Big Bang 4 cylinders

[bdwoody]

I was wondering if any one has tried or is trying a big bang 4 for saloon car racing . the bike boys have got a few more HP out of little 1000cc bike engines by going down this route does it work in cars?... woody

[graham bahr]

i thought the reason bike were going big bang, wasnt for more power but because it gave the tyre more time to recover between power strokes ( it made 4 pots more like the the V twins) and thus gave the riders more feel for what was happening with regards to rear tyre grip, but i think now bikes have gone down the traction control route i think the big bang stuff largely irrelavent now

[Chris Griffin]

TVR AJP V8 is (I think) the only car engine I'm aware of.

[trikesrule]

Graham your absolutely correct. The speedway team I used to be with went over to big bang 2-strokes then with the advent of traction control went back to what they used to run. Can't see any advantages at the moment using big bang in a car - perhaps I can't see the firewood for the trees........trikes

[graham bahr]

i would imagine big bang in most engines creates bigger stresses and vibration for things like crank cases to deal with, so probably not a good idea from that front.

i suspect in the case of a V8 it might be a way to achive a much simpler, therefore lighter and stronger crankshaft design

[bdwoody]

Dont ferrari v8's use this form coz they always sound a bit 4 cylinderish to me or have i gone tone deaf in me old age!..

[graham bahr]

ferrari's have whats called a flat plane crank woody, the crank pins are are all 180 degress apart as opposed to a normal v8's 90

the crank design means they are effectively two 4 cyl inline engines on a common crank, it makes for a simpler crank, but more importantly allows a proper tuned exhaust manifold to be fitted, that connects the cylinders in the correct way to achive best scavaging and maximise power.

in an ordinary V8 to get the BEST design of exhaust manifold you would need to connect cylinders from opposite banks which is impossible in most cars unless you have a GT40 and can go over the top to join the banks.

that said a typical v8 4 into 1 manifold or header to speak "american" design does a pretty good job

[chunder]

Didnt Honda ( the developers of the 2 stroke big bang theory in 91/92) come up with something for Indycars, or was that VTEC that never worked!

And youa re right about stresses, Honda and especially the otehr teams blew engines up regularly as they fought to catch the Honda desiegn up in 92, but usually in testing

The new 4 stroke engines also use similar technology, they use a kind of long bang idea to again hold the pulses close together to help with tyres, but the advent of TC (sadly) in bikes means this is maybe not so important as I dont think the new Ducati missile uses that stuff, sounds like a good old V4!!