Propeller - 3 or 4 Blades

[Hydrosport24]

Will a 4 blade prop give me better steering control at slow speeds (docking the boat)? The boat is docked in a slip on a river that produces strong currents at times.<br /><br />I also do a lot of Trolling would the four blade make the boat move slower of faster,<br />Hydrosport24

 

[Kiekhaeferscurse]

Re: Propeller - 3 or 4 Blades

Only tried a 4 bladed prop once myself (merc) the proplem I had with it was so much rake it wouldnt pull the boat in reverse.<br />I'm not to sure if its the blade numbers you should be concerned with, more the rake & pitch.

 

[Laddies]

Re: Propeller - 3 or 4 Blades

a standard design 4 blade will ussually produce more power on acceleration, but any prop with alot of rake won't back up well. if your 3 blade is not blowing out probaly a 4 blade wouldn't help much

 

[Nafta_84]

Re: Propeller - 3 or 4 Blades

Also with the four blades, there is more drag coming from the extra blade, but thats all i no the motor i use is only 2 bladed

 

[charlie_kula]

Re: Propeller - 3 or 4 Blades

Evinrude propeller basics:<br /><br /> http://parts.evinrude.com/info/parts/propellers_files/prop8.htm

 

[nordy]

Re: Propeller - 3 or 4 Blades

The more blades => the less efficiency (80% best for a two blade).<br />The one blade has the least turbulences.<br /><br />You must choose a model with less pitch, when choosing a higher blade type, because otherwise engine load would be too high => sinking engine speed and power.<br /><br />In any case four blades mean more slippage due to higher turbulences => higher engine speed.<br /><br />Higher engine speed with respect to boat speed generally means higher engine power.<br /><br />So acceleration may be better though efficiency is deteriorated (at the expense of higher fuel consumption).<br /><br />Nordy

 

[Dhadley]

Re: Propeller - 3 or 4 Blades

A 4 blade prop should let you run a higher X dimension. You must remember to compare 3 and 4 blade props of the same or similar design (technology). <br /><br />Running a 4 blade prop at a higher X dimension than the same/similar design 3 blade will reduce drag and increase overall efficiency from idle to wot.