Thread: Under propped?
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Old 03-27-2014, 10:27 AM   #39
Nomad Willy
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City: Concrete Washington State
Country: USA
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 16,228
FF says;
"To change the LOAD the usual method is to select a load , gen head , water pump size or Propeller that fits the desired load at the desired RPM.."

Fred there's no such thing as "desired rpm". Unless you have a variable pitch prop the load is fixed. The rpm to load to is exact. The rpm where your engine develops it's maximum power. 3000rpm in my case and I need to prop to that engine speed as closely as possible. Preferably any variation should be in the underpropped direction as in 3050rpm being preferable to 2950rpm.

Your cruise prop notions are like trying to drive a diesel truck around in high gear. Not for normal people and normal boats.
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Eric

North Western Washington State USA
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