Bertram31.com General Bulletin Board

Re: prop questions

Posted By: Paul J
Date: Tuesday, 16 August 2005, at 5:38 p.m.

In Response To: prop questions (thudddd)

I was reading about your delima on prop size (diameter/pitch) and wanted to understand a bit more myself. What I read leads me to believe your prop diameter and pitch are both too large.

The rule of thumb for our boats should be to keep the diameter/pitch ratio close to 1:1. Another rule of thumb is that every 1" in pitch reduces RPMs by ~200.

Given this, if you are 200-400 RPMs shy of max RPM at WOT, you should reduce pitch by ~2". Keeping the ratio close to 1:1, wheel size should be reduced as well.

Hope this helps.

Messages In This Thread

prop questions
thudddd -- Monday, 15 August 2005, at 4:17 p.m.

Re: prop questions
Walter Kaprielian -- Monday, 15 August 2005, at 5:20 p.m.

Help Mike!
Bruce -- Monday, 15 August 2005, at 6:21 p.m.

Re: Help Mike!
mike ohlstein -- Monday, 15 August 2005, at 7:10 p.m.

Re: Help Mike!
Capt. Dick Dean -- Monday, 15 August 2005, at 8:45 p.m.

Re: Help Mike!
thudddd -- Tuesday, 16 August 2005, at 8:42 a.m.

Re: Help Mike!
andre fourrier-Louisiana -- Tuesday, 16 August 2005, at 9:22 a.m.

Re: Help Mike!
thuddd -- Tuesday, 16 August 2005, at 9:56 a.m.

Re: Help Mike!
capy -- Tuesday, 16 August 2005, at 8:51 p.m.

Re: prop questions
Gary Gibson -- Tuesday, 16 August 2005, at 4:21 p.m.

Re: prop questions
Paul J -- Tuesday, 16 August 2005, at 5:38 p.m.

Re: prop questions
thuddd -- Wednesday, 17 August 2005, at 8:57 a.m.

Re: prop questions
Paul J -- Wednesday, 17 August 2005, at 9:47 a.m.

Re: prop questions
capy -- Wednesday, 17 August 2005, at 11:47 a.m.

Re: prop questions
thuddd -- Wednesday, 17 August 2005, at 4:16 p.m.

Re: prop questions
Gary Gibson -- Wednesday, 17 August 2005, at 5:49 p.m.

Re: prop questions
thuddd -- Thursday, 18 August 2005, at 9:54 a.m.

Re: prop questions
Carl -- Thursday, 18 August 2005, at 12:30 p.m.