Questions on why a prop gets so much grip, and suggestions on a 4 blade.

mwe-maxxowner

Master Chief Petty Officer
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Jun 20, 2012
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I own a 1986 Dixie hustler 188. 18'8", with a somewhat shallow v open bow. Powered by a 2 barrel 4.3.

When I bought the boat it had a 21 pitch prop, and seemed sluggish. It struggled to reach 3800 rpms and 40 mph with only two guys on board.

I have since rebuilt the boat, and put on a borrowed solas 19 pitch prop. I don't know whether to attribute the performance gains to losing water weight, or the prop, but now I can reach an easy 4500 rpms and 45 mph with five people on board and a cooler full of drinks. With the two guy load it normally sees I can easily get up to and maybe even past 5000 rpms.

I feel I'm pitched just about right, I think this motor should have the muscle to run a larger prop, but it seems nice and strong with this 19, pulling up boarders with 5 people on board.

I'm ready to start searching for my own prop. There are a few things I find interesting. With this Sola's prop, I can turn hard at any speed, even while trimmed up, and it almost never loses its bite and blows out. At slow speed I can trim up and up and up and it will stand the boat straight up, never loses its grip!

What characteristics of a prop give this type of performance?

I want to go with a 4 blade, as this boat is mostly for watersports. I read they hold speed a little better and wander a little less? In water that is a little choppy with 5 people on board it wanted to porpoise a little at cruising speed of maybe 35 mph if I trimmed up much at all. For all I know that may just be normal.

Any recommendations on a 4 blade prop for my situation?

And also just curious as to answers on why my current Solas prop seems to get much more "grip" than another 3 blade prop.
 

steelespike

Supreme Mariner
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Apr 26, 2002
Messages
19,069
Re: Questions on why a prop gets so much grip, and suggestions on a 4 blade.

I'm pretty sure your 2 barrel 4.3 is rated at 4800 rpm.I would avoid 5000 if possible.
You must have made some serious changes in the hull if you a have
improved that much without doctoring the motor. A 21" prop should put you over 50 lightly loaded.
The Solas props heave a good reputation for good predictable performance.
They have state of the art "Squeeze cast" technology. Makes thinner,stronger blades it probably is a cupped prop.
Seeing as you over rev with a light load I think a 4 blade 19" Solas prop should should put you closer to the right rpm.
I do wonder if you rebuilt the transom perhaps the outdrive is slightly lower than normal.
 

mwe-maxxowner

Master Chief Petty Officer
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Jun 20, 2012
Messages
825
Re: Questions on why a prop gets so much grip, and suggestions on a 4 blade.

I doubt it. The outer skin stayed completely intact so the keyhole should be in the same spot.

Also, I said I could reach 5000 rpm, not that I do! Figured that out while trying it out the first run back in the water, but keep it at 4500 rpms since.

Really haven't done anything to the motor. A good carb cleaning is in order because it doesn't idle the greatest.

I was also thinking about a 19pitch 4 blade solas since the extra blade will bring rpms down a bit. Should I expect it to slow me down much from my current 45 miles per hour?
 

Fleetwin

Lieutenant Junior Grade
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Nov 23, 2011
Messages
1,141
Re: Questions on why a prop gets so much grip, and suggestions on a 4 blade.

Trust Steelspike's advice. Few, if anyone, knows more about props than him.

Was your indicated speed by speedometer or GPS? Boat speedo's are notoriously inaccurate.

If you are primarily looking at watersports, underpropping is not a completely bad plan. As the operator, you need to make sure you don't overspeed the engine.
 

mwe-maxxowner

Master Chief Petty Officer
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Jun 20, 2012
Messages
825
Re: Questions on why a prop gets so much grip, and suggestions on a 4 blade.

Yes I understand this, and I have been careful to watch the tach. The speed is by GPS, I haven't even installed the speedo back on the boat yet.

I've thought about keeping the 21 for cruising, but the change in activity from playing to going for a nice night ride usually happens while the boat is still in the water.

The props I had been thinking about were a 17, 18, or 19 solas 4 blade. I was considering the 17 after my experience with the 21 before rebuilding the boat.

I think a solas 19" prop will be in order by the beginning of next season. Do they have different 'styles' of prop or is there only one solas 4 blade in aluminum for me to select from?

I have realized in general that watersports with a smaller prop uses less fuel, but while out cruising and sight seeing a larger prop does better on fuel.

Thank you both for the advice!
 
Last edited:

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Questions on why a prop gets so much grip, and suggestions on a 4 blade.

Typically you lose some speed but thats usually with a pitch reduction. Your staying with a 19 theoretically assuming the 4 blade can make 4500 rpm speed would be about the same.
 
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