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Sea Wolf
Joined: 01 Nov 2003 Posts: 8650 City/Region: Redding
State or Province: CA
C-Dory Year: 1987
C-Dory Model: 22 Cruiser
Vessel Name: Sea Wolf
Photos: Sea Wolf
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Posted: Mon Oct 04, 2010 6:25 pm Post subject: |
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Kevin-
Yes, there's a rule about altitude and power.
You lose 3% of your horsepower per 1,000 feet of elevation after the first 1,000 feet.
So at 8,000 feet (8,000ft-1,000ft) X 3%/1,000 ft = 21%, and
21% x 90 hp = 18.9 hp, and
90-18.9 = 71.1 hp left (!)
I've also seen discussions where high humidity, low atmospheric pressure, and a hot day take a lot more hp away. See:
A Little Foggy About How Weather Affects Horsepower? Allow Us To Explain
If I had to make a SWAG* , I think I'd opt for about a 13 inch pitch by 13.5"-13.75" or so diameter prop as a starting place.
Maybe you could borrow one and give it a test run (?)
No wonder many of us want 90 hp or more on a 22 and would consider a 115 hp motor for high altitude, heavily loaded situations!
*SWAG (Acronym of the Day)
Joe. _________________ Sea Wolf, C-Brat #31
Lake Shasta, California
"Most of my money I spent on boats and women. The rest I squandered'. " -Annonymous |
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KFoote
Joined: 14 Sep 2014 Posts: 94 City/Region: East Bridgewater
State or Province: MA
C-Dory Year: 2006
C-Dory Model: 22 Cruiser
Vessel Name: Foote Loose
Photos: Foote's Rest
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Posted: Sun Sep 14, 2014 6:40 pm Post subject: Prop- 13.5 X 15 on Honda 90 |
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I have a Prop- 13.5 X 15 on my Honda 90, pushing a 22 ft cruiser. After reading through this thread.
After 62 years of not paying attention to more experience. I am going to follow the rule (for once) - "If it Aint Broke - Don't Fix-It"
_________________ Keith Foote
Foote Loose
2006 22" C-Dory Cruiser |
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