Hi Guys,
Having ummed and arred about what engine to use, I've deciced to sell on the 2.9 V6 heavy weight I had lined up and go with a Bike engine
I'm still at the very start of my second locost build so just gathering ideas and components. Having experience of a rather awsome Busa powered Dax I recall the gear shift/drive train being very positive and snatchy especially on the down change, I have wondered if it would make sense to smooth things a little by fitting a Cush drive (as on a few single cylinder bike sprocket carriers) between box output and rear diff???

A few other questions are:

Are there any chassis mods required to the book chassis to accommadate a bike lump?

What is the preffered diff to use?

What is the best prop to for a BEC??

And last but not least, what 0-60 is possible with a superlight BEC with 140-150bhp


Sorry for so many Questions!

Regards

Paul

You can get a prop made with a TRT (Torque resilliant Tube) built into it, which is in essence two tubes one inside each other bonded together with rubber, a bit like a metalastic bush. One tube makes up the engine end of the prop, the other tube makes up the diff end.

Are there any chassis mods required to the book chassis to accommadate a bike lump?
Nope not really, you'll need to make up an engine cradle of some desicription rather than use the X Flow engine mount points but apart from that its as book.

What is the preffered diff to use?
If youve got a book live axle chassis then you'll probably need a 3.54, although it depends on what tyre size you go for.

What is the best prop to for a BEC??
There's nothing suitable from the scrapyard without serious mods because you need a long 2 piece prop with centre bearing which you wont find on a donor car. Bailey Morris amongst others will make up a prop with a TRT but might set you back best part of £300 (or just over £200 without TRT which is desirable but not essential)

And last but not least, what 0-60 is possible with a superlight BEC with 140-150bhp
Even a 130bhp blade will do it in 4s with practice, an R1 high 3s and a busa a smidge quicker again, so all plenty quick enough. IME the higher power BECs only really gain significantly on the blades etc once you get above 80-90mph, and even then the gap isnt as much as you would think with a 50bhp handicap.

Thanks Chris

The TRT sounds like a great idea! Do you find when down shifting the rear end momentarily can lock? Or is a smoother cluch action needed to iron it out??

Paul

We've done a few hard drives (eh-hem) and haven't experienced the momentum locking up the rear's. Prepare beofre you go into the corner and everything should be easy enough... BTW our ZX12R engine can hit 4s and that's without really trying... it's scary when you get down to those figures

Wise choice with dumping the car engine - old ship's anchor - make no mistake!

Keep the revs up or blip the throttle on the downchange and you shouldn't lock up so much. It works on the bike anyway.

I got my brand new prop with TRT, centre bearing and sliding rear section for my licve axle for £160!!!

Dunning and Fairbank - Leeds.

Great service and they deliver to.

If you're definately going the bike route, you can leave the tube that goes right across the chassis at the footwell ends without cutting the centre section out (as per the car version).

You'll also haveto work out how you will fit the centre bearing. I have gone as per MK with a vertical plate on the drivers side of the tunnel near where my shin would be.

If I was to start my chassis again, I would also move the engine back slightly and reduce the passenger side cockpit length as you will end up with about 8-12" at the end of the passenger footwell that will never get used and you could have had the engine further back.

Hope that helps,

Pat...

Thanks Guys!!

Great advice

Paul