You touched on some of the recent history of how that engine was advertised. It was called a .40 engine for a long time, and I have no idea why. It is indeed a .455 displacement engine. It is well worth the money as it has a tremendous amount of power. It is ridiculously easy to tune and stay running.

I tried quite a few props on mine, and the APC 11x7 was about the best for all situations. You could put on a smaller pitch if you wanted more vertical pull. The Master Airscrew series was disappointing compared to the APCs. Zinger 11x7s were worthless, imo.

One thing about those Evo 3 bladed props. Balance them!!! I have 4 of them, and they all are way, way out of balance. Mine all have one blade lighter than the other 2. You know how everyone says to sand a little, balance, sand a little more, etc? Well, on these props you get out the Dremel with a sanding drum and grind away a lot of plastic before you can get close. Forget sanding small amounts or you will at it for days. I was a beginner when I landed one evening and 3 engine mount bolts were shaken out. Two were stripped. I didn't know about prop balancing then.

When you get tired of your trainer, put the Evo .45 on your next plane and it will surprise everyone at the power it has. Just take off the flywheel weight and prop it good.

I hope to fly mine again next week. I'll post my RPMs, and how well it flew with a Tower muffler.