Thinking of building a MGB GT V8 turbo.

[TomReade93]

Im thinking of Building a MGB GT Sebring style with a Rover 3.9L EFI V8 with single or Twin Turbo.
Ive seen someone start this before on retrorides forum and it looked amazing.

heard afew different problems with fitting a rover 3.9
would Sump foul on the stock front swaybar?
Will the rear axle take the power?
are there any problems with having to have a IVA or not? (Been through this before for a Defender 100" and don't want to go through it again!)
Is it easier to run a 3.5L Rover V8 with twin SU carbs instead of the EFI?

Previous car work is Building a Defender 100" and restoring a Frogeye Sprite.

Any help would be great Thanks

[v8250]

TomReade93 said:

Im thinking of Building a MGB GT Sebring style with a Rover 3.9L EFI V8 with single or Twin Turbo. Ive seen someone start this before on retrorides forum and it looked amazing.

heard afew different problems with fitting a rover 3.9
would Sump foul on the stock front swaybar?
Will the rear axle take the power?
are there any problems with having to have a IVA or not? (Been through this before for a Defender 100" and don't want to go through it again!)
Is it easier to run a 3.5L Rover V8 with twin SU carbs instead of the EFI?
Any help would be great Thanks

Tom, that's an interesting project. Yes, why not build a turbo charged V8 MGB...it'll go like a dingbat and with the right BOV + exhaust will sound crazily great. To answer your Q?'s

1. there are few problems fitting any of the Rover based V8 engines - just be sure to but a post 1976 car and the engine will drop straight in.

2. the sump fits fine - more importantly you will need to uprate the anti-roll bar depending what you'll be using the car for...and every suspension component with a system not designed in 1958/1959.

3. diff'...not a hope in hell's chance[!!] you will need to think very carefully about your peak engine output and then make sure the complete driveline is over-spec'd to handle the power. Here, we're talking BHP and Torque.

4. IVA/SVA is best left to a private discussion...one needs to be careful to ensure any changes to a vehicle comply with DVLA/SVA regulations.

5. if turbo charging you'll need an EFi engine including all the wiring loom, ECU [this will need to be remapped] and injectors [these may need to be uprated from the standard Bosch Green]

More importantly, where and how are you going to install the turbos. Logically you'll take the manifolds out through the inner wings...but trust me, there's no room for a turbo unless you cut out most of the inner wings which in turn will need significant bracing. Turbo-wise it would make sense to go with one that's readily available like those from Hitachi/Fuji Heavy Industries as used by Subaru i.e. the TD04. They're compact, very efficient, cheap and can be bought anywhere. Though, you'll need to think carefully the up/down pipe layout...again there's little room between the V8 inlet manifold and the bonnet.

Also, if it's major on/off power you're looking for why not simply buy a bomb-proof rebuilt engine and add a nitrous kit. Much easier to complete and this has been done many times. May I suggest you have a chat with the guys on the V8Forum.co.uk. There's a lot of knowledge over there.

Either way good luck...we look forward to seeing the project.

[NBTBRV8]

Engine bay space and heat will be a major issue for you, there is barely enough room in there for naturally aspirated extractors let along turbos. Plus you'd have to think about an intercooler too.

Why not a 4 cylinder with a cross flow head and supercharger?

[v8250]

NBTBRV8 said:

Engine bay space and heat will be a major issue for you, there is barely enough room in there for naturally aspirated extractors let along turbos. Plus you'd have to think about an intercooler too.
Why not a 4 cylinder with a cross flow head and supercharger?

The intercooler can sit directly below a raised bonnet air intake positioned reward of the plenum. This would have two advantages, 1. it's a high pressure area :. very effective cooling and 2. one would naturally remove the heater box...things would be so hot in the bulkhead area I doubt a heater would be needed.

Having driven an 1800 with supercharger I was left disappointed and wanting. Performance was mediocre and against cost was very poor. Only interesting bit was the noise the supercharger made...as with most s/c's they sound great when on song.

If the OP's wanting quick dash for the cash as a V8 project I'd stay clear of turbo charging and go the Nitro route...or, why not an out of crate 400bhp Chevy unit brought straight from the States? They're exceptionally good value for money...£4-5k would provide a serious engine with all ancillaries...fully balanced and ready to go...and they're almost unbreakable.

[Church of Noise]

Interesting idea!

Maybe supercharging would be easier, as you could put the SC in the V, instead of having to find a spot for the turbo(s) - which seems horribly complicated.
Still, I don't think you could do either without it being externally visible, but maybe that's not an issue for you.

Fwiw, I have both a crossflow 4-cylinder car and factory GT V8 that might receive some more or less reversible power upgrades. Has a crossflow engine been turbo- or supercharged before? °evil thoughts°

Edited by Church of Noise on Thursday 14th August 11:59

[ftypical]

I once looked at building a V8 B GT from scratch. Complex enough without the turbos.

Why not just go for one of the larger capacity/more highly tuned derivatives? It won't weigh much anyway.

Or, you could follow the example of the hero who dropped a Jag V12 in one. From memory he had to reinforce the body shell, before starting on multi-link rear ends in order to cope with the torque...

[v8250]

ftypical said:

I once looked at building a V8 B GT from scratch. Complex enough without the turbos.

Why not just go for one of the larger capacity/more highly tuned derivatives? It won't weigh much anyway.

Or, you could follow the example of the hero who dropped a Jag V12 in one. From memory he had to reinforce the body shell, before starting on multi-link rear ends in order to cope with the torque...

Slight thread resurrection here.

ftypical, MGB V8 Turbos are not too difficult to do...though adding a nitro' squirter system will be just as much fun and much less work.

OP, have you started this project yet? It would be great to see how you're progressing...

[v8bloke]

MGB Diff is very strong indeed. Quaife LSD 3.07:1. I started with 250bhp then gradually increased the power with various upgrades over the last 14 years No problem at all with 368bhp. Now I have upgraded again with TA heads and new 5.0L and expecting over 400 bhp. The diff is strong the halfshafts are the thing to watch.
A Turbo MGB Gt would be epic. Go For it.
Mark

Edited by v8bloke on Monday 19th January 20:18