to factory V8s, but these are hard to find. You can get new 3.07 crown wheel and pinion sets, but fitting them to your axle needs a little engineering to be done. Your speedo and rev counter will need altering.

The V8 engine itself doesn't go straight in as you have to alter the oil pump which wants to occupy the same space as the steering rack, and move the oil filter to a remote position. You may also have to get a different water pump, and will have to reposition the alternator. Fuelling the engine gives lots of choices. You can use the factory SUs on a replica of the factory manifold, or lots of folk use the Weber/Edelbrock 4-barrel carb with a low rider air cleaner. Fuel injection is also possible, but needs more work to get it under a standard bonnet lid.

As Ralph says, you really do need to buy a copy of Roger Williams' book "How to give your MGB V8 power". It goes through the whole process. The picture is of the first edition. I think he is on version 3 now.


Mike Howlett

Matthew asked: "Is there a simple list of parts I can access via any website?"

No. One of the very coolest things about MGB V8 conversions is the sheer variety of parts and designs used. Almost every conversion is unique!

If you really want a list of parts to use as a starting point, the smart thing to do is to go the the "British V8" website, where over 200 conversions have been featured in "How It Was Done" articles. (That website has about 5000 big, color photos of converted MGB's!)

You can look through the articles and select a car you particularly like, and then use its "HIWD" article as a shopping list. On the other hand, you can surf the site to take a survey of what people are doing. The same website has a huge, searchable archive of informative articles and an active message board.

Here's the link: http://www.britishv8.org

Curtis

Mathew, welcome to the fold.You don't say where in Oz you live but you should check with your local motor registry first.You're almost certainly required to submit a certified/approved engineers report to register the car. I would suggest you find an engineer first before you start any work. Your local registry will supply a list of engineers for this purpose. IMHO, the Toyota gearbox is the best option in OZ. Barrie E
Barrie Egerton

Thanks all for your help.
I havent yet started any work, so good advice from everyone.
I'm located down in Hobart Tasmania and have already had a 'chat' with Service Tasmania (Govt) and contacted an engineer. The engineer seems to think it wont be a problem as long as I upgrade the brakes and involve/advise him of what I plan to do prior to any work.
Matthew

Matthew,

Here's a website for you to study. http://www.aluminumv8.com/
D&D is one of the major US suppliers of Rover V8 conversion parts in the US.

Strange that we have lots of those Celica transmissions in the US, but no kits to convert them for V8s or 1800s, or anything. Is this an opportunity for some ambitious supplier?

Cheers,
Allen
Allen Bachelder

Hello Matthew,
Cheapest option is a manual Leyland P76
Next a manual Rover, a P5 or P6.
Or a manual Rover.
The above are the cheapest, but aren't the best, or easiest.
Engines- the 3.5's tend to developed cracking around the crank bolts. They can work loose over time and the crank moves. If you find a good one, use studs, or cheaper, stud locker on the bolts. The 3.9, 4.0,4.6 rover, or range rover engines had their block reinforced, and are a much better engine.
EFI- this is easier and cheaper to adapt to MGB's than it is to set up carbies that will fit under the bonnet. We can give you all the details.
You need to get the remote oil pump base
i.e. http://mgv8.homestead.com/v8con.html
The bottom pulley and alternator bracket, plus other bits, can be got off old Rover's much more cheaply

Gear box, in Australia we are very lucky to have Dellow automotive. He makes all sorts of bell housings to fit Toyota supra (or Celica) gear boxes. These boxes are small, light and very strong. They fit into the MGB transmission tunnel with room to spare. Other gear boxes, like the manual rover for example, need you to do a little cutting and welding.
You can buy one of Dellows refurbished gear boxes for around $700 to $800. I've got a W58 supra box. This has the 0.78 fifth gear and is a little stronger and lighter than the Celica. Look on his site and you will see that there are a variety of options.
http://www.dellowauto.com.au/
scroll down to rover or Leyland P76.
You need the longest gear stick position for MGB's, the 21".
You need a one inch clutch slave to go with the MGB master. Don't get Dellows 3/4 inch Toyota clutch slave cylinder, too small. He used to offer a 1". actually a 1 and 1/16th, (off an early Holden, I believe) slave set ups. Ask for those. If he no longer supplies these then you can use a one inch rover or range rover one (that fits the MGB hose).
You'll need to either find a manual rover flywheel (rare) or get about half an inch machined off the face of a Range rover flywheel.
The later (yours) MGB's had the same radiator core as the MGB GT V8. With the RV8, through the guards style extractors this should suffice. I got a very nice shiny alloy custom one from race Radiators in Dandenong Victoria. They make lots for MGB V8's so you can just ring and ask for one. About $600.
Do get "through the guards, RV8 extractors". They solve the overheating problems for good. The wheel wells are a low pressure zone and with the RV8 style all the hot air is sucked out of the engine compartment. Plus your starter motor becomes much more reliable. The best exhaust extractors for MGB’s are made in Adelaide. AAAutomtive. Adrian Ackhurst. They are a true triY extractor, unlike RV8 ones, which although much better than "block huggers" aren’t anything like as good a Adrian’s. I wish I'd got them.
http://www.britishv8.org/MG/AdrianAkhurst.htm
he's got brakes too!
These are from a Volvo if you wanted to adapt a set your self. Use Peugeot 505 turbo disk with redrilled holes.
MG workshops in Melbourne used to do a full kit, hoses and all, which I have and am happy with.
Peter

