I'm in the process of ordering a Whirlwind 300 series 3 blade propeller for my RV-4 (1990, standard length gear). When I bought 15 years ago and it had a cutdown 73" Hartzell (HC-M2YR-1BF-F7666) propeller. It was big, but I never had an issue with it. In 2018, it went for a reseal/repack and the Hartzell authorized service center suggested taking it down to 72"s which they did.
In talking to Hector at WW, he recommended a 72" 300 series based on my engine (Lycoming IO-360-B1E). He said a 70" would work, but might be pushing the limits of the propeller. The largest engine they recommend for the 70" is a IO-340 (9.6:1) which is right at 180hp like my Lycoming.
Not being an engineer I have no way to know whether 72" or 70" really makes a difference. Is there a noticeable performance difference? Is the extra 1" of prop/ground clearance significant enough to warrant the smaller prop? Probably the simplest question is what are other RV-4 owner's with the original length land gear flying? And why.
Any advice would be greatly appreciated.
Scott
In talking to Hector at WW, he recommended a 72" 300 series based on my engine (Lycoming IO-360-B1E). He said a 70" would work, but might be pushing the limits of the propeller. The largest engine they recommend for the 70" is a IO-340 (9.6:1) which is right at 180hp like my Lycoming.
Not being an engineer I have no way to know whether 72" or 70" really makes a difference. Is there a noticeable performance difference? Is the extra 1" of prop/ground clearance significant enough to warrant the smaller prop? Probably the simplest question is what are other RV-4 owner's with the original length land gear flying? And why.
Any advice would be greatly appreciated.
Scott