Rat
Well-known member
Ran the boat today to get a good set of numbers. I made 6 two mile runs (one into the wind one with the wind); each lap's speed was averaged from my GPS log (using the water speedometer instead of the GPS speedo). Here are the results:
Motor specs: 1984 Evinrude, 150 HP, V6, 15 Spline shaft
RPM Range: 4500 - 5500
Propeller specs: 3 blade, 14.5" diameter, 22 pitch, stainless
Weather Conditions: 90 degrees, sunny, wind SSE 10-15 with gusts to 20
Lake Conditions: Three boats on the whole lake, slight chop (<6 inches)
Run One average: 63.7 MPH @ 4900 RPM
Run Two average: 66.8 MPH @ 4900 RPM
Run Three average: 63.8 MPH @ 4900 RPM
Total average: 64.76 MPH @ 4900 RPM
I can stand to go a little higher in my RPM range so...
In looking at the Solas charts I could use the 14 x 21 x 4 prop (aluminum) and be about right?
Solas has a 14 x 22 x 4 in stainless but I think this would keep my RPMs where they are now or maybe even lower them some. Plus, I'm just not ready to plunk down almost $400 for a new stainless prop right now.
will the 14 x 21 x 4 prop keep me in the RPM range I'm in now or do you think it would bring my RPMs up a little? I'm okay with the RPMs staying where they are but I would really like to bump them up a few hundred; but I don't want them to drop below what they are now.
So propeller gurus, is the 14 x 21 x 4 prop a good place for me to start?
FWIW, I usually cruise around 3900-4000 RPM which is real close to 40 MPH.
Motor specs: 1984 Evinrude, 150 HP, V6, 15 Spline shaft
RPM Range: 4500 - 5500
Propeller specs: 3 blade, 14.5" diameter, 22 pitch, stainless
Weather Conditions: 90 degrees, sunny, wind SSE 10-15 with gusts to 20
Lake Conditions: Three boats on the whole lake, slight chop (<6 inches)
Run One average: 63.7 MPH @ 4900 RPM
Run Two average: 66.8 MPH @ 4900 RPM
Run Three average: 63.8 MPH @ 4900 RPM
Total average: 64.76 MPH @ 4900 RPM
I can stand to go a little higher in my RPM range so...
In looking at the Solas charts I could use the 14 x 21 x 4 prop (aluminum) and be about right?
Solas has a 14 x 22 x 4 in stainless but I think this would keep my RPMs where they are now or maybe even lower them some. Plus, I'm just not ready to plunk down almost $400 for a new stainless prop right now.
will the 14 x 21 x 4 prop keep me in the RPM range I'm in now or do you think it would bring my RPMs up a little? I'm okay with the RPMs staying where they are but I would really like to bump them up a few hundred; but I don't want them to drop below what they are now.
So propeller gurus, is the 14 x 21 x 4 prop a good place for me to start?
FWIW, I usually cruise around 3900-4000 RPM which is real close to 40 MPH.