piston

if you do have so much experience building motors, then you should be well aware that compression-induced detonation and preignition caused by a hot part in the combustion chamber are 2 totally different things.

Having a smooth combustion chamber does nothing to 'help' higher compression....as to the 'angles and edges' you talk about.....most everything uses smooth, flowing shaped not prone to hot spots that can cause pre-ignnition....if you do get a carbon deposit or something thats glowing and causing pre-ignition, the compression ratio wont do a thing to help it, its just gonna pre-ignite no matter what. If you could just smooth out the chamber and run super high compression, why dont we have superbikes with 15:1 ratios?

I'm not calling you an idiot, but you obviously need some help with the differences between pre-ignition and detonation. And I've been building bike motors for 10 years now, with many race winners using motors I built. As to the smoke and mirrors, I dunno where you got that from as everything I have said is fact.

Heh I've been playing with motors since I was kid everything from lawnmowers radio controlled car motors to big cars this idea that hot spots in the combustion chamber causing predetonation is true but not on these small 4 stroke motors. the compression ratios do effect detonation but little hot spots never. I've played with combustion chamber like I said before and no differance was noted . I've also played with the dome shape of the pistons Hieght ,progressive edge and squash zone no differance . these theorys just don't apply with little 4 strokers from what I have seen .



No pissing matches needed just facts . but like I said these little 4 strokers are being built bigger and better than lets say 10 years ago so we should keep the lines of comunication open and the R&D rolling.



there is still alot we don't know about these little guys so back to the drawling board we go untill we figure it out

this isn't extremely accurate but it will due. this is a chart out of an atv magazine. they were doing a test over octane. they found out that more important than the octane of a fuel is how fresh it is. in a bored out 250r with 14:1 compression they found that a lower octane fuel that was two weeks newer performed much better than the higher octane. if you want me to be more specific i can reread artical. both fuels used were race fuel from vp. if you can get away with a lower octane fuel than do it. i would always recommend vp though expecially if you can afford to spend the money on it. i conclude by saying that if you use a lot of fuel in a week or two then get vp. if it is going to sit then you are better off saving your money. i am not looking to get into a fight either. just wanted to make a point for whichever side wants to use this info.