Larry is right. More power means better climb, higher cruise in most cases and more power in reserve if needed. Mark's comments to me were not meant to say that the VW is bad, just on the lower end of the available power spectrum, for engines that match the KR. There is an old saying that fits perfectly here: "There is no replacement for displacement". Given the same setup, the engine with more CID will out perform the smaller engine.
The RG2000 may be a good engine, I don't own one so I don't know. But it will have to be run at a higher rpm to make the same torque as the Corvair, even through its gear drive, so it will surely effect engine life to some degree. Still it will be hard to knock the 3.5 gallons an hour I was burning with my first VW engine! The RV camps are going through a similar 4 to 6 cylinder transition, as many RV builders are finding the O-540 more affordable and economical to operate than the O-360. Kind of the same thing here, VW to Corvair.... Colin Rainey brokerpilot9...@earthlink.net