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Which Propeller?
Posted: Thu Oct 17, 2019 11:31 am
by 8434
Hi Folks,
My prop is up for inspection next year and I have been contemplating getting it re-pitched from 52 to 50 to improve STOL performance. Its a McCauley CM7152. I started doing some research and found there are other options but none that I could find with STCs, so what is everyone else running? Has anyone put a Catto prop on? What about ground adjustable?
Marshall
Re: Which Propeller?
Posted: Mon Apr 13, 2020 4:03 pm
by klyde sessna
A 7148 is standard. A 7150 is cruise. You are probably way overpitched.
Re: Which Propeller?
Posted: Mon Apr 13, 2020 4:05 pm
by klyde sessna
A 7146 is proper pitch for a climb prop..
Re: Which Propeller?
Posted: Tue Apr 14, 2020 7:22 am
by 6643
"A 7148 is standard. A 7150 is cruise."
"A 7146 is proper pitch for a climb prop.."
These statements are true if you have a C85 installed. If you have a C90, the 7152 is the "standard" prop. 7150 would be considered a climb prop.
Look at the type certificate for a list of approved props for your engine. Choose a pitch that puts your static RPM near the upper limit for best climb performance. There are a few STCs out there, but not many, that I'm aware of.
Re: Which Propeller?
Posted: Tue Apr 14, 2020 11:38 am
by 6795
I have the C-85/O-200 Crank conversion swinging a Sensenich 76AK-2-44 prop.
Works well!
Re: Which Propeller?
Posted: Tue Apr 14, 2020 1:31 pm
by 6643
Moved to Technical Discussion.
Re: Which Propeller?
Posted: Tue Apr 14, 2020 9:04 pm
by 1125
Did the overhaul with Millineum cylinders, ASS crankshaft mod and found the 71- 46 pitch would overspeed upon takeoff. Took it to Maxwell in Minneapolis, discussed the issue. They repitched it to 71-48. The ground run RPM (per type certificate data sheet) was right on, the airplane is a good performer. Remember to read the TC data sheet, there is a lot of good info for the aircraft airworthiness in there. It's all in the reference manual our club members put together years ago. Thanks to them, we have a great resource to keep our airplanes flying.
Re: Which Propeller?
Posted: Sat Apr 25, 2020 9:03 am
by 8475
1125 wrote: ↑Tue Apr 14, 2020 9:04 pm
Did the overhaul with Millineum cylinders, ASS crankshaft mod and found the 71- 46 pitch would overspeed upon takeoff. Took it to Maxwell in Minneapolis, discussed the issue. They repitched it to 71-48. The ground run RPM (per type certificate data sheet) was right on, the airplane is a good performer. Remember to read the TC data sheet, there is a lot of good info for the aircraft airworthiness in there. It's all in the reference manual our club members put together years ago. Thanks to them, we have a great resource to keep our airplanes flying.
Where can I find a copy of this alleged reference manual?
Re: Which Propeller?
Posted: Sat Apr 25, 2020 9:29 am
by 2066
8475 wrote: ↑Sat Apr 25, 2020 9:03 am
1125 wrote: ↑Tue Apr 14, 2020 9:04 pm
Did the overhaul with Millineum cylinders, ASS crankshaft mod and found the 71- 46 pitch would overspeed upon takeoff. Took it to Maxwell in Minneapolis, discussed the issue. They repitched it to 71-48. The ground run RPM (per type certificate data sheet) was right on, the airplane is a good performer. Remember to read the TC data sheet, there is a lot of good info for the aircraft airworthiness in there. It's all in the reference manual our club members put together years ago. Thanks to them, we have a great resource to keep our airplanes flying.
Where can I find a copy of this alleged reference manual?
Click "Store" (above), then "Cessna 120-140 Marketplace" -- "Reference..." + order.
Mac
Re: Which Propeller?
Posted: Mon Apr 27, 2020 4:59 pm
by 8475
2066 wrote: ↑Sat Apr 25, 2020 9:29 am
8475 wrote: ↑Sat Apr 25, 2020 9:03 am
1125 wrote: ↑Tue Apr 14, 2020 9:04 pm
Did the overhaul with Millineum cylinders, ASS crankshaft mod and found the 71- 46 pitch would overspeed upon takeoff. Took it to Maxwell in Minneapolis, discussed the issue. They repitched it to 71-48. The ground run RPM (per type certificate data sheet) was right on, the airplane is a good performer. Remember to read the TC data sheet, there is a lot of good info for the aircraft airworthiness in there. It's all in the reference manual our club members put together years ago. Thanks to them, we have a great resource to keep our airplanes flying.
Where can I find a copy of this alleged reference manual?
Click "Store" (above), then "Cessna 120-140 Marketplace" -- "Reference..." + order.
Mac
Mac, thanks. I tried to purchase the book, but the checkout code is behaving oddly. Unable to view the qty in the qty box and when I go to check out, the site just hangs. I've tried both Firefox and Edge.