Prop "Feel" and tuning

[OverTemp]

OK.... so I just got a new prop for my DA-100 and I'm wondering if my observations are normal.

I was running a Menz 27x10 and I got a Mej 28x10... I was told thay are about the same load as a Menz 27x10.

The Menz seemed to get much more RPM in the lower part of the throttle travel and the last 1/4 stick had almost no power change. Tuning was difficult... I never really saw much change in peak RPM with needle adjustments.

The Mej seems to require more throttle in the lower power range to do the same thing as the Menz... it seems to take a bit more from engine to turn the prop at the lower RPMs. Result is that the throttle feels more linear... there are definite and almost equal RPM changes all the way up to full throttle. The peak RPMs are down a bit (about 6,300 right after landing from a hard flight... almost 90 degrees and VERY humid... I would expect about 6,500 cold). I see a definite change in RPM with every small tweak on the high needle. I leaned it to about 6,300 (hot engine) and can probably go in more... my needle was a little more that 1.5 turns out to start with, now I'm back in to 1.5 turns and RPM was still increasing when I stopped turning it in. The low needle seems like it needs to be much leaner than it did with the Menz prop.

Overall, uplines seem stronger and braking is better. The plane slows down for landing much easier... I could salvage landings that would have been a go-around with the other prop.

Let me know what you've experienced!

[1bwana1]

I switched from a 27 X 10 wooden prop to the Menjslik 28 X 10 on my 100cc YAK and it made an incredible difference. My observations are the same as yours. The 28 X 10 is the way to go, at least for IMAC.