Repitching Sensenich

[litewings]

Does anyone have any feadback on repitching props on thier plane. Looking for RPM changes at static and cruise for inch of pitch change on the prop. The particular plane is a RV 7a with a 180hp XP0360. Has the recomended Sensenich fixed pitch prop and the cruise is well below the standard numbers.

[13brv3]

Greetings,

I originally installed a Sensenich 72x85 on my earlier RV-8, and later repitched it to 87. This was a stock Lycoming O-360-A1A from Van's, but with a Lightspeed ignition, and Ellison TB.

The FP Sensenich was just a few kts faster than a friends CS (same engine and mods), but of course wouldn't keep up in climb.

Below are some notes from my flight log:

10-25-01 / 1.4 hrs / 75.9 total

Did some cruise testing of the re-pitched prop. I made a N, S, E, and W run at 8500 feet, and 13 degrees C. This was at full throttle, mixture leaned for max RPM, which was 2720 RPM. The numbers are- N- 176 kt, S- 182 kt, E- 201 kt, W- 157 kt. This gives an average of 179 kts, or 206 mph for max cruise. Of course this is 20 RPM over redline.

10-24-01 / .2 hrs / 74.5 total

Installed the re-pitched prop, and took it around the pattern a couple times. Static RPM is now 2025, so I lost 75 RPM by going from 85? to 87? pitch.

10-12-01

Measured static RPM with the 85? prop. It?s 2100 at full throttle, and full rich mixture.

[penguin]

I have just re-pitched my 77" prop to 79" for a 160hp O-320 powered RV-6A, cost was $150. Static reduced by 40 or 50 rpm, cruise rpm was far too high (could not use full throttle after cahnging from 150 to 160hp), so don't know exact drop due to repitch.

Pete

[gmcjetpilot]

Some prop shops will do it, but I say have Sensenich do it. Sam Buchanan has an experience with this http://home.hiwaay.net/~sbuc/journal...gs.htm#repitch

G