Originally Posted by
Fiesta_Jed
when you say square do you mean the bore/stroke ratio?
Yes mate.
Its there any advantages/disadvantages of an engine being square, over suare or under square.
Its very application specific, often people will make their engine a longer stroke to increase capacity for example, and as a result parhaps end up with slightly less power per cc but still more power as they have more ccs.
Basically as a general rule of thumb, for a really revvy engine you have a bigger bore than stroke, to prevent piston speeds getting too high, and to increase valve area.
But an evo engine has a longer stroke than bore, and a YB has a bigger bore than stroke, which totally contradicts what I just said of course, as the evo engine revs far better than the YB.
But there are LOADS of other factors that are the reason why it looks like it doesnt work how I just said.