4 Blade Vs 3 blade

Last Dollar

Last Dollar

Active Member
May 10, 2011
245
Huntington WV boating the Ohio River and lakes in
Boat Info
Sea Ray 225
Engines
5.0 Mercruiser
Just did a little test running and decided a 4 blade is much better for the type of running I do. My 03 225 Weekender with a 5.0 Alpha had a 3 blade stainless 19 pitch when I bought the boat, I assume this is the original prop. I tried a borrowed 4 blade aluminum 19 pitch and with using a GPS to determine speed on both props I got 3 mph faster at the same 3000 rpm with the 4 blade. I also had recorded the rpm at which I obtained 30 mph. With the 3 blade stainless I needed 3400 rpm but with the 4 blade aluminum I only needed 3150 rpm.

The boat planed off quicker and stayed on plane better at slower speeds.
 
I think most Alpha drive boats would benefit from this change. I did it to our boat 2 seasons ago and the difference is amazing.

You should see faster mid range acceleration as well.
 
I'll be doing this mod to my boat in the spring, I'm after quicker out of the hole and reduced planing speed. Dont think I' ever get my money back on fuel saved I just think it will suit my 'boating style' better.
 
I'll be interested in opinions from both of you after you do the switch. I go full throttle about once a season so a bit of top end loss won't bother me one bit. The cost of the 4-blade prop that I have been eyeing for the Bravo 2 is $650.
 
saopm said:
What brand props did you guys buy? I see some Solas 4 blades that run around $330 a prop. Not sure if that is good or bad.
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I've heard them called sloass but I don't have any personal experience with them. I have had very positive dealings with Powertech! Their products are well made and competitively priced. They are knowlegable and friendly to talk to.
 
Last year I switched from a 3 blade aluminum 14.25 x 21 to a stainless 14.125 X 19 260 V8 / Alpha 1 - 210 Seville MC

Aluminum 3 blade prop - 1,000 rpm (no wake speed) 3.3 mph 3,500 rpm - 25 mph and topped out 4,400 rpm 40 mph - Very slow out of the hole (I'm guessing 10+ seconds to get on plane)

Stainless 4 blade prop - 1,000 rpm (no wake speed) 4.6 mph 3,300 rpm - 25 mph and topped out 4,500 rpm 41 mph - Jumps out of the hole (I'm guessing 5 seconds to get on plane)

All speeds are per the GPS

All in all I am EXTREMELY happy with making this swap, It's like I have a new boat. - I see no down side in this case. I know this will not be the same result for everyone but I thought some would be interested in the information.

BTW - I used a Solas Rubex and have had no issues with it.

LK​
 
The prop I borrowed was a Solas 14.25x19 four blade aluminum. It's now on sale I believe at iboats for $98. My son bought this prop a couple of seasons ago when he was experimenting with props on his 215 Express Cruiser. He was really impressed with it's performance and used it a couple of seasons until he hit a floating log and bent a blade. It was not too bad and could be straightened with a hammer but from then on he felt a little vibration and lost confidence in it. It became a great spare. Stainless would be better of course but shelling out $300 for a pitch and style you are not sure will work is a little risky.

I think the aluminum Solas props are a great prop for that kind of money. We don't run our boats flat out and rarely do we go above 3500 rpm. From what we have found by recording speed and rpm if you like to run wide open all the time then a four blade and especially an aluminum prop may not be a good choice. Of course I'm beginning to think the risk of bending a prop shaft with a strong stainless prop is not the best choice depending on the waters you boat on. We are Ohio River/lakes in Kentucky boaters for the most part and the possiblity of running over floating logs is always good. I would rather eat the expense of another aluminum prop than be faced with a bent prop shaft and tear down of the gear case to fix it. I would think a duo prop outdrive could end up costing you easily two thousand in parts alone if you bent the shafts.
 
I run a 4 blade Merc stainless on my 270. It holds better in turns and gets me on plane quicker. Cruise speed is better also. 454/BravoI....my top end is still 38mph on gps, Mike.
 
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CV-23 said:
I run a 4 blade Merc stainless on my 270. It holds better in turns and gets me on plane quicker. Cruise speed is better also. 454/BravoI....my top end is still 38mph on gps, Mike.
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Mike although my application is a litte different, I was wondering how much pitch you dropped if any going from 3 to 4 blade. I currently have 2 Quicksilver 13.5 x 19p that are nicked and was thinking about a switch to 4 blade. Powertech 18". rpm is currently maxed out at 4200. Merc range is 42-4600. planing at 3000 doing 24 mph and 3200 about 28 mph with 39 mph at wot. Not bad numbers but looking to get a little better hole shot and mid performance. thanks Ro
 
Factory three blade stainless was 19P.....current 4 blade is 17P. Same 14.25" diameter.
BTW....I run a 14" Merc 19P three blade stainless on my CV-23. It's a light weight 23ft boat that runs 56mph on gps with a 5.7L Factory roller motor, Mike.

MVC-016S.jpg


MVC-013S.jpg
 
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I actually never thought of going from the current 3-blade stainless on my twin 4.3 Alpha I Gen II drives, but I sure would love to get a bit more hole shot while maintaining my cruise speed at lower RPM or increasing the speed at the same RPM. Hole shot is my biggest issue, especially with a few a couple of extra guests in the cockpit. Anyone done this on a 280 or larger with twins? I assume the advantage would apply there too....?
 
Hey Gunn, didn;t you remove the stops on the trim cyclinders last year? I believe this allows the drives to be tucked in further. What was the final results?
 
Hill marine now has 5 blade props.... Very curiouse to see the results from those. Soon it will be a frisbee with a couple little holes pushing your boat. Take alook it looks kinda funky
 
Bucit said:
Hey Gunn, didn;t you remove the stops on the trim cyclinders last year? I believe this allows the drives to be tucked in further. What was the final results?
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I did do that. I wrote up the results in that thread where I asked about doing so. Can't seem to find it at the moment... It made minimal improvement. Just a bit...I'm looking for all I can squeeze out!

Xplicitlnck said:
Hill marine now has 5 blade props.... Very curiouse to see the results from those. Soon it will be a frisbee with a couple little holes pushing your boat. Take alook it looks kinda funky
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Well...over the last decade or so they've made 5-bladed helo rotors, and 5-bladed props, so....there are benefits I guess.
 
Don't rule out composites. I went from a 3 blade Al prop to a 4 blade Piranha on my Regal 2465. UNEFFINGBELIEVABLE change. Less unsprung weight. Better...time to plane...MPG...GPH...cruise speed...speed to remain on plane.........

1/3 the cost of stainless and knowing that when (not if) I smacked something with the prop, the blades were $22 each and replaceable in the water and no shaft damage.

i wish they had an inboard version. I'd be 1st in line.

For the record, I have no affiliation with Pirahna nor any financial interest in them.
 
Five hundred and thirty dollars later, my four blade stainless props are inbound.

Why did I open this thread????????????
 
Need for speed?
 
magstang1 said:
Five hundred and thirty dollars later, my four blade stainless props are inbound.

Why did I open this thread????????????
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I can't specifically blame this thread but it did cause me to do an eBay search and my 4-blade prop should be on it's way soon.
 
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