Since I'm leaning heavily toward a replica WW-I airplane, I'd love a rotac engine. But with it at least twice the cost, I can think of several thousand reasons I probably won't do that.

I've run across built VW engines, probably Great Plains, but I'm open to other brands, it's still a long way out. I really like the idea of building the engine and knowing it inside and out. I was a submarine TM/MM in the Navy so I understand the wrench turning and QA parts of this and I'm not worried about building an engine correctly.

Are the engines generally reliable? Loss of control and engine failures seem to be two big failure points for experimentals. Anything to think about or be concerned with regarding these engines?