Reducing pitch for a 4 blade prop

[AUGIDAWG]

I was looking at this web site, and noticed they recommend reducing the pitch on some of their 4 blade props, sometimes 1-2", or 3-4" for highly cupped props.<br /><br /> http://www.a1discountprop.com/pow-john-evin.htm <br /><br />I called them, and they said they recommend whenever going from a 3 blade to a 4 blade, reduce the pitch by 1" as a general rule. This is because of more area of the prop in the water.<br />Sometimes more than 1".<br /><br />I'm still trying to decide between the 4 blade Turbo 2+2 18" pitch, or the Renegade 17" pitch.<br />I now have the stock aluminum 3 blade 19"pitch on my 95' 200 Ocean runner, running about 5800 rpm.<br />I want less pitch for rough ocean going, so I want to be able to hit 6000 rpm at least.<br /><br />What do you think?

 

[Dhadley]

Re: Reducing pitch for a 4 blade prop

The 3 blade and 4 blade props will run at different X dimensions. If you are not going to dial in the 4 blade thats probably why they recommend losing an inch or so. <br /><br />The 2+2 is a great prop but we've had more success with the Turbo Ultima 4. Still 14 1/4 diameter but different blade shapes. <br /><br />Good luck!

 

[AUGIDAWG]

Re: Reducing pitch for a 4 blade prop

The 2+2 is a thru hub exhaust. I'm not sure about the Ultima 4.<br />A guy at "Propellers Online", just told me that he recommends the Ultima 4, 17" pitch for my application in rough water. The Ultima 4 has bigger and different shaped blades than the smaller bladed "2+2 TH", and from their experiences, is a better offshore prop.<br />I asked him about what would happen to my 5800 rpm. He said it would be about the same as the stock 19" aluminum, because I would have another blade in the water, and it would stay hooked up in rough water a lot better, and produce much better pull and bow lift.<br />I asked how the 18" 2+2 would effect the rpm.<br />He said it would be the same, and that the 2 props have the same equivelent pitch even though they are 1 inch different in measured pitch.<br /><br />Ok, so now that is 2 experts recommending the Turbo Ultima 4.<br />Anyone else have good feedback on the Renegade 17"?<br /><br />Thanks. Time to pull out the credit card.

 

[JB]

Re: Reducing pitch for a 4 blade prop

Moving to General Outboard