I've seen some crazy numbers both in torque and HP within the go cart/tractor pulling community I wouldn't be surprised if these engines worked well as advertised...They sure look promising... Make sure you ask all the right questions...Some of those would be what routine maintenance needs performed ?How many hours before other items need attention? How many hours typically accrued before it would need a complete teardown/overhaul ??? And lastely will they sustain long,high RPM runs that happen in our use ???