i am a helocopter engine mechanic for the military, the bird i currently work on is a CH-47 D, A single engine weighs approx. 860 lbs, without the fuel or tranny you would need for the reduction gearing, ( The rpm is about 29,000) the upside is it produces about 4,700 constant shaft HP!!! talk about all the power yu would ever need!! The only two drawbacks i can see it the amount of noise you would have in the cab, oh yeah the price, about 1.3 mil per engine, thats without all the fuel management! HAHA