3 blades or 4

[popazog]

Can someone please clarify for me what I could expect from a 4 blade prop? I understand the basics of propping... 1 inch increase in pitch will decrease RPM 150-200 and 1 inch decrease in pitch will do the opposite by adding RPM. What I want to know is would a 4 blade of the same pitch as my 3 blade Mirage plus affect my RPM up or down. I want to gain a bit more RPM (I am at the low end of Mercury's recommended WOT) but I don't want to lose any of "Hole Shot" power I get from my 17" Mirage Plus. Would a 17" Revolution 4 do the trick?

 

[DJ]

Re: 3 blades or 4

papzog.<br /><br />The four blade will have a better bite and will, in many instances, improve holeshot.<br /><br />The also tend to hold better, allowing more positive trim and will hold better while turning.

 

[popazog]

Re: 3 blades or 4

Thanks djohns19, I thought a 4 blade would provide better performance and handling, but do you think it would bring my RPM up a tad... I read somewhere that 50-100 more RPM could be expected when switching to a 4 blade. Is that accurate?

 

[beckerdg]

Re: 3 blades or 4

A four blade prop will generally give better hole shot and hold better, but give slightly lower rpm and top end. From what I have read when I bought a new prop, this is due to additional resistance/friction of pushing another blade through the water. Again not from personal experience.

 

[DJ]

Re: 3 blades or 4

A four blade will remain the same RPM or decrease slightly, depending on design.<br /><br />Four blades will RARELY gain rpm over a three.

 

[Alan Moriarty]

Re: 3 blades or 4

I went from a 19 pitch 3 blade to an 18 pitch 4 blade. RPM was up from 4200 to 4450 but speed dropped from 35 mph to 33 mph. The trade off was a bit more torque and a LOT tighter turning. I like it !