Used prop purchase

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
Re: Used prop purchase

With the same brand and style propeller, a 2 inch pitch drop will generally run about 400 RPM faster. Stainless will run about 200 RPM faster than aluminum. So, in the worst case, you will gain 600 RPM.

However: I can not compare the Laser to your current prop but it is a reasonable assumption that the stainless will turn more than 4400 on your boat
 

captmello

Captain
Joined
Jun 30, 2008
Messages
3,845
Re: Used prop purchase

With the same brand and style propeller, a 2 inch pitch drop will generally run about 400 RPM faster. Stainless will run about 200 RPM faster than aluminum. So, in the worst case, you will gain 600 RPM.

However: I can not compare the Laser to your current prop but it is a reasonable assumption that the stainless will turn more than 4400 on your boat

Thanks for the reply. I was familiar with the 400 RPM difference from the 19 to 21, but not the 200 additional because of the SS. I thought it would be the opposite since the stainless was stiffer.

I guess I better stick to the 21p.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Used prop purchase

Just because the prop has the diameter and pitch you need does not mean its made for your outdrive so make sure of that. As for stainless vs aluminum regarding RPM gain or loss that's a very big IF! How much difference there is depends on the quality of the aluminum vs the quality of the stainless. And then the opposite is also possible. If you compare a high quality stainless to a run of the mill aluminum the difference can be significant. Prop selection is a crap shoot when you start changing more than one parameter at a time.
 
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