Yes they are the size of a .46, and yes they are as powerfull as a full size .60, but only with the smaller props. They are awesome in small fast planes, and really come to life with aJett muffler (Evolution performance muffler) or pipe. They will turn a 10-8 well over 15,000 rpm. The stock muffler supplied with engine is useless in my opinion since it is to small, and runs horibly with it. That said, they are screamers, and will really impress you with it performance.