MGB conversion engine position query

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baggers
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MGB conversion engine position query

Post by baggers »

Firstly, hello to everyone, I've just come on board.

I am currently planning a 72 B GT conversion and have been doing a lot of reading on the subject, many helpful gems on here.

However, one question that is fundamentally bothering me: how should I determine engine (I have a 3.5 RV8 with a hotwire FI system on it) and gearbox (planning to use an LT77 or R380) position exactly? Depending upon how much I cut away for head clearance on on the bulkhead and in the gearbox tunnel I can push the engine back a variable amount, but this would mean having to move the engine mounts on the chassis rails.

Should I basline all positioning from the chassis rail mounts and work back from there, making space as necessary?

Any notes on best practise appreciated! Will get some pics uploaded soon.

Cheers.



kiwicar
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Post by kiwicar »

I am not able to comment specifically on the MGB but some general comments on engine position.
If the car is for mostly for general road driving and needs to give maximum comfort to the driver and passenger then the engine wants to be as far forward as practical, the front cross member will probably dictate this, with the position of the gear leaver also being significant.
forward position will reduce cabin temperature, simplify exhaust routing and will simplify fitting everything in and give you room to maintain it.
If it is for performance/ track use then you want it as far back as you can, this will bring all the mass as close in as possable making turn in quicker, ballancing the car giving the tyres and suspension an easier life.
Sorry no simple answer but others will come on and give you measurments.
Mike
poppet valves rule!

chodjinn
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Post by chodjinn »

You have to be careful with the front end of the engine catching the steering rack - there is literally only millimetres of space on mine, and similarly I only have a few mm of space between the heads and modified bulkhead. You can't use the original B series engine mounts either and new ones will rewuire welding to the chassis. I've got a brand new set of engine to chassis mounts here if you need them.

Dont forget that the gearbox tunnel will require extending vertically infront of the gear lever to accomodate the 'box, by a couple of inches. And depending on what exhaust system you use, the front inner wings might need chopping about a bit.

baggers
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Post by baggers »

Thanks for the input, sounds like the best place to start is ensuring that I clear the rack and start working back from there.

chodjinn
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Post by chodjinn »

well let me know if you want photos, as my 'B is up on axel stands at the mo with the entire front of the engine bay removed so it's relatively easy to see everything and take piccies 8-)

baggers
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Post by baggers »

I picked up a v8 conversion book by Williams at the weekend, has made this crystal clear. No need for any photos, but thanks anyway.

JC.
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Post by JC. »

I deliberately use post '76 cars as base from which to do a v8 conversion as there are no body mods to do.
Image -JC.

v8mgbgt
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I would start with a Rubber bumper body or a heritage shell

Post by v8mgbgt »

I did a chrome bumper conversion and it was a lot of work compared to the rubber bumper engine bay which is already modified.

I believe heritage do a chrome bumper shell with V8 modified engine bay.

Have a nice mod for removeable slam panel to make it easier to get the engine in and out. Will add it to my site sooon as I get a chance.

http://www.mgbv8.co.uk/

3xpendable
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Post by 3xpendable »

Thanks for that, interesting site. Take a look at the progress of mine here in the 'Your Garage Scene' forum.
1971 MGB GT (V8 project)

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