APC 22x10: 7400rpm
APC 24x8: 7100rpm
MenzS 24x10: 5800rpm
MenzS 26x8: 5300rpm
All readings with Toni Clark rearmounted "Piper" silencer, and intake elbow and trumpet.
Ooops.. forgot one.
3W 32x12: 4000rpm, on homemade 2:1 reduction drive.
Menz 24 x 8 - 6,700rpm.
Standard muffler, + inlet trumpet.
6700rpm on a 24x8 is quite a lot. Must be a good engine.
A friend of mine run´s 6700rpm with a MenzS 22x10, and a Krumscheid can. I have to say that the length is not adjusted other than "there about". But based on your readings it should be able to spin it quite a bit faster with proper tuning.
My own G-62 has spent the winter getting a new crankshaft installed, and while I had the engine disassembled I decided to remove some of the edges in the intake/exhaust openings, and smooth the transfer channels in the cylinder. Can´t wait to get it started to see if develops more power with those mods.
It will eventually be used on a 3,5:1 reduction drive, so I will tune the exhaust for 9000rpm or there about. That way the engine will be operating where it develops most power.
New reading from today.
A friends OOOOOOLD ZG-62 with Krumscheid tuned pipe.
APC: 24x8: 7200rpm
MenzS 24x10: 6700rpm
More ZG-62 readings.
ZG-62 with stock exhaust (twin outlet, both fed into single 15mm copperpipe exiting the cowl), carb bend and inlet trumpet.
Fiala 26x8: 6.000 to 6.100 rpm after landing. Idle around 1.300rpm, but can be lowered to 1.000 before the engine quits. Love the easy starting, and smooth idle, with the bigger props.
This is mounted on a Hostetler 1:3 scale Piper Tri-Pacer weighing in at 37lb, which will climb at an angle of around 30°.
It is a bit noisy going full power in level flight, so I have ordered a Fiala 26x10 to try to lower the rpm a bit.
This is my first Fiala prop, but so far I´m very impressed with the performance and quality. It pulls at least as well, or possibly better, than the Menz 24x10 I used previously.
Anyone else using these props?