3 to a 4 blade?

[jims3000]

i have a merc 150hp with a 3blade aluminum prop 23p and found a good deal on a 4 blade ss 24 pitch prop my holeshot is perty good wwith the 23p prop would the 4 blade 24p be to much of a difference?

 

[MikDee]

Re: 3 to a 4 blade?

That all depends on if your motors reaching it's recommended WOT rpm with the 23" pitch prop? If it's not, then No, the 4 blade 24" pitch won't work, it will only make your motor work harder, (lug) till it blows!

First when adding a prop blade you need to drop back in pitch, then if you are going from aluminum to stainless steel, you need to drop back in pitch again, that equals 2 changes of pitch back, to get approx. the same rpm as the prop you have now.

 

[jims3000]

Re: 3 to a 4 blade?

thanks for the reply

 

[soler]

Re: 3 to a 4 blade?

That all depends on if your motors reaching it's recommended WOT rpm with the 23" pitch prop? If it's not, then No, the 4 blade 24" pitch won't work, it will only make your motor work harder, (lug) till it blows!

First when adding a prop blade you need to drop back in pitch, then if you are going from aluminum to stainless steel, you need to drop back in pitch again, that equals 2 changes of pitch back, to get approx. the same rpm as the prop you have now.

What will going from 3 to 4 blades do, providing you go back in pitch like you said?

 

[MikDee]

Re: 3 to a 4 blade?

4blds, over 3blds, will give you more, & faster, torque (power & acceleration) on start up (hole shot), And throughout the whole rpm range, But because it has more surface area under water, the extra drag will scrub some top speed.
It may also give you extra bow lift, or stern lift, depending on the design.

 

[tmitchell5188]

Re: 3 to a 4 blade?

I just changed to 4 blades on my boat. I have twin 175's on my boat that had a 21" pitch, and I bought a pair of 19" 4 blades. My hole shot improved, but I lost some top end. But, I went from 12 GPH fuel consumpion down to 9 GPH at 5K RPM. But I went from about 30 MPH to about 27 MPH. If you can stand losing a MPH's, but you want better GPH & hole shot, this is the way to go. If you go up in pitch, I think you lose hole shot.