I had a raptor with the TT and one with the OS. They were very comperable. The TT was just as reliable, had virtually the same power. There was not a noticeable difference. I run TT in my 60 and my boss runs OS. Same situation there. In flight, you can't really tell the diff. They run identical. I like the TT engines. Wouldn't hesitate to buy them.

Webra engines are great engines, but a real bugger to break in. Once broken in, they are one of the best engines you can fly.

I have used irvine off and on for 20 years. They have always been a cheaper engine, but run good, run strong and are reliable. My friend has a brand new one and it is very impressive. I may try a couple of them on my twin that I am building. They are great running engines. We will see how his lasts. The old ones got tired faster than some, but we ran them with high nitro.