www.iFourWinns.com

My local dealer will sell me a new 4 bladed volvo 14x21 pitch aluminum prop for $150.

I'm in the market for a 21 pitch propeller, the current 19 pitch WOT is too high (5000) and I would like to raise my cruise mph. Is there any benefit to a 4 bladed prop in my application instead of just getting the standard 3 (just general cruising, no towing).

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1981 Columbia 8.7
2015 Yamaha FZR - 87mph - sold
2006 Yamaha GP1300R - sold
2003 Chaparral 215 SSI - sold
2009 Stingray 195CS - sold
2000 Four Winns H180 - sold
1976 O'day Daysailer II - sold
Rick's Four Winns H180 Mods/Upgrade Thread

It will handle better at slow speeds.
How fast is that thing if you're getting 5000 rpm
out of a 19" ?
See if he'll let you test it.

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2002 Horizon 190 5.0gl

From what I understand ric, that 4 blade should do just what you are looking for. It might not be as fast as a 3 blade for top speed, but mid range cruising should be a bit faster and more efficient.

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2009 H180 w/3.0 Merc
Homebuilt Minimax Hydro
2011 Zodiac Cadet 310

Right now I GPS 39-40mph at top speed with the 19. I'm not looking for more top end (I never take my motor above 4k usually), I just want faster cruise at 3200.

Doing the math the 21 should give me 5-6mph faster, as if I was at 3800 with the 19.

_________________
1981 Columbia 8.7
2015 Yamaha FZR - 87mph - sold
2006 Yamaha GP1300R - sold
2003 Chaparral 215 SSI - sold
2009 Stingray 195CS - sold
2000 Four Winns H180 - sold
1976 O'day Daysailer II - sold
Rick's Four Winns H180 Mods/Upgrade Thread

The issue with changing #blades, and large pitch changes is as blade count goes up, prop diameter goes down. Case in point, my 3 blade 19P is about 15 3/8" dia and gives me 51 MPH at 5200 RPM. My HiFive (5 blade 21P) is 13 5/8" dia and gives me 50 MPH at 5200 RPM. The 5 gives much improved hole shot, and better throttle response in the low-mid range for my Prefect Pass cruise control, but is definately not for top-end or cruising.

I agree that you 4 blade option should be a good prop for your set-up as far as speed and RPM, and at a fair price. You will feel in improvement in the bottom end, but don't think you will increase your cruise speed, or top end. I believe you would see your most desired performance (no tubing, skiing, etc) from a 3blade 21P, or even 23P. But keep in mind, even going from the 19P to a 23P you are only going to change top end by about 5 mph.

IMO, if you ain't over-revving it and getting the otherwise desired performance, leave it alone!

It soulds like you have already used a prop slip calc.



hope that helps!

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Walt B
"Debt-Charged"
Black '07 H210SS
6.2L Bravo One turning a 21P HIFive
Wakeboard Tower with Perfect Pass Stargazer version
Missouri River; Kansas City, Mo.