Cupped Propellers?

[searayclassicglass]

Guys:<br />Has anyone out there used a cupped propeller? Did it give you more top end and cruising speed? I'm looking for top end speed, and I wanted to know if it worked before I send mine off to get cupped.

 

[LubeDude]

Re: Cupped Propellers?

The three things that come to mind that cupping a prop will do for you is:<br /><br />1. Wont ventilate as easily.<br /><br />2. wont blow out when you turn hard at WOT.<br /><br />3. will allow you to trim out farther.<br /><br />LubeDude

 

[Boatist]

Re: Cupped Propellers?

I do not think you are going to get any more speed just by cupping the prop. On a outboard it can give you a little more speed if after you put the cupped prop on you then raise the outboard. Raiseing the outboard means less drag and more speed. The cupped prop allows you to raise the outboard some without caviatation problems.<br /><br />If your are looking for more speed you really need a bigger motor. You might gain a little by getting a stainless steel prop with a pitch that will put you in the lower end of your WOT RPMS. If your engine WOT range is 4400 to 4800 get a stainless steel prop that the WOT RPMS is close to the 4400 end. This could give you as much as 3 MPH but that is it.<br /><br />Make sure your boat bottom is clean, Make sure the engine is tuned up, Lighten your load, Trim the bow as high as safe. Bottom line is only real speed increase will come from more HP.

 

[bob58]

Re: Cupped Propellers?

I changed to a cupped prop on my 26' and I got more top end (@150 to 200 rpm difference)and better hole shots.<br />speed at idle increased also.<br /><br />

Cupping<br /><br />Many of today's propellers incorporate a cup at the trailing edge of the propeller blade. This curved lip on the propeller allows it to get a better bite on the water. This results in reduced ventilation, slipping, and allows for a better hole shot in many cases. A cupped propeller also works very well where the motor can be trimmed so that the propeller is near the surface of the water. The cup will typically result in higher top end speed on one of these applications.

Quote Referenced from here