I have this engine in my RV4 and love it. You'll want to take advantage of using a C/S prop with it even though some of my RV4 brethren prefer F/P on the -4. I am very happy with the performance.
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Mike JAMES AIRCRAFT.com
Flying - RV8 Hot Rod "Drone Killer"
Flying - RV8 "Look'n Good"
RV4 - FAST & FUN! Rebuilt, Flown, Sold
RV-7A Built, Flown, Sold