Which Propeller?
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- 8434
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- Name: Marshall B
- Aircraft Type: Cessna 140
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Which Propeller?
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
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
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- Location: Lebanon, Tennessee, USA
- Name: Earl Tuggle
- Aircraft Type: C120
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Re: Which Propeller?
A 7148 is standard. A 7150 is cruise. You are probably way overpitched.
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Re: Which Propeller?
A 7146 is proper pitch for a climb prop..
- 6643
- Posts: 2383
- Joined: Tue May 01, 2018 7:00 am
- Location: KLCI, NH
- Name: John C
- Aircraft Type: 1946 C140/C90
- Occupation-Interests: A&P, semi-retired
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Re: Which Propeller?
"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.
"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.
John Cooper
www.skyportservices.net
www.skyportservices.net
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- Location: Pinetop, AZ
- Name: Steve H
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Re: Which Propeller?
I have the C-85/O-200 Crank conversion swinging a Sensenich 76AK-2-44 prop.
Works well!
Works well!
- 6643
- Posts: 2383
- Joined: Tue May 01, 2018 7:00 am
- Location: KLCI, NH
- Name: John C
- Aircraft Type: 1946 C140/C90
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Re: Which Propeller?
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.
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- Joined: Sun May 26, 2019 11:38 am
- Location: SF Bay
- Name: Dave Sprinkle
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Re: Which Propeller?
Where can I find a copy of this alleged reference manual?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.
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- Posts: 600
- Joined: Tue May 01, 2018 7:00 am
- Location: North Carolina
- Name: Mac Forbes
- Aircraft Type: '46 Cessna 140
- Occupation-Interests: Retired - Current 120-140 Assoc. NC Rep.
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Re: Which Propeller?
Click "Store" (above), then "Cessna 120-140 Marketplace" -- "Reference..." + order. Mac8475 wrote: ↑Sat Apr 25, 2020 9:03 amWhere can I find a copy of this alleged reference manual?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.
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- Name: Dave Sprinkle
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Re: Which Propeller?
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.2066 wrote: ↑Sat Apr 25, 2020 9:29 amClick "Store" (above), then "Cessna 120-140 Marketplace" -- "Reference..." + order. Mac8475 wrote: ↑Sat Apr 25, 2020 9:03 amWhere can I find a copy of this alleged reference manual?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.
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