Who has fastest stock C-170B

[Joe Moilanen]

My 170B cruises at 140mph. I can only do it for awhile though. It all depends on altitude. Sooner or later I have to pull up...

Joe

[futr_alaskaflyer]

Checked over the phone, the prop is a Sensenich 74" diameter with a 58 inch pitch.

Curious what other flyers out there with that prop are getting as far as performance numbers, since the ones I experienced seem to be generally unbelievable My brain could have been frozen along with the rest of my body (cabin heat on the 170, as I understand it, can be temperamental) but as of now I'm still standing by my numbers

[Dave Clark]

-15 degrees, with that deviation from standard you might have been pulling a lot more power than 70%

I get about 115knots at 65% 7500ft cruise with the 180hp FWIW. I'll power it up and go faster if there is a lot of headwind but I don't do it enough to tell you what 75% would give me at that altitude. My benefit is in climb and service ceiling when loaded up, although sometimes I want to go faster. Those are the days I long for my old 330 Jake in the 195.

[futr_alaskaflyer]

Yeah, that is what I have been thinking of late, that I was basing my power setting on what that RPM would have been outputting at warmer temps, we might have been actually cruising at more like 85% or even 90%. I'm out of whack anyway on the RPM operating range with the cruise pitch on the prop.

Oh well, still a fast bird if you have lots of gas money and a good mechanic LOL I'm still learning about the 170 that's for sure.

So with a cruise prop on there what kind of degraded takeoff/climb performance will I see compared to a standard prop?

[Collin Gyenes]

Hi,

The 170 is slow all we can do is make them less slow. The best mod I did to my 170B is the Cal TWIST prop mod. It is a little faster and climb is better too. A few years ago I took off next to my friend Larry Wells '48 170 his prop was a 56 pitch my is 53 (cal-twist). I out climbed more by 300-400 ft per min. At cruse side by side I was at 2500rpm and his was 2400rpm. Are airspeeds were more 10mph differant. At full power I started pulling away. Max revs is about 2750 at low alts. I have the 170 wheel paints (for now tired of getting stuck need bigger tires) and Larry had late style 172 wheel pants.

Collin

http://www.cfiamerica.com