Hey guys, I've noticed oversquare engines tend to rev higher and I was wondering. If I was want to make a larger displacement engine with a similar torque curve, would the same ratio of bore/stroke result in a comparable peak RPM levels. To clarify if I was to make a 331 (bore4.125, stroke 3.09375) could i get the same torque curve (not numbers just shape) and same redline as a chevy 302 (bore 4, stroke 3) because the ratio bore/stroke is the same? Any help would be greatly appreciated.

Note: Some figures for the 331 have been rounded to simplify the post.

Interesting question. I would think the rod length would have to grow as well to keep the rod/stroke ratio the same. Long rods work better in high RPM engines, short rods build torque. you would need a rod length of 5.878 to keep the same rod/stroke ratio. I think piston speed is what determines max rpm and piston speed goes up with any stroke increase. This assumes the valve train can keep up with the bottom end. The piston has slower rates of acceleration and decelleration with the longer rods. Have fun