4 blade props on a B31

[jspiezio]

My dad is putting 4 blade props on his 31 at Elite. I keep hearing that they cruise more efficiently. Is this so? If it is so, would it pay to swap 3 blades out of a 32 Blackfin and add 4 blades?

I know this is rather vague info, and something that has probably been discussed before. I am hoping to get a general understanding of peoples experience with 4 blade props. I have never had or run a boat with them.

[Carl]

Aside from what I know about them I can tell you my dad picked up 2 knots at cruise on his Hatteras and enjoyed better low speed handling going from 3 to 4 blade wheels. Only down side was he lost some speed at top end and found the nose dug in more, but since he really does not run at that speed it was a none issue. Fuel burn was the same at the faster cruise.

On my boat I changed over to 4 blade wheels, but I also changed out the trannies from 1:1 to 1.52:1 so I can't really pinpoint the exact reason I got better performance. I can say from one brand of 4 blade wheels to another I picked up 3mph with same burn and even increased the top end. Same diameter and pitch with less cup.

[Capt. DQ]

You might want to take a look @ the Michigan DJX set of wheels. They give you the smoothness of a 4-blade but the speed of a 3-blade wheel.

DQ

[mike ohlstein]

My experience has been that the threes give a higher top speed and are cheaper to purchase. The fours are smoother running, get a better bite coming out of the hole, and throw a better 6.5 knot wake pattern for trolling. I also feel that they work a little better in reverse, because you can trade some cup for the increased surface area.

[jspiezio]

Thanks, these are helpful. I like the idea of a cleaner wake at troll. And in all honesty we very very rarely run at WOT, so cruise is really what I would be concerned with.

I am going to look at the DJX wheels, I have never heard of them before.

[dougl33]

I was talking with one of the guys from Acutech last week about 4 blades. He said for my boat I would be better off going with a 4 blade from ZF rather than the Michigan DQX. He said the ZF's (he didn't mention the model) had more blade area than the DQX's. He "thinks" I'd see better cruising numbers with 4 blades vs 3, but @ $1450 per prop I'm looking for more of a guarantee for my $2900.

[Dug]

I have 4 blades on my 31.

I think they are smoother.

They are more efficient at cruise. I know I lose top end, but I never run there, and it ain't a race boat, so I don't care about that.

I burn less fuel at cruise. That is what matters. And I have a good amount more torque delivery to the water both in docking as well as climbing back up waves.

I prefer the 4 blades for my application.

If I were driving a race boat, then 3 blade it would be!

Dug

[dougl33]

Dug,

What brand 4 blade are you running?

[Dug]

I believe they are Michigan Wheel dynaquads...

But it has been 4 some odd years since I have looked!