I am setting up a plane for a new flyer and he is looking for an engine for a tower uproar. Can anyone tell me the difference between the .46nt evolution engine and the .45 evolution power system? Looks as if the .45 is heavier but didnt know any other differences. I wouldnt think that .01 displacement size would mean much.
Thanks
jeff

There's not a lot of difference in the way they perform.

Being as it is going on an uproar I would get the NT.

Id stear clear of evolution i have had nothing but trouble with my engine

I have always flown O.S. myself but I was looking at the evolution because the .46nt had a ball bearing crank for a price of $89 and the os engine with a ball bearing crank was $129.
Thanks
Jeff

Jeff, you have a private message!

The Evolution engine needs a "Hot" plug to accelerate well. The original plug runs well as long as it lasts. But your new plug must be of a hot heat range for the engine to run well.

The needle valve limiters tend to be more trouble than they are worth. Most people defeat the limiters to get the engine to run correctly.

After all this - they run very well.

Interesting that you would have a hard time with the Evolution engines. I have a few and the first one was a 45 trainer system that I picked up as a lark to see what they were like when they were first introduced. It was put on a friends 3d model and has used 30% Cool Power heli fuel[as he refuses to carry more then one fuel and he flies helis predominately.]
That was over 3 years ago and to this day it is still a one flip starter with a consistantly low idle and a very precise throttle. No bearings have worn out and the prop is an APC 12.25X3.75.Plug is an Enya#3 HOT .
As others have pointed out the needle valve limiter was quickly discarded but that was the only'tweakin' done to it.
I've just started using the 36 and can only repeat the comments that I've made above.
Dennis

I think the reason the trainer engine is heavier is because it has a rather large flywheel on it.
I've got the trainer engine (.455 ) that I took the flywheel off of, and it runs very much like my 2 .46NT's

The .46NT with a GMS/Tower .46 muffler is a nice, powerful combination, with either a 12x4 or 12.25x3.75 APC.

I Have the Evolution trainer system on a Four Star 40. I took off the flywheel and put an APC 11x7 prop on it. It runs very well. There is plenty of power for verticals. It moves that SIG around pretty fast. I liked the engine so much I bought another Evolution .46NT this time around.

I have had OS, Magnums and now the Evolution engines I think they are good. I also thinking about their .52 for a forty size Ugly Stick
I have.

Good luck
Frank

I believe it was "RC Reports" magazine that did a review of the two engines and they found it strange that Horizon would offer both engines when the trainer system engine made more power and was a little more user friendly. Do a little research and you may find the article.
The EVO engines that I have actually used ran just fine and had no problems other than they needed a long 4 stroke type glow plug sometimes to make the best power. From the recent adds it seems the photos of the newer versions have a more upright glow plug.
Fred