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Old 07-27-2014, 07:27 PM   #50
dimer2
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City: Cameron, La
Vessel Name: Baobab
Vessel Model: Bayliner 4788
Join Date: Aug 2013
Posts: 2,660
"Delfin when you flew you leveled off when reaching altitude thus greatly reducing power required. So you reduced pitch and rpm at the same time. That wouldn't be possible if you didn't change your angle of incidence. "

Once in straight and level flight, I would choose my cruise RPM and then increase pitch until I saw a drop of 100 rpm and then nudge it back a hair, giving maximum speed at a given rpm. This optimized pitch is obviously only for the given RPM and will prevent WOT.

I am having difficulty understanding why the same principal doesn't work for boats. If my cruising RPM is 1800 and I prop to achieve that RPM with the same throttle setting, disregarding WOT, I am not over loading the engine nor am I over propped....for that RPM. Purely IMO. Now how you would select the maximum pitch prop for that RPM, I have no idea.
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