Re-pitch prop or buy another one?

[dre0256]

I have a 1996 Four Winns Horizon 200, 5.0L volvo penta sx drive, 14.25X21 prop. I just bought the boat and it came with a Mirage 23P. After some tunning/looking into it the boat also came with the stock prop 21 pitch aluminum. I ended up changing props to the stock aluminum 21P since the boat runs better with it and has a better top end. My question is I was told that a SS prop (same pitch 21) will give me better whole shot and a +5 MPH, since the AL prop has more flex. Should I re-pitch the SS Mirage or just buy another prop period? My goal is to get more topend if all possible, while maintaining a decent wole shot.

Thanks

Dre

 

[craze1cars]

Re: Re-pitch prop or buy another one?

Both a viable options. Repitching relies on the knowledge and quality of the person doing the work. IF you know he's good, it works. Keep in mind your used/non-modified Mirage is worth some good cash on Ebay....so you could sell it and apply those proceeds towards whatever replacement you want. Frankly I think this is likely your most economical decision.

 

[steelespike]

Re: Re-pitch prop or buy another one?

We can tell better what your results will be if you get us your lightly loaded present wot rpm and gps speed.
also would be good to know your gear ratio usually on the outdrive.

 

[Scott Danforth]

Re: Re-pitch prop or buy another one?

for less than the cost of repitching, you can sell your existing prop and buy the one you want.

 

[Bondo]

Re: Re-pitch prop or buy another one?

I have a 1996 Four Winns Horizon 200, 5.0L volvo penta sx drive, 14.25X21 prop. I just bought the boat and it came with a Mirage 23P. After some tunning/looking into it the boat also came with the stock prop 21 pitch aluminum. I ended up changing props to the stock aluminum 21P since the boat runs better with it and has a better top end. My question is I was told that a SS prop (same pitch 21) will give me better whole shot and a +5 MPH, since the AL prop has more flex. Should I re-pitch the SS Mirage or just buy another prop period? My goal is to get more topend if all possible, while maintaining a decent wole shot.

Thanks

Dre

Ayuh,.... My Prop Guy, Don, at Don's Prop Shop in Clayton Ny. tells me that they can bend a wheel up to 'bout 1", either way,...

 

[dan02gt]

Re: Re-pitch prop or buy another one?

My suggestion is to sell Mirage and get something like a 21P Enertia (I love mine).

The Mirage will never run well on your boat. It's designed for high performance boats. Think Donzi with a 500+ hp big block.

I tested one that had been worked on my Stingray and while it ran OK you could tell my little 4.3L really don't have the balls to turn those big high rake blades. The Enertia runs much better all around.

 

[dre0256]

Re: Re-pitch prop or buy another one?

We can tell better what your results will be if you get us your lightly loaded present wot rpm and gps speed.
also would be good to know your gear ratio usually on the outdrive.

2 ppl with half tank WOT 45.1 gps mph @ 4500 rpm's. Gear ratio have no idea.

 

[hungupthespikes]

Re: Re-pitch prop or buy another one?

Dre, glad you came over here for help.
The gear ratio is the key for a good match.
1.5 and your slip will be 25% or more and a SS would most likely help.
1.8 and your slip would be 10% so your golden with the 21p AL you have.
You don't want to make a $400 mistake like the PO did.

Dan02gt gave you a good option, but without slip/gear ratio we're shooting from the hip at best.

The drive will have numbers on it. With make and the numbers, we can get to the gear ratio that we all need to help.

huts

 

[dre0256]

Re: Re-pitch prop or buy another one?

Ok I will check tom for the gear ratio and get back to you all.
Thanks
Dre

 

[jimmbo]

Re: Re-pitch prop or buy another one?

I like the Enertia too. Been running one for 6 or 7 yrs now

 

[drewactual]

Re: Re-pitch prop or buy another one?

I just went through a prop experiment with my rig, which is a similar size/displacement/design to yours...

I settled with a turbo1 22p three blade...

here were my candidates and what I got out of them, fwiw:

20p four blade Michigan Wheel aluminum 14" - I wonder if this thing was truly 20p or just had massive flex, because I hit the rev limiter on my 4.3 at 5200RPM.. It was mighty quick out of the hole, and didn't provide a lot of bow lift, or maybe it did but evened it out with stern lift.. I suggest that it flexed under power to around 18p.. I hit somewhere around 38mph, iirc, with an alpha genII 1.81:1 outdrive... I could hold plane @ 25~2600RPM and just over 15mph.. that was great for sipping fuel..

