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I have the ground adjustable prop. I'm just wondering about the experiences of others. I started with a pitch of #2, but was not getting anywhere near the static RPMs I should have (AeroVee), so I immediately adjusted down to the finest pitch: #0. That's where I've been running for 70 hours now. But in cruise, WOT, I never see over 2,950 RPM. I had someone make a new adjustment pin so I can make the pitch even a little finer, but I haven't tried re-setting it yet. Waiting for warmer weather! I'm hoping that making it a little finer will get me up to around 3,200 RMP, but obviously the prop wasn't meant to be set finer than #0.

Not getting the full RPMs could be the engine not developing full power, but the engine runs great otherwise.

Again, just wondering what others with the AeroVee and ground adjustable prop are experiencing.

Thanks,

Mike,

I got the same prop and ran into the same 'problems'… What I did was make small pins. Of course, the limiting factor is the diameter of the inner guide pin hole. So, I started with that diameter (don't have the figures with me). When that didn't get me much of an RPM increase, I went smaller. I made a bushing to go in the inner guide pin hole and that allowed me, of course to go smaller on the guide pin. I finally got down to a pin that pitched the prop pretty close to the Sensenich wood prop that I had on it. But then, the performance numbers were the same as that prop…go figure :lol: Oh, and the wood prop was smoother running.

It was fun to play around with it but it was a trade off, good RPM for T/O and cruise suffered. Not so good RPM on T/O and cruise speed went up…. It really was made for the Turbo, and that's where it shines. I now use the Number 2 pin and get about 2975 RPM on T/O at 40" MAP then phenomenal cruise speed (for an Aerovee). I haven't tried any other pins with the turbo yet. Once I'm comfortable with the turbo I'll start playing around with different pitches.

marsolgp wrote:Mike,

I got the same prop and ran into the same 'problems'… What I did was make small pins. Of course, the limiting factor is the diameter of the inner guide pin hole. So, I started with that diameter (don't have the figures with me). When that didn't get me much of an RPM increase, I went smaller. I made a bushing to go in the inner guide pin hole and that allowed me, of course to go smaller on the guide pin. I finally got down to a pin that pitched the prop pretty close to the Sensenich wood prop that I had on it. But then, the performance numbers were the same as that prop…go figure :lol: Oh, and the wood prop was smoother running.

It was fun to play around with it but it was a trade off, good RPM for T/O and cruise suffered. Not so good RPM on T/O and cruise speed went up…. It really was made for the Turbo, and that's where it shines. I now use the Number 2 pin and get about 2975 RPM on T/O at 40" MAP then phenomenal cruise speed (for an Aerovee). I haven't tried any other pins with the turbo yet. Once I'm comfortable with the turbo I'll start playing around with different pitches.

Interesting about the turbo, since Sonex specifically says never to use the adjustable prop with the turbo. I don't know if maybe it was because the adjustable prop is rated for only 80 hp.

Actually Sonex ran this ground adjustable prop for quite a number of hours, on the Turbo Aerovee…. they did have some issues and recommend the two fixed pitch props, that they now sell, instead. If you check the paperwork that came with your Grd Adj Prop, it is, in fact, rated for 100HP. I guess that's the nice thing about EXPERIMENTAL, we can experiment.