Hi Guys

Hope this isnt 2 silly and idea but I have a completely bare golF GTI in my back yard and fancied dropping a bike engine ( or 2) into it.

VW / Audi engine transplants have been done 2 death and the latest vw engines come with nightmare like wiring and ECU / Clock / Key chip combinations ( have just put a 2000 bora V5 into a Mk2 ).

I thought a bike engine would be different. Would 1 engine be enough to handle the weight of a mk2 golf or would I need 2 engines side by side.

I have plenty of spare subframes gearboxes and diffs etc lying about so I wont be short of bits - except for the odd bike engine or 2.

So comments please

In my humble opinion, even if you build a really light VW, you'll probably be looking at around 800kg, one bike engine would surely not be enough. The strain on the gearbox, etc would be massive.

Bear in mind, whilst BHP output is amazing, sadly Torque isn't quite as much.

I think you'll have to go the two engined route personally...

...but don't believe me, I may be talking crap!!!

Nah you're absolutely right Raj, it will still be way too heavy for a single BEC install.

How do you plan on doing this, front wheel drive or rear wheel drive? The problem is, if you can actually get two engines in there and drive the rear wheels presumably, you've still got to work out how the transmission is going to work. I doubt you'll find chain drive strong enough with that amount of weight, and the Z Cars transfer boxes don't exactly have the highest reliability record even in a lightweight kit car.
I admire the thinking, but if you want my honest opinion, I'd steer well clear and get a light weight car to do a bike engine'd conversion on instead.

Chris

Best thing to do is ditch the Golf - or use it to grow plants on etc!!

Definately consider a Locost - Much more fun, better handling, better performance and the satisfaction that you built this beauuuutyyy.

Its up to you ...

Thanx 4 the replies.

I Really fancied something different in the golf so if 1 engine is not enough how about 2 1 driving the front wheels and one driving the rear with chain driven diffs.

Just got two have 250-300 bhp and 12k rpm in the golf - stripped out racer style!!!

Thats a possible way to do it, but it will handle like a total pig. Z-Cars have built a twin engine'd Tiger kit car with that configuration, one engine driving the back, one driving the front, and it took £10k's worth of engine management systems to syncronise the power enough to allow it to go round corners with any kind of conviction. To be truthful, I really don't see any kind of bike powered Golf being that feasible due to the weight, with two big bike engines in there weighing around 85kgs each (ZX12 or 'busa), it's gonna be getting close to 900-1000kgs again, but if you still want to give it a go, ZCars are probably the best people to talk to
http://www.zcars.org.uk/
tho it looks like the site is down at the moment

Chris

Theres plenty of twin bike engined cars competing in autograss events, so get down to your local autograss club quick before the racing season ends. Both engines are put in the back, linked (I think) mechanically by the final drive to keep them running in sync. You should be able to get more info on this on the national autograss forum, at www.yorkshiredales.uk.net/

Yup you can do it that way and drive the rears only, a lot simpler and will give better handling, a lot better than the 4wd option, just need to find the right diff and drive train etc.
Sorry, not trying to be a stick in the mud here, but I've still got a feeling that the weight is going to be a big factor, unless maybe you properly strip the Golf, lighten the shell extensively, junk the dash, junk all the suspension and fabricate lightweight wishbones etc, junk the glass, lighten the doors/boot/bonnet etc and make it a hell of a lot lighter, and even then I can't see the car weighing under around 800kgs with two suitable bike engines in there, as I don't see a stipped out golf weighing only 600kgs without engine(s). It might not be that bad at that weight I suppose, just don't expect the same performance a BEC powered kit car produces, and expect LOTS of complications and cost!

cheers
Chris

[Edited on 23/10/02 by ChrisGamlin]

I agree with Chris that the weight of the car would be rather excessive, the autograss cars I've all seen are stripped to the bare minimum they can get away with, so they have no floor behind the drivers seat, very little in the way of inner wings ( a front spaceframe is generally used to mount a custom made double wishbone suspension) and most of the panels,whilst still being metal, are skinned. A road car would also need windows, lights and other gubbins, which would all add further to the weight. However, a VR6 engine would go nicely in the back of a golf...

Hi Guys

I realise that a lot of the current BEC's are stripped out and lightweight but surely two bike engine produce a 50% more torque and 200% more power than a standard 8v golf GTI engine. Surely some sort of twin engine arrangment has to be the way to go.

I hadnt thought about twin engine rear drive. That appeals. Iknow that twin engine 1 up front and 1 rear can work as as Ian Birch from dubsport has been doing it for ages ( twin vr6 turbo mk3 each engine has 350bhp and no complicated electronics to balance split ).

Any comments on how to arrange the engines two drive a prop to rear axle or two driving straight onto some sort of rear diff ???

Your comments please

Remember quoted figures for peak torque and bhp don't necesaarily give a true picuture of the engines performance. Bike engines are high reving engines, they give there performance figures very high up the rev range. Car engines are designed to give a good spread of torque throughout the rev range. Its best to look at a dyno printout and see what performance the engines give at lower revs.

The twin bike engine installations I've seen in which the engines are mounted behind the driver all feature chain drive. Theres a twin bike engine installation in a single seat hill-climb car in this months Racetech magazine which is worth looking at.

There are other things to consider such as will the clutches stand up to it etc? Probably the best thing to do is have a long chat with Chris at Z Cars and see if he thinks it will be feasible, as he's the undoubted expert in the field of twin bike engined cars.

Chris