[PUP] :PPM-propeller efficiency

[Kevin Kearney]

I recently repowered with a non-turbo Deere 80HP-the torque peak is at 1200-1400rpm-twisting a 34 inch prop at 500rpm-Overpropped since the engine "stalls" at 1750rpm-out of a 2400rpm redline-but operating at 1200-1400rpm fuel economy is sub 1gph my sl is 1.125 at 7.5 knots and the torque the twisting action of the engine is at is max 220ft pounds demiinishing to 170ish ft pounds over 2000rpm as the fuel consumption goes over 4gph. 

Deere would not warrenty an engine so overpropped- but it works well/better when you match cruising speed to the torque peak of the engine'

Kevin Kearney/Jolie/Baltimore

--- On Sun, 11/23/08, Patrick Gerety <alohaboat at yahoo.com> wrote:
From: Patrick Gerety <alohaboat at yahoo.com>
Subject: Re: [PUP] :PPM-propeller efficiency
To: "Passagemaking Under Power List" <passagemaking-under-power at lists.samurai.com>
Date: Sunday, November 23, 2008, 1:35 PM

>but does that give us maximum efficiency (fuel  
>
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