23p four blade solas amita(sp?)4 aluminum 14.25".. couldn't hit but 4300rpm.. around 43ish WOT.. slow out of the hole... mid range was strong, but wanted to fall off plane around 3300rpm/26ishMPH.. hit around 3kRPM when popping it hard out of the hole, and off idle.. it would struggle there until it bit in and planed around 6~7 seconds.. too much prop..

22p 14.25" 3blade s/s turbo1 vented with a visibly highly progressive blade- those vents are important... engine spools MUCHO faster out of the hole, nailing 37~3800RPM where the 23p would only hit 3kRPM, putting me deeper into the engines power-band, which allowed even further revving.. Hit 46~4700RPM WOT @ 45~47mph.. happy with this props geometry and those vents make a big difference.. even though it feels like it's going to drop off plane, it will hold it down to just shy of 3kRPM @ 24ish MPH... good for cruising, no?

I would be best served, if I cared to spend a few more dollars, to get a 21p with duplicate blade geometry as the 22p turbo I'm currently running... but the 22p is fine, and close enough...

^all of that to say: the game of proper propping is just as much about blade geometry as it is pitch, rake, cup, diameter- when you're dialing it in.. those vents allow me to spool up that 22p faster than even the 20p out of the hole, which allows a slightly bigger pitch to be used.. w/o those vents, this conversation would be much different..

manufacturers state the average pitch on a progressively pitched prop, but not the 'ramp' of the pitch- so the difference between two props marked the same from two different makers can be substantial- the michigan wheel, visibly, had less progressive ramp than the turbo1.. the cupping on the turbo1 somewhat matched the mw in overall height, but the ramp to achieve that height took place over a much longer distance.. tricky, no?

anyway, I just wanted to pile on some more variables you may want to take note of while making your selection.

 

[dre0256]

Re: Re-pitch prop or buy another one?

Dan02gt gave you a good option, but without slip/gear ratio we're shooting from the hip at best.

The drive will have numbers on it. With make and the numbers, we can get to the gear ratio that we all need to help.

huts

The drive is a SX cobra and I couldn't find any numbers on it!

 

[hungupthespikes]

Re: Re-pitch prop or buy another one?

Per page 99 of the link below:

http://www.fourwinns.com/upload/Documents/Catalogs/1996/FastFacts_1996.pdf

Gear ratio for a SX Cobra is 1.66,.......... 4500 rpm, 45 mph, 21p AL.... gives you a 16% slip
WOT range is 4000-4400 rpm per link.
Theoretical speed at 4400 is 53mph. even with 12% slip (below that will be tuff for your hull) will only get you 47mph.

The SS prop will get you back in the max RPM range, lower the slip, but the end result will be little for more speed. imho

If you can get a good prop match for your boat, get the boat set up just right, with a light load, then yes you could get the +5 your looking for. You will most likely be over the 4400 rpm max, but that's not a biggie for short runs.

Time to do some horse trading for that 23p Mirage.
drewactual's results with the turbo1 was a great post.
The Enertia 21p (dan02gt) would be a good match too.

Now maybe some of the prop guys will chime in. hint hint
good luck
huts
ps:
ifourwinns.com
Four Winns Boats

 

[dre0256]

Re: Re-pitch prop or buy another one?

Per page 99 of the link below:

http://www.fourwinns.com/upload/Documents/Catalogs/1996/FastFacts_1996.pdf

Gear ratio for a SX Cobra is 1.66,.......... 4500 rpm, 45 mph, 21p AL.... gives you a 16% slip
WOT range is 4000-4400 rpm per link.
Theoretical speed at 4400 is 53mph. even with 12% slip (below that will be tuff for your hull) will only get you 47mph.

The SS prop will get you back in the max RPM range, lower the slip, but the end result will be little for more speed. imho

If you can get a good prop match for your boat, get the boat set up just right, with a light load, then yes you could get the +5 your looking for. You will most likely be over the 4400 rpm max, but that's not a biggie for short runs.

Time to do some horse trading for that 23p Mirage.
drewactual's results with the turbo1 was a great post.
The Enertia 21p (dan02gt) would be a good match too.

Now maybe some of the prop guys will chime in. hint hint
good luck
huts
ps:
ifourwinns.com
Four Winns Boats

You guys are awesome thats why eveything I own I am a forum member. Thanks alot and like you said time for some trading ;-)

Thanks

Dre