i feel the engine has 5 hp cant follow that o.s. dyno test my hyper 21 was rated 2.5 hp and dont pull like this engine or even come close my lrp z28 is rated at 3.9 hp and that engine has some torque and my brother collari .32 and my other brothers nova 528 3 port still doesnt pull like this nemesis engine or even come close and thats more proof to me than any dyno test.