MG Sports Cars

Hi all, I'm new to this forum so apologies if I'm asking all the wrong questions.

Currently I have a 1980 Triumph Spitfire with all the bits and bobs such as fast road cam, balanced internals, stage 3 cylinder head, stainless exaust, etc… But I'm looking to go for something with a bit more power and a lot more torque.

I was interested in the factory MGB GT V8 which used the 3.5 Rover engine and was looking to do something like that, basing it on an MGB, as it would be nice to keep the Triumph as a modified 4 cylinder.

Having looked around there are a great number of (relatively) sound MGB GTs available from around £350. I decided that a GT like this would be ideal, partially after seeing the Sebring style arches on some modified cars. The other advantage of the GT is obvious if you live in England, as it rains most of the time.

As far as the engine is concerned I looked at the Rover 3.5 which in standard compression tune (9.35:1?), I'm told, puts out around 156 horsepower. Such engines can be had for as little as £300, throw in an LT77 gearbox from an SD1 and your sorted, people have said.

However others have told me that the older engines are prone to giving up due to the all alloy construction, even if they have been built well.

So I looked at other options and came across a company called Real Steel, who sell American V8s (in need of rebuild) for reasonable prices. Some of the more affordable options include the Ford 302 and Chevrolet 305 and 350. I know very little about these engines, but apparently a mildly tuned 350 will make a reliable 250 horsepower.

From what Iv'e read the 3.5 Rover will realistically struggle to make much more than 225 horsepower, and that will not be as reliable?

I have deliberately stayed away from modern EFI engines due to the electrical complications, and also the idea of a V8 in a relatively light car is appealing.

Obviously I know there is a fairly substantial weight penalty with the American engines, due to the cast iron construction, but this car will really be a car for straights, rather than corners.

So, what are your thoughts, with engine, gearbox and rear axle choices with these options?

Also what are the tuning options with regard to Chevrolet or Ford?

Thanks for taking the time to read this, Will

Will,
Of the engine you mentioned the Ford 302 is best supported. Pete Mantell has a kit to install it in a B.
Others with more knowledge of htis will surely join in soon.

Steve

Steve,

Thank you for your reply, do you know what can realistically be attained in terms of horsepower on the Ford 302?

I searched for the Pete Mantell kit and read some articles about 302 MGBs written by him but could not find a link for the kit.

Do you know if it is possible to use a manuel gearbox, or is an automatic a considerably cheaper and more common option?

Will, I took it from your post that you are in England. I don't know about the availability of either Ford or Chevrolet V8s there or the matching 5 speed manual transmissions (T5s) Certainly the most powerful option and easiest to install would be the Ford 302 based engine. You're far more likely to have access to the Rover V8 though with the 5 speed trans from a SD1. Not as strong as the WC T5 but far more common in GB. I suggest you take a good look at David Tetlow's MGB roadster [www.britishv8.org] which is a car built in GB and is both a great running as well as a great handling car. You can have both. Remember the Rover V8 is basically the same engine as the old 3.5 in the SD1 but now tips in at 5 liters in the TVRs and at 4.6 in a lot of Range Rovers, so you can get a lot more than 225 hp from one with ease.



Edited 1 time(s). Last edit at 06/24/2010 03:32PM by Bill Young.

A Ford 302 with aluminum heads will easly give 340 to 350 HP (at the flywheel) and still retain a smooth idle. With the factory iron heads, power will be about 100 hp less (approximately).

A lot of people on your side of the pond use modern engines in other cars. They remove the efi and go with carburetors and use a megajolt so they dont need to have a distributor. Look into that, may give you a few more options.

400 streetable hp should be fairly easy.

[www.carcraft.com]

[www.carcraft.com]

Jim



Edited 1 time(s). Last edit at 06/29/2010 10:52AM by Jim Stabe.

Will,

Bit of basic advice from the UK. The 1975 and later MGB's had the engine bay with mods to accept the Rover V8 and because of potential enforcement of legislation regarding the number of changed components a vehicle can have, may require SVA evaluation and testing, I think it would be wise to stay with a Rover V8 which of course was fitted to the factory MGBGTV8.

In the Uk the resale value of a Rover engined car is currently quite good but with a Ford 302 fitted you might struggle to sell it at some time in the future, If I was in the US I would have been tempted to fit the 302 though.

3.9 Rover V8 engines are readily available either as complete units with EFI or convert to an Edlbrock 500 carb and Performer manifold.

Budget £800-£1000 for the basic rebuild includingall bearings, cam lifters and timing gear ARP mains stud kit+ any upgrades.

You will also need to consider a rear axle rebuild with the V8 3.07/1 ratio otherwise the car will be seriously undergeared.approx £800, it does start to add up I'm afraid

A 3.9 with road heads and cam will easily produce 230 BHP and in a car weighing around 2200 lb. will provide more than adequate performance and good drivability provided that suitable upgrades are done to the suspension and the brakes.

Conversion parts are also readily available and I would recommend Dave Vale at V8 Conversions in Farnborough Kent 01689 858716

I also use Real Steel for engine parts and also Paul at V8 Tuner is a good source at good prices.

You can fit the LT77 box which requires a small mod to the roof of the gearbox tunnel and a new propshaft, 75/76 cars require the rad support brackets changing to mount the rad in the forward position of the 77-80 cars and thats all the structural mods required, the earlier cars require a lot of mods to the engine bay and the steering to clear the V8 engine.

I'll stop there before i try to re-write the book, there is good information available of how to convert your MGB to V8 power and I can e-mail you a copy if you let me have you e-mail address, whereabouts in the UK are you?

Kevin.




Edited 1 time(s). Last edit at 07/01/2010 06:24AM by castlesid.