Prop Pitch

[Airnsail 2]

I currently have a 13 x 10 3 blade prop on my Catalina 270. A friend of mine has a 14 x 14 Martec 2 blade foling prop. I checked with Martec. They reccomend a 14 x 12 prop for my boat.

What difference will I see and will this prop work on what I have now? Or can I have it re-pitched.

 

[Ross]

It depends on your reduction gear ratio but you would probably see some difference. You can usually gain or loose as much as 2 inches in pitch change. I have a 13x13 now repitched from 13x15 I get a little more engine speed but no more boat speed. The big advantage from my point of view is at full throttle I am not over loading the engine.

 

[Steve Dion]

Usually the prop shops have program to calculate the appropriate prop for each vessel. I would ALWAYS suggest that you use their calcs. If you engine will not rev to the designed RPM range or over revs you can put excessive wear on the engine.

 

[sailingdog]

Generally going up in pitch will reduce the maximum RPMs the engine can reach. Increasing the diameter does the same thing. A 14 x 14 prop may be too much for your boat, since you're going up in both pitch and diameter, and rather significantly in pitch. However, you are going to a two-blade rather than a three-bladed prop, so the reduction in prop surface area might make up for the additional pitch increase. It is hard to say without more information,like the HP of the engine and the gearbox ratios.

I currently have a 13 x 10 3 blade prop on my Catalina 270. A friend of mine has a 14 x 14 Martec 2 blade foling prop. I checked with Martec. They reccomend a 14 x 12 prop for my boat.

What difference will I see and will this prop work on what I have now? Or can I have it re-pitched.