Need Prop Advice for Four Winns Horizon RX

RVguy99

Cadet
Joined
Mar 29, 2011
Messages
20
Hello,

I have a 1997 Four Winns Horizon RX (basically a Horizon 180) with the 4.3 Volvo/Penta. The stock prop on the boat is a 14.25 x 21, 3 blade aluminum. I damaged it a bit the other day and want to take the opportunity to buy a better prop and keep this one as an emergency backup.

We plan to use the boat for skiing, tubing, etc and I'd like a prop with better holeshot than the original. At the same time, I don't want to lose a ton of top end because this boat only hits 40 or just over to begin with.

What would be the ideal prop for this boat given these constraints? The holeshot on the boat is weak already, as it's pretty heavy. Any advice is much appreciated, we're trying to get out on the water for our vacation in just over a week.

Thanks!
 

RVguy99

Cadet
Joined
Mar 29, 2011
Messages
20
Re: Need Prop Advice for Four Winns Horizon RX

I really need help here. All my googling and forum reading has left me even more confused than when I started. I read the following post on another thread on this forum:

"Rule of thumb when going from 3 to 4 is to drop an inch on both diameter and pitch. Typically you'll lift the bow better and have a better hole shot but the top end won't suffer more than 1 or 2 mph. That's the way mine worked out. "

From what I understand I can achieve my objectives by going to a 4 blade prop. Should I keep the pitch and diameter the same or should I drop both as indicated above? Also, should I stick with aluminum or switch to SS? I really appreciate ANY advice, I'm a newb and don't want to blow a few hundred bucks on the wrong prop.
 

Robbabob

Senior Chief Petty Officer
Joined
Jun 5, 2009
Messages
678
Re: Need Prop Advice for Four Winns Horizon RX

Hey RV Guy,

Sorry for the slow timing in getting back with you. The information you have found is correct as a rule of thumb.

Read the link, which is on the props page as a sticky, http://forums.iboats.com/showthread.php?t=287818 and provide the essential data necessary for better input.

A 3-blade will provide for best all-around performance. The 4-=blade is better for hole-shot (essential for skiiing and tubing), but you will lose a little speed on the top end. By providing the data from the link, we can give our best input to help you.

Good luck!
 

RVguy99

Cadet
Joined
Mar 29, 2011
Messages
20
Re: Need Prop Advice for Four Winns Horizon RX

Oops. Shame on me for not checking the sticky or providing all the necessary info. Here goes, with correct info this time:

1) Performance issue you are trying to correct. - LACK OF HOLESHOT
2) Current prop manufacturer, model, aluminum or stainless as a minimum. - 14.25" x 21 ALUMINUM 3-BLADE OEM
3) Current prop diameter and pitch (required). 14.25" x 21
4) Wide open throttle RPM and speed with an average load (very helpful) - 4600-4800, depending, speed unknown (boat speedo seems inaccurate at 40mph)
5) Engine/drive make, model, year, and HP - VOLVO/PENTA GL SX COBRA, 1997
6) Boat make model, year, length and weight FOUR WINNS HORIZON 18' 2400lbs
 

RVguy99

Cadet
Joined
Mar 29, 2011
Messages
20
Re: Need Prop Advice for Four Winns Horizon RX

So if I am understanding correctly, to go to a four blade I would buy a 13.25" x 20?? I haven't seen one that size on the market in my searches. From what I am reading, the four blade provides better cornering (less cavitation) and holeshot which is just what I want. Loosing a couple mph isn't going to upset me too much. Losing 5mph or more would, however.
 

Robbabob

Senior Chief Petty Officer
Joined
Jun 5, 2009
Messages
678
Re: Need Prop Advice for Four Winns Horizon RX

Something near a 14 diameter will be fine; don't drop below 13 though.

As for the speed change............ The only way to know for certain about the performance change will be with testing. Always keep in mind -- there are "rule of thumb" calculations to go by. An extra 100# battery and anchor could change the minute characteristics.

How's that for qualifying the information!?!?!? :D

Hate to say this for you.... You really can't have the best of everything. For each boat (owner), there is something to improve. For everything improved upon, something has to give. I hope you can imagine all the variances "we" boat owners want... until we become realistic! We have the boat we have and it can only do so much... then we need to upgrade.

Oh wait, it costs that much to upgrade???? Hmm, maybe our current boat is just fine :p

Good luck with yours! :cool:
 
Top