Fixed pitch for 9A?

[avi8tor50]

NOT looking to stir up the FP vs CS debate. I've flown both in Cessnas. I understand the advantages of the CS but cost is an issue and, for me, simplicity is important.

OK-Having said that. What I would like to know is what speeds 9A drivers with O-320 160 HP are getting at what RPM. I've never run my a/c's at "balls to wall" and would not be doing that in my 9A. So tell me, what are you showing for indicated airspeed at different RPM's in an a/c at 1100 lbs or a little lighter.
My needs for an a/c are for cruising at 150 KTS indicated. If I can go faster that's nice but NOT a requirement.

Soooooo-you 9A drivers out there with FP O-320 160 hp:
What RPM do you need to run to get 150KTS at, say, 6000' maybe in the spring with a ground temp of say 70 degrees.

I'm not looking for a technical discussion; just some ancidotal experience.

Thanks to all for their input.

 

[John C]

The numbers I use for my 9A - O320 160 hp

The speed numbers and MAP are reasonably accurate. I used the GPS-four side speed run method to get TAS. RPM is accurate. I am not as comfortable with GPH, MPG, or % as I don't have fuel flow.

The top end speed numbers are a little less because the engine is rated at 160 HP at 2700 RPM and the Sensenich prop is limited to 2600 RPM. I have a little throttle left if I wanted to push the RPM. Each 100 RPM is worth about 7-8 MPH.

I did not correct to SL with the 189 number below so it is not consistent with the 2,500 feet table, but good enough for me.

My EWT is 1050.


SPEED: SOLO 2600 RPM
Maximum at Sea Level???????????...... 189 MPH
Cruise, 75% Power at 8,000 Ft????????.. 185 MPH

VANS numbers...................................................... 195
......................................................................... 187


Cruise Performance at 2,500?and below (Standard OAT): 3gal
TAS RPM MAP GPH MPG DIST %
181 2500 23.7 9.0 20.1 660 75%
173 2400 23.0 8.5 20.3 670 71%
165 2300 21.7 7.7 21.5 710 64%
156 2200 20.3 6.7 23.2 770 56%


Cruise Performance at 8,000?:3 gal
TAS RPM MAP GPH MPG DIST %
185 2600 21.7 8.8 21.1 700 73%
178 2500 20.9 7.9 22.5 740 66%
172 2400 19.6 7.2 23.9 790 60%
165 2300 18.5 6.6 25.0 820 55%