I tinker with single cylinder 4-stroke (kart) racing engines a good deal. Flywheel design for optimum weight has always amazed me. Does anyone have formulas for optimizing the design? It's more than just saying "x" pounds is best, because the actual shape of the flywheel, width and thickness of the rim, and how close the mass is to the center of rotation matter also. Can anyone recommend a good book? I know I = 0.5m*r^2 is good for the MOI, but that's far from the total equation. Designing an engine from scratch.