I have a .91 SP in a 8' Lanzo Record Breaker and I love it. I built the plane to be a test bed and showcase for the engine. It became a perfect match. The gear train was very tight and noisy at first especially when the engine was cold. The more I use it the better it sounds and runs. I watched the crankcase vent very closely to see how much actual metal was being polished off and discharged during the break -in and it was surprisingly clean.

It tunes as easily and reliably as any other engine I have ever had. After about 15 flights using a ten ounce tank it is still very tight when cold (I have been flying in 30 degree weather )but after it has been started once during the day it is a simple one flip hand start engine. Mine will run on the rich side and turn a Dynaflight 18X10 steadily @5500 rpm with 10% synth./castor blend @ 4500'.

Mine has no cowl and I haven't flown it when the temp has been above 70 degrees or so. If the engine design were to be at fault for any cooling issues my guess would be the fact that there must be some air gap between the cylinder sleeve and the engine case since the fact that it floats on bearings. Also in effect the cylinder "head" has no fins at all and mostly must use the prop. shaft and washer as a heat sink.

I had become bored of them and traded all of my four strokes when I got this one. I have really enjoyed the RCV. At the first I thought it might be a gimmick but I now believe it is a serious, practical, user-friendly engine. Long term "torture" test to follow....

Take care, Cliff