"Wayne" wrote in message ...
Just got the original POH, there was no CS prop on the 175 or 175
Skylark. On my plane the prop knob is in the cig lighter hole.

Really? Sorry about that. I've flown about 4 examples of the 175
over the years and half were O-360 conversions. I thought they all
had a CS prop. Oh boy. There go the brain cells :-(


They are claiming 175 HP at 3200 RPM. I believe it's a 150 HP engine
spinning at 3200 with the gear reduction rather than it's normal range of
what, 2500 RPM redline? They say 147 MPH for the 175, and 149 MPH max speed
at sea level for the Skylark.

It's the geared version of the 145 hp Continental O-300 used in the
regular 172. O-300 redline was 2700 rpm. 147mph ??? I'd say that's
pretty optimistic for the 175 unless it's going downhill :-)


The max recommended cruise is 140 and 142 MPH at 70% power and at 10,000
feet which must be full throttle and best power mixture wise.

That sounds more reasonable.

I agree that 5 HP shouldn't make much change, but the addition of a
constant speed prop should make more of a change. Am I correct? Obviously it
would make more change on takeoff, but I still expect an increase.

Generally speaking, I've noticed that a CS prop makes less of a
performance difference with lower powered installations (i.e. below
200 hp). You're right that the CS prop should allow you to take
advantage of some extra horsepower for takeoff and climb. As for how
much, you'd have to have some hp/torque charts for both installations
to get a good idea of the difference.


Where did you get the idea that it had a CD prop from the factory? Maybe
a different year?

Like I said, that was probably a brain fart. So many 175s have had
the 180/CS conversion that I probably mixed up the two.

John Galban=====N4BQ (PA28-180)