'Undersquare' vs. 'Oversquare' pistons?? Need Help!!! hi I'm a high school student doing a little research on the performance applications of oversquare and undersquare pistons in car engines... btw, oversquare = pistons with bore:stroke ratio > 1 undersquare = pistons with bore:Stroke ratio < 1 I've found that several sports models tend to have oversquare pistons, while the slower and rather heavy duty cars prefer undersquare pistons. Could someone explain the mechanics of this...? I've heard that, for every cubic centimeter or inch of displacement volume, oversquare engines can operate at much higher speeds than undersquare ones. Does this necessarily imply more power, if so how?? I mean if we were to create a 400 cc cylinder (not engine), and decide whether to make it undersquared (eg. bore= 7.14 cm, stroke = 10 cm, volume = 400cc) or oversquared (eg. bore = 9.21 cm, stroke = 6 cm, volume = 400cc) and want maximum power out of it... would we prefer the oversquare design? Is this simply because it can 'rev to more RPM'?? Please note I'm only concerned about the performance aspect of this comparison. Could someone kindly explain this to me in detail? Cheers!!