Prop diameters?

[summit1]

I understand the relationship between pitch and performance. What about the diameter of the prop? If I want a prop that is going to give me a better hole shot (assume comparing 2- 19p props), would a 14.5" diameter prop or a 15.25" diameter work better? I would think the bigger diameter prop would work better on the low end, but create more resistance at top end than the smaller diameter prop. Is this correct?

 

[tommays]

Re: Prop diameters?

summit<br /><br />read here it tells all and will leave you scratching your head with the different types<br /><br /> http://www.mercurymarine.com/everything_you_need_to_know_about_propellers5 <br /><br /><br />tommays

 

[summit1]

Re: Prop diameters?

Thanks for the link. I am confused now. My theory is incorrect I guess. Here is what I am looking at doing: I have a Quicksilver Mirage 15"x19p SS right now. The performance is great right now when there are only 2-3 people in the boat (for skiing purposes here). When I have 5 people in the boat and I am trying to slalom...the boat drags me a while before I can fully get up. By the time I am up, I am tired from fighting the long pull. The boat came originally with a 21p prop, and it was down sized to 19p. I am happy with the overall performance, but wish I had a 17p prop to throw on for skiing when I know I am going to have 5 people in the boat while I am on the water. The prop I am looking at is a michigan wheel, 15.25x17p. If I am going with a spare prop for skiing, I want the diameter that will work best. Any other thoughts here? 18.5' Mariah 4.3merc Alpha 1

 

[sangerwaker]

Re: Prop diameters?

Have you tried a High Five yet? Best prop for holeshot IMO. They are also made by Mercury marine. See if you can try one from your local prop shop. Some places will let you and some won't. Doesn't hurt to ask.

 

[ddaigle]

Re: Prop diameters?

Generally as the pitch goes down the diameter goes up. This helps to offset some of the efficiency losses of lower pitch. The 17 will probably work fine or maybe even a 4 blade 15 if you really want takeoff. With the 15 pitch you would lose about 9-10 mph off top end, but for slalom skiing it would be nice.