A friend was getting out of nitro planes into electric stuff and I got some stuff from him. With the stuff was an Evolution engine on a 40 size plane. The engine was filthy so I gave it the old antifreeze-in-a-crockpot treatment, oiled it up, and flew it today. It was an absolute delight, performance wise. Impressive would be the word. The only bad thing about it is that nowhere on the engine does it list a size. I assume it is a .40 to .55 size judging from the plane it was on, but I am not sure. My question is for you Evolution enthusiasts out there: how can I determine the size of the engine?

Hi there,

On my little .36 the size is stated on the side of the head on the cooling fin. If I am not mistaken, it is the way on the whole glow range.

Hope this helps,
Cheers.

I ran into the same thing and looking at pictures of engines on line I determined it to be a 45 . It was not stated on the engine.Like yours it runs great both low and high end.Good luck

The 46NT has a 46 on the cylinder head sides.

The .455 TPS has an 'a' on the sides of the cylinder head.

Both are good engines and have a lot of power. The 45, 46, and 36 need the OS A3 plug. You really lose a lot of power without this heat range. If you have a Tower's muffler, put it on your 45. More power there.

Thank you folks. Mine has a stylized "a" on the side of the head. I assume that means it s a .455TPS? What does that mean?

Trainer Power System. It came with a flywheel and a 3 bladed prop. You could gain more power by removing the flywheel and installing a prop drive hub and using a 2 blade prop.

DUH!!!!! Thank you. I knew it was the trainer system thing and even got the flywheel and three bladed prop with it. It just didn't occur to me that is what "TPS" meant. I also got the regular thrust washer in a sealed bag. I will be removing the flywheel and using a two blade prop in the future. I also have a couple Tower mufflers. One of them might fit. This might turn out to be a good find. The engine was gummed up from non-use, but the piston was still bright and shiny. It has not been run much.

The 3 bladed prop is lousy. It pulls okay but is very heavy. I tried one on another engine and was an underachiever.

Mufflers for the OS 46 will fit the 45 and 46. They give a big boost in power. The 45 is an excellent engine.

Yes, I was very pleasantly surprised by this engine yesterday. It was mounted on an old high wing trainer looking thing and it was rolling like a sporty plane. I just replaced the flywheel with the regular thrust washer, put a 2 blade prop (11 X 7) on it, and a Tower Hobbies .46 muffler. It certainly sounds different. I am anxious to get out and see what it will do.

A fellow flier at the field was admiring that three blade prop yesterday. Next time I go out, I will make it his.

Don't forget the A3 plug. W8YE told me to use one of his hotter plugs one day and WOW.

I think these engines are one of the best deals out there. If you get your low speed set right it will idle for almost forever with good response when you hit the gas.

I will try an A3 and see how it works after I try the changes I have already made. If you make too many changes at one time you don't know which ones helped or hurt.

It would be interesting to tach the glow plug change.

Yea, that's a damn fine engine once you remove all the TPS crap.

BTW, you can just press the weighted collar off the existing thrust plate, but if you've already got the regular one, you can just swap them.

I was not aware that the weight could be pressed off. It'a good to know. Will keep it in mind.