3 or 4 blade and what pitch

[leprican22]

I have a 2005 Tahoe 234 Deck boat. I believe it weighs right at 3000 lbs. It has a 5.7L with Alpha 1 outdrive. The prop that is on it now is factory and is has a pitch of 19. (not sure on the diameter) I have planing problems at lower speeds when the boat is loaded down (about 7-8 people) Because my lake is pretty rough, keeping a plane at lower speeds is a must. What type of prop would be best for this. Keeping the 3 blade and going to a pitch of 21 or getting a 4 blade and keep the same pitch i have now. I am not looking for top end speed because to be honest, I never ride at wide open throttle anyway. Any help would be greatly appreciated!!

 

[steelespike]

Re: 3 or 4 blade and what pitch

Welcome,read the stickies at the top of the page and the helps at the top of iboats prop store page.This will help you understand prop selection better.
What is your present max rpm and speed?(light and loaded)And the rated max of the motor?usually on a label on the motor.With this info we can help select a prop.
A four blade will help your low end performance. Trim tabs will greatly improve your planing and stay on plane at lower speeds.Smart tabs are passive tabs and reasonable and easy to install.

 

[Tail_Gunner]

Re: 3 or 4 blade and what pitch

Welcome,read the stickies at the top of the page and the helps at the top of iboats prop store page.This will help you understand prop selection better.
What is your present max rpm and speed?(light and loaded)And the rated max of the motor?usually on a label on the motor.With this info we can help select a prop.
A four blade will help your low end performance. Trim tabs will greatly improve your planing and stay on plane at lower speeds.Smart tabs are passive tabs and reasonable and easy to install.

Agreed Tabs will do a lot, If you could post your boats current performance at Wide Open Throttle such as speed and rpm. That will allow a prop choice that Does Not lug your motor at low to midrange speeds...if you still want a prop. You might also give a indication as so ss or alum.

 

[JJJ]

Re: 3 or 4 blade and what pitch

Going up in pitch will most likely make the situation worse, but it is just a guess without the needed info.

I think you want a prop that will give you good lift and get the hull out of the water - due to the rough conditions - correct?

 

[Silvertip]

Re: 3 or 4 blade and what pitch

There is a simple way to determine the diameter of a prop. A ruler works well for this. For three blade props measure from the tip of one blade to very center of the prop shaft and multiply that number by 2. For four blades measure from blade tip to opposite blade tip. If you think performance is bad with a 19P it will be very much worse with a 21. Going up in pitch removes RPM. Going down in pitch raises rpm. Your engine is already struggling so a decrease in pitch is required. But as the "sticky" indicates, we can't tell you what you need until you give some baseline numbers to work with.

 

[leprican22]

Re: 3 or 4 blade and what pitch

Thanks for the replies. I am glad I asked before I went out and bought something! My assumptions were all wrong! I wont get a chance to test until maybe this weekend but I will post as soon as I do.