On this episode of Engine Masters, presented by AMSOIL, all else equal, which will make more power, an iron head or an aluminum one? Aside from the obvious weight savings, does aluminum's ability to shed heat help it make more power? Or does the iron head's heat retention promote cylinder pressure and therefore more power? There's only one way to find out, and that's right here on the dyno.

On this episode of Engine Masters, presented by AMSOIL, the guys experiment with lash adjustments in an effort unleash some serious (and free) ponies. Specific engine and cam combos can benefit from loosening or tightening, leading to more power and better performance.