General propeller differences

[Matt S]

I'm looking to make an educated decision on a 2nd propeller to use on my 07 Glastron 185 with the 3.0L volvo package. We settled on the 3.0L versus the 4.6 because 80% of the time we'll just be out pleasure crusing and basking in the sun. We are perfectly happy with the stock propeller if we're just crusing around with some people on board but I'd like to find a prop I can put on if we have friends with us who want to ski or wakeboard for better hole shots. MAX speed is not a concern though I understand how a different pitch affects it. But I don't understand how the design of that pitch and materials the prop is made of affect it.

Can you help me understand just the basics between 3 and 4 blade, stainless, aluminum etc and their general effects? Or should I just pick the next lowest pitch and see how it performs? I don't really want a "buy this prop" answer, but more like "going stainless gets you this" and "a 4 blade will need a smaller diameter" and so on. I'd like to be a little more educated than just "buy the next size down 3 bade" which seems to be the answer at the shops. Then I could have this spare to use when we want to tow people. The stock prop is performing perfectly in relation to WOT with moderate load and all that. If we're not skiing the stock prop is fine. But I can tell once the motor is broken in and we have friends who want to be towed they'd be eating water longer than necessary.

Or is this just another vague question answered by numerous prop trial and error runs?

 

[sabastianunf]

Re: General propeller differences

4 blades will get you a better hole shot and more bow lift - rule of thumb is go down 1" of pitch to compensate for extra surface area of extra blade. You will need to know alot about your current prop as well such as if it is cupped. Cupped props will result in a better hole shot as well but will reduce the rpms you are running. Try to find a prop shop or marine mechanic that will let you test props before buying. read the other threads for info on stainless vs. alum.

 

[Matt S]

Re: General propeller differences

Ah, I did not know they would let me try it out before buying. I never enjoy spending hundreds of dollars on performace parts I have no knowledge of .
Thanks!

 

[Bondo]

Re: General propeller differences

Or is this just another vague question answered by numerous prop trial and error runs?

Ayuh,...........

It Could be Answered that way,.........
Or,......
you could just spend Several Hours reading the posts here at iboats...........

 

[sabastianunf]

Re: General propeller differences

Probably wont let you try new ones but lots of shops have used ones sitting around that will give you a good idea as to what design will give you the best performance.