Changing to a 4 blade prop.

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New Member
Mar 3, 2007
12
Long Island
Boat Info
1996 215EC
Engines
5.7L, Alpha 1 Gen2
I was thinking of replacing my 3 blade prop with a 4 blade prop., and was wondering if anyone has any experiences, good or bad, using a 4 blade. Short of converting to a Bravo 3, I am wondering if a 4 blade prop would offer more control when backing down into a slip. The boat gets up on plane ok, and I'm not really concerned with top end, as I usually just cruise when on plane, so control would be the only reason to try a 4 blade; that and the fact that I would be replacing the prop either way in the spring. The boat is a 2000 24 Sundancer with a Bravo 2 drive.
 
From what I've been told. You should gain a few knots at idle, more fuel efficiency at cruise and smoother ride. I just switched from 3 to 4 but haven't launched the boat yet.
 
A 4-blade prop will not provide much, if any, noticeable improvement when backing down with a single engine. When backing with a single engine and non dual prop the stern boat is going to move to one side or the other depending on prop rotation direction....period. There is not a lot you can do. Its a matter of physics.

Sounds like its time for a twin engine boat.
 
I did this on an outboard some years ago-150hp Johnson GT...The only noticeable difference was faster on plane and less top end speed.

Bennett
 
I had a 24ft cruiser with a B2 and went to a Mercruiser 3 blade stainless prop and noticed a good difference in performance including time to plane and top end. I think the heavy boat with aluminum prop gives too much blade flex. As others have said, the dock handling with a single prop I/O is not great no matter what prop. You just need to learn how bad it is and how it reacts and live with it.
 
I would invest in a stainless steel prop before going to a 4 blade. You will notice the difference.
 
I had a 24" cruiser with an Alpha1. Went from 3 blade aluminum to 4 blade aluminum - same pitch. Made a noticable difference in low speed planing, and holeshot. I tried a 3 blade SS prop first, and it did not improve low speed planing, just top end increase.

None of the changes compensated for the leg walking sideways backing up.
 
paulswagelock said:
I had a 24" cruiser with an Alpha1. Went from 3 blade aluminum to 4 blade aluminum - same pitch. Made a noticable difference in low speed planing, and holeshot. I tried a 3 blade SS prop first, and it did not improve low speed planing, just top end increase.

None of the changes compensated for the leg walking sideways backing up.
Click to expand...

I also did the same on my first boat with a 4.3L Alpha. I put on a 4 blade aluminum. It was smoother feeling and faster to pop on plane, but I lost a few MPH at the top end. Once again, no difference in dock handling from that change. It did help with tubing in terms of getting up faster and being able to hold plane at lower speeds, so it was a good change from that perspective since that was what I was looking for.
 
if your interested I have a "Big Cow" 4 blade SS prop for that Bravo 2 for sale
I paid 750.00 for it and end up selling the boat before I got a chance to put it on
will let it go for 500.00 shipped to you if you like
let me know
Thanks
Scott 203-887-5787
savo1@optonline.net
 
Had a 2000 245 weekender,B2, 4 blade SS prop was the best thing I did to it. Backing into the slip was a huge difference. Got a nice stern lift on accell ,and lower cruising rpm's. Well worth the money I paid for it. Big big difference over the aluminum 3 blade

Less deflection with stainless, yes you will notice it
 
I went from 3blade Al to a 4 blade composite. Night and day difference in forward. Still a beyotch to back into a slip. It still walked.
 
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