The Cessna 120-140 Association Forum

I have a C85 Stroker, with a 7148. I am thinking about repitching my prop to a 7146 or buying a 7146 for summer use... Interested to know what others have found in terms of performance with a climb vs standard prop. How much additional climb capabilities did it add, how much speed was lost?

If its noticeable climb difference with not a significant speed loss I'll probably have mine repitched... If there is a significant speed loss I may look into keeping a Summer Prop and a Winter Prop...

Ray

I did the stroker kit a few years ago with a 71-46 prop and it would overspeed during the takeoff run and climb. I went to Maxwell prop shop at Crystal airport near Minneapolis, explained my changes to the C85, and they repitched the prop to 71-48, which cured the problem. It also put the engine within the ground run limitations specified in the TC data sheet. I'm real happy with the performance on the runway and in cruise (90kts).

Tom O

I have the stoker, too. 85 kts in cruise at 2400 RPM. 5.9gph and a consistent 700+ fpm climb. Also, have to power back immediately on level off after a climb to prevent going past redline rpm (2575) and on climb no faster than 73 mph to prevent engine overspeed.

Ray:
What's your current static RPM? You still need to meet the limits in the Aircraft Specification, which, for the C85/McCauley combo are: not over 2300 not under 2100. If you're at least 50 RPM below 2300 you can try pitching down, otherwise I think you're as low as you can go and still be legal.

I’m going to test my static tonight hopefully as well as rpm in climb out...

I’ve had her down for a couple weeks repainting the area below pilot door that had a ton of seatbelt dings in it...