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MG MGB GT V8 Factory Originals Technical - Rover V8 compression ratios

My son and I are doing some research for the next project, which needs to be more interesting than his PS2.

We are thinking of building an MGB with a twin turbo Rover V8. I know some Land Rovers used a 3.5 with 8.13 compression ratio. Starting with a low compression engine seems like a good idea. Does anyone know if the standard pistons in these will take 7 or 10 psi of boost. We intend to use charge coolers to keep the inlet temp down.

Also does anyone know if any vehicles used the 3.9, 4.2, 4.0 or 4.6 with a low compression ratio around the 8 level.

Does anyone have pictures of a twin turbo V8 in a B?

Thanks

David
David Witham

I think all the 3.5 Land Rovers had the 8.13 CR. Biggest problem you may have is room next to the manifolds for the turbo and then getting rid of all that heat. Janspeed did a V8 twin turbo conversion that looked like it could be made to fit. One was on E-bay last week but appears to be gone now :(

Good luck
Stuart Robson

You could use the later composite headgaskets which are thicker than the original tin ones and also seal a lot better.
You could also fit the older style heads to the later engines which would have the same effect.

Go for it.

Mark
Mark

Here ya go:

http://v8scimitar.co.uk/technical/rover_v8_engine_numbers.htm

Will the stock cast pistons stand 10 pounds of boost? I don't know. You might ask the nitrous oxide boys what pistons they use.
Carl Floyd

Carl,

Those engine codes are very good, thanks.

I can from them that there were LC versions of the larger size engines. Were the larger engines only used in Range Rover and Discovery? I expect with those models most or all of the UK sold vehicles will have been HC.

Stuart,

I expect the manifolds will have to come up and forwards to the turbine and the out through the inner wing further forwards than an RV8 hole.

David
David Witham

You need Jim Blackwoods advice (I am sure he will pop up) but you might find a normally aspirated transplant more successful - have a look at: http://www.espritv8.net/id34.htm or Progress engineering near Maidstone - they used to supercharge 4.6s for armoured Range Rovers.

Heat is a problem and so is a lot of power - the MGB needs mods gslore to handle 300+ BHP sensitively.

FWIW

Roger
RMW

I am willing to bet that the actual compression is less than advertise.
The only way to know what you have got, is to measure the actual compression of the engine.
Guess work can cause problems specially with boost exceeding 7 lb
Bill Guzman

This thread was discussed between 01/03/2005 and 02/03/2005

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