RE: So, what about this new 60 in a 40 size Evolution?
I would think it is an attempt to out do the OS .55AX. I have 2 of those and also a JBA .56. Both of these engines run well and both turn about the same rpm on sport props with stock mufflers. The OS .55 responds very well to a Jett muffler, gaining 1500-1700 rpm on 11-7 & 11-6 props. The JBA only gains a few hundred rpm.
I also tried the Tower and OS mufflers on the JBA and both were about 500 less than the stock JBA muffler.
If the Evo 60NX turns like the OS & JBA and responds to a pipe of Jett muffler, it ought to be great with one caveat. The glow Evolution engines are made in the same factory as the Magnums. I certainly hope the carb is better. I had 3 Magnum .52XLSs. They were top end screamers, but the mid range was poor. I have also fixed my Evo 100, one of my Tower .75s and a buddy's Evo .61 with SK 90 carbs, which have a great mid range.