Should add,
The engine compartment is fully set up for the V8 engine. The only thing you have to do is cut holes for the extractors, which is easy.
After you get the engine in and going, you WILL want bigger tyres and wheels. 15 by 6's superlites (minilite replicas) with 195 by 60 high speed tyres will fit under the standard guards.
You should also fit antitramp bars, which are easy enough to make, but easier to buy. The MGB springs can't really handle the torque without the anti tramps. I drove around without them for about three years and just can't believe how much better the car is with them. Gets the power onto the road.
Peter

Mathew
Go see David Short 320 Elizabeth St. North Hobart. He'll set you on the right course. Tell him Willy said to come and see him.
Willy
WillyRevit

" The engineer seems to think it wont be a problem as long as I upgrade the brakes ..."

That doesn't give me much confidence in your engineer.
Carl Floyd

Carl
Tasmania is a small island off the bottom of Aust.
There have been several V8 conversions done here and the Transport dept. here know exactly what to look for to make sure of the quality of the conversion. As there are no body modifications needed for this conversion an engineers input is not required. BUT Mathew will have his car inspected a few times during the conversion by the Transport dept. engineer to ensure his workmanship is of approved quality, I have dealt with them several times and the only way to go is top quality work and keep them informed of everything during the job.
Basicly it is a dead simple conversion and the Transport guys know that. Cheers Willy
William Revit

I run bone stock MGB brakes. Even with sticky tires, I can still lock 'em up. I have run my V8 conversion for 5+ years with track days & autocrosses sprinkled in, plus two very hot runs on hte Tail of the Dragon. My stock brakes have never let me down.

They should not require that the brakes be upgraded.
Carl Floyd

Carl
I fully agree a well sorted set of std. B brakes with good linings/pads is all that is needed and works well for the average road/club car.
When Mathew applies for his modification he will have to have a set of brake specs from a car equal or better than what he is building. In the case of a v8 MGB the factory MGBV8 specs are all he will need. Therefore std MGB brakes with modern pads will be all that is required.
On conversions I buit my first V8B in 1976 and have built a few since then. I don't think B brakes are up to the job for competition work. I have used ventilated discs on all 4 wheels for club racing and still cooked em up' hardly anyone here uses std brakes for comp. work as the local circuit would have to be the hardest on brakes in Aust. without doubt. It has three very high speed braking areas evenly spaced so the brakes don't really get a chance to cool out The guys on std. brakes really struggle. Willy
WilliamRevit

I'd agree about the brakes as well, After all the car gets lighter, not heavier. However the engineers like to be able to compare to an existing car. The MG GT V8 had the thicker disks (not ventilated) and the RV8 had ventilated disks.
Matt should be able to get away with standard brakes in good nick, however the engineer will almost certainly require an additional test, which costs money.
Peter.

The factory V8 also had slightly bigger pads, but I understand they will fit 4-cylinder calipers so can't be that much bigger. You should be able to lock the fronts (but not the backs) with steadily increasing pressure (i.e. not banging them on which will lock them easier) and if you can't there is something wrong. It's different tyres that have the greatest effect on retardation, and many people seem to opt for changes that result in lower pedal pressures, without realising that this results in less retardation from the rear (as both front and rear work at the same pressure), and hence less retardation overall.
Paul Hunt

This thread was discussed between 30/08/2008 and 07/09/2008

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