3 blade vs 4 blade

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crazyhunter

Petty Officer 2nd Class
Joined
Jan 25, 2012
Messages
128
i have a blackmax 150 and want to put another prob (21p) should i get a 4blade or 3blade? whats the pros and cons of each? i want more topend.
 
Texasmark

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,560
Re: 3 blade vs 4 blade

I don't have, nor ever owned a 4 blade. In reading replies on here for several years, it seems that a 4 blade does better at the mid-range speeds where one would cruise. It allows for better speed control than some 3 blades....boat doesn't try to run away on plane and once you cut the throttle to control that speed, it falls off plane, transom sinks and you have to repeat the process.

Other thing is that for a heavy transom boat, like a bass boat, and I/O if you have the HP to push it, it gives you a better "hole shot" (plane out...getting on top of the water from being in it).

HTH,
Mark
 
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dan02gt

Chief Petty Officer
Joined
Aug 30, 2012
Messages
463
Re: 3 blade vs 4 blade

crazyhunter said:
i have a blackmax 150 and want to put another prob (21p) should i get a 4blade or 3blade? whats the pros and cons of each? i want more topend.
Click to expand...

What kind of boat is this going on?
 
phillnjack2

phillnjack2

Ensign
Joined
Apr 30, 2011
Messages
918
Re: 3 blade vs 4 blade

4 blade gives better bottom end ,but slower top end.
I asked this same question to some professional prop guys, all said the same thing.
They also said the 4 blade is a better cruise prop but no good for top end.
Now also this is when comparing 3 and 4 blade of same make and type of blade ????
there is now so many different props out there to choose from.

I was comparing a 3 blade raker to a 4 blade rengade, both omc props.

but if its top end your after you will want to be looking for 3 blade or even a 2 blade if you can find one.
and how high are you running ? if up high you might want to think about surface or semi -surface to get more speed.?




phill
 
jestor68

jestor68

Commander
Joined
Jun 12, 2012
Messages
2,308
Re: 3 blade vs 4 blade

No one can say which would perform better until you describe your set up.

Read the sticky at the top of the section and provide as much info as possible.
 
spoilsofwar

spoilsofwar

Lieutenant Junior Grade
Joined
Jun 29, 2011
Messages
1,124
Re: 3 blade vs 4 blade

I am all about the 4 blade prop. Love the quickness to plane and the ability to stay on plane at lower speeds. I gave some up on the top end but my boat is pretty quick for its size and engine so its worth it to me.

That being said, like the others have posted, it all depends on the boat. If you were happy with your boat's performance with the 3 blade prop, there is probably no reason to switch. If you want better holeshot, and lower planing speed a 4 blade may be for you. I've also read that 4 blades provide better slow speed handling, like when docking, but I couldnt notice it. If you like going WOT and trying to get every mph out of it, then 3 blade for sure.
 
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crazyhunter

Petty Officer 2nd Class
Joined
Jan 25, 2012
Messages
128
Re: 3 blade vs 4 blade

thanks for the info i think i will stick with 3 blade ive got a 3blade ss (17p) it will run about 50 so im lookin for a little more topend
 
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crazyhunter

Petty Officer 2nd Class
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Jan 25, 2012
Messages
128
Re: 3 blade vs 4 blade

also will vented props alow me to keep my holeshot without loosing topend?
 
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Georgesalmon

Lieutenant Commander
Joined
Apr 14, 2012
Messages
1,793
Re: 3 blade vs 4 blade

Venting allows the prop to ventilate a little bit when starting out. So the engine can reach high rpm's more quickly, then the scavenging effect at speed pulls the exhaust out the hub and no more ventilating. I can't remember who but someone makes a prop that allows you to change the hole size easily, or close it, that might be a good choice to try.
 
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crazyhunter

Petty Officer 2nd Class
Joined
Jan 25, 2012
Messages
128
Re: 3 blade vs 4 blade

about 6k wide open i need to bring it down to around 5500
 
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Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,158
Re: 3 blade vs 4 blade

Sounds like a 19" pitch 3 blade prop is about right. I like the Hustler props in aluminum
 
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