3 Blade Propeller

[nauticalrich]

I have a 1985 Oday 31 with 14 hp diesel, 2 blade prop.

Looking to increase speed under power. Is it a big deal to change from 2 to 3 blade and anyone have experience with results.

Also there was a super duper performing 3 blade prop I saw several years ago. Can 't remember the name. Any recommendations.

PS, only want fixed prop, no folding.

Thanks

 

[Maine Sail]

I have a 1985 Oday 31 with 14 hp diesel, 2 blade prop.

Looking to increase speed under power. Is it a big deal to change from 2 to 3 blade and anyone have experience with results.

Also there was a super duper performing 3 blade prop I saw several years ago. Can 't remember the name. Any recommendations.

PS, only want fixed prop, no folding.

Thanks

Campbell Sailer Prop West By North (LINK)

 

[RAD]

I switched to a Campbell sailor prop a couple of years ago and loved the performance,unfortunately I found out after replacing my tachometer that I could not get the engine over 1500 rpm and that was because its over pitched.
I ended up putting the original 2 blade back on but just yesterday I removed it so I can bring both to the prop shop and have the 3 blade re pitched using the information of pitch and diameter of the 2 blade
I don't know what the pitch is for the 2 blade but the Campbell prop is 12 x 5 and I'm pushing a 32 with a 30hp Westerbeke.
BTW
It was a pleasure to do business with Norman at Campbell because he got me the product quickly and at a great price during a short haul a few years back.

 

[maestro]

I have a 1985 Oday 31 with 14 hp diesel, 2 blade prop.

Looking to increase speed under power. Is it a big deal to change from 2 to 3 blade and anyone have experience with results.

Also there was a super duper performing 3 blade prop I saw several years ago. Can 't remember the name. Any recommendations.

PS, only want fixed prop, no folding.

Thanks

Rich.......YOU OWN A SAILBOAT!!!! switching from 2 to 3 blade is not going to increase your boat speed by very much. You can only do hull speed You'll get more torque and more manuverability (and more prop walk) but the negatives far outweigh the positives (IMHO). Under sail a 3 blader is like dragging a bucket behind your boat. You really should reconsider a folding (or 3 blade feathering prop)

 

[Maine Sail]

Rich.......YOU OWN A SAILBOAT!!!! switching from 2 to 3 blade is not going to increase your boat speed by very much. You can only do hull speed You'll get more torque and more manuverability (and more prop walk) but the negatives far outweigh the positives (IMHO). Under sail a 3 blader is like dragging a bucket behind your boat. You really should reconsider a folding (or 3 blade feathering prop)

Actually one benefit of the Campbell 3 blade is that is has comparable drag to the "standard" Michigan MP or Michigan Sailer two blade prop most production boats came with.

If you live in an area with any current, or an area with "light & variable winds" (meaning sometimes none), there is no doubt that a good three blade prop is worth the money.

A Michigan Sailer 3 blade is about 30 lbs of drag at 5 knots

A Campbell Sailer 3 blade is about 17 lbs of drag at 5 knots

A Michigan Sailer 2 Blade is about 16 lbs of drag at 5 knots

A Martec 2 blade folder is about 14 lbs of drag at 5 knots

(reference MIT Prop Study 1994)


There is also no questions that mechanical props require much more maintenance and are significantly more expensive. Despite having fixed three blade props on all three of my last boats I had no problems sailing at hull speeds and quite often dusting boats with much lower PHRF ratings. Sometimes knowledge of sail trim and how to sail your own boat effectively means more than the prop you're dragging..

 

[Irishbarr25]

I have a Oday 25 with a Zepher 25hp 3 blade they say the motor is a mate to evenrude / johnson Can you get a folding prop for it? $ / where?

 

[nauticalrich]

I have trouble even reaching hull speed with the 2 blade prop. I am hoping the 3 blade will help it out.
I went ahead and ordered it. The spces came back 13 inch diameter, 7 inch pitch, for a 1 inch shaft.

They say they use the Michigan specs for pitch and the drop it down.
Oh well, what the hell, spring is coming.

 

[RAD]

Did you order it from Campbell? I had a 12 X 5 with a 25 hp pushing a 32 ft and that was too much pitch or diameter cause I could get to hull speed but the engine wouldn't reach past 1500 rpm and thats not good for an engine thats rated for 2500.
So it seems to me that the prop you ordered will be too much, also do you have the correct prop on the boat now? and does your engine reach its rated top rpm with the 2 blade prop?

 

[Larry14133]

Folding prop

I have trouble even reaching hull speed with the 2 blade prop. I am hoping the 3 blade will help it out.
I went ahead and ordered it. The spces came back 13 inch diameter, 7 inch pitch, for a 1 inch shaft.

They say they use the Michigan specs for pitch and the drop it down.
Oh well, what the hell, spring is coming.

I know you said no folding prop but I did go from a two bladed fixed to a three bladed Flex O fold. I can not speak to the maintenance, I do all my sailing in fresh water and don't have and problems with the prop fouling. The boat handles great in Fwd and Rev and stop to hull speed and hull speed to stop is much faster and the boat is faster under sail. I would not go back to the fixed prop.