[Daver]

Van's advertised performance numbers indicate they were obtained with a "fixed pitch propeller".

I wonder what pitch they used; climb, cruise or something in between?

I guess I could just e-mail Van's but I thought someone here might have a clue.

thanks!

Dave
wings finished
fuselage on its way

 

[airguy]

And yet they have a CS prop on the demonstrator 9A - interesting. I'll be running a CS prop for certain.

 

[Build9A]

Sensenich O-320, 79" pitch

Van's advertised performance numbers indicate they were obtained with a "fixed pitch propeller".

I wonder what pitch they used; climb, cruise or something in between?
I guess I could just e-mail Van's but I thought someone here might have a clue.

Dave
wings finished
fuselage on its way

Dave: Here is the propeller that I ordered for my 9a 0-320.

Sensenich O-320, 79" pitch
Part Number = PROP 70CM6S9-0 (79)

It has an RPM limit of 2600 rpm. I meet the gross weight climb numbers published by Vans (1400fpm) easily. I don't quite get the 1900fpm solo weight climb as advertised. I can squeeze out 1750fpm. Not bad. I think my prop is a "cruise prop" but someone else might review this and confirm it. It was the recommended prop by Vans for my configuration, if I wanted a fixed pitch and wanted it certified.

My cruise numbers are right on Vans advertised figures. I was surprised because I thought that their numbers would be .....with a professional test pilot and a professionally built and balanced airplane. Nope, you and I can reach their numbers, they are very realistic, unlike many kit advertisements.

With that said some folks have been getting good performance with catto props and speak highly of them. I am satisfied with the Sensenich and you get used to watching for the 2600rpm limit. Wish it wasn't so sometimes but I still like it.

 

[tc1234c]

I also ordered my Sensenich fp propeller from Van's. I believe it is a cruise propeller. My model number is:
70CM7S9-0-79. (vs 70CM6S9-0 (79) of Build9A's).

Flying high, unless in a descend, I can never get my propeller to turn at 2,600 rpm. At 8,000' full throttle I get 2,500 rpm and cruise at 156 kts. At lower altitude full throttle I can get 2,600 rpm and 164 kts. My airplane is on the heavier side.

 

[Coinneach]

I also ordered my Sensenich fp propeller from Van's. I believe it is a cruise propeller. My model number is:
70CM7S9-0-79. (vs 70CM6S9-0 (79) of Build9A's).

Flying high, unless in a descend, I can never get my propeller to turn at 2,600 rpm. At 8,000' full throttle I get 2,500 rpm and cruise at 156 kts. At lower altitude full throttle I can get 2,600 rpm and 164 kts. My airplane is on the heavier side.

With those numbers, it sounds more like your prop is biased towards climb. What climb rate do you get at gross?

 

[Daver]

fp props

I thought a cruise prop would tend to limit top RPM (static on the ground and in cruise).

AND, a climb prop would be able to overspeed the engine at cruise.

Well, that just goes to show you how little I know about props. That's why I always ask questions.

It sound like Jack, with his 79" pitch, is getting performance numbers similar to Van's advertising. I'm guessing a 79" prop would be considered a cruise prop.

Dave
awaiting the arrival of my slow build -9A fuselage

 

[647jc]

According to Sensenich, prop pitch for an RV9 / RV9-A with a O-320/160 HP Engine:

Standard 79"
Climb 78"
Cruise 81"

Van recommends a 79", probably for best all around performance.

Also according to Sensenich, for a 150 HP engine, subtract 1" from all the above values.

http://www2.sensenich.com/direct/vans.htm

 

[tc1234c]

Now I see that my propeller is a standard one, more to the climb side than the cruise side.

Coinneach: I did not record my climb performance. I usually climb out at > 100 kts and > 1,200 fpm. With the recent cold weather, the climb performance is definitely better. I also can climb at much lower air speed and still keep the engine cool.

I took the advise of Mike Seager to set the idle low (550 rpm) in order to land the airplane easier. With a fp prop, at 650 rpm idel, RV9 does not want to come back to the earth ("it will float to the next county before touching down." MS). In my setup, my throttle cable (Van's standard issue) has a limited throw (discussed by others in another thread) and my carb is not wide open when the throttle control is pushed all the way forward. So at 8,000' I don't really have a wide open throttle or 75% power. This definitely reduces my cruise speed. At take off my propeller is turning at less than 2,300 rpm. I do have an engine monitor and it gives me percent power readings. However, it is based on the engine performance table entered by me. I have no idea how accurate it is. So my numbers can only provide you with a general reference.