The Lycoming 0-360 C1A at 2450 rpm does not have 180 hp, I think the data plate indicates 160 hp @ 2500 rpm, my engine might have a little more but probably not a significant amount.

I have two different airplanes set up in a similar way with a 90" propeller one is in my Experimental Supercub and the other in Experimental Maule, both airplanes are around 90 mph the cub is 90 and the Maule is 95. I think the Maule is a little faster because it is cleaner design.

Thanks good to know I will have to work a little more on it.
How is the new Super Cub?
Were these props heavily re pitched?
Do you think the twist is the same as stock?
A 32" pitch at 2700rpm is 82 mph, it is physically impossible (unless in a dive) to go faster than the pitch, this is why I am confused.
I feel that if your prop has been heavily re pitched, that the 32" pitch may not be at 75% of the diameter, but rather 60-65%.

Anyhow thanks for the info, I will work on it a bit more and put out a new sheet, also with an adjustable number of blades.

I have had them re-pitched at serveral different places with the same result. These props can not be pitched this flat for a certified aircraft, only an experimental can use them (stamped experimental when they are done). I think McCaulley will only allow them to be pitched to 45 at the very most in the book, which is still pretty flat if it was used on an Lycoming O-540, it's intended engine. This propeller is very stout and because of that all the pitch change is done past that meaty point, I would have to measure it but I would guess it to be at least 20" out from center line.

I flew the heck out of the Supercub for about 6 months (170 hours) but lately it has been sitting, not because I don't want to fly it but it is easier to get in the Maule, it's at home and the cub is 25 minutes away. I also took it out last week and noticed my carb heat was not working, after looking a little closer I found the problem, the flapper is just slipping on the shaft. I hope my replacement, new and improved box is on it's way by now!

Greg

Thanks Greg,

I will work on the sheet this week end and PM you when it is done so I can give you a hard copy.

When did ya put the three blade on the Maule, that thing is a beast.
Love the videos.

Mauleguy wrote:..... I think there is a lot more to propeller performance then can be accurately calculated with math. ......

I agree. I use the old pitch x rpm /1056 formula to calculate the cruise speed. This worked out right o the money for my old 170 with it's 76-51 McCauley, but it seems to come out a bit high for my 150/150 with a 74-56 Sensenich. Less eficency from the prop due to 2" smaller diameter maybe?
Anyway, all this math stuff is fun and can be informative, but nothing tells the tale like flying the airplane. Sometimes the total is more than the sum of the parts... or something like that.

Eric