High five vs revolution-prop question

[PBJT]

Hi all....I am new to prop boats. I left the jet boat seen a few years back and just purchased a 2009 Rinker 192 Captiva with a 4.3 V6 Merc MPI 220 hp. I purchased it new but my sales person did me a "favor" and installed the prop he would have wanted on it if it were his

So here is what I have. A alluminum merc 14.25" 3 blade 21P with a final drive of 1:81

It is fuel injected so I am rpm limited and have a warning alarm going off at 4950 rpm. I can easily cruise and hit 4950 rpm with the annoying alarm, so I have to back the throttle off untill the alarm quits and rpms drop. My speedo reads 50 mph (a little more if the boat is light a little less when 6 or 8 people) My hole shot is pretty decent with a tuber and 2 adults in the boat but is horible with much more after that.....is this normal?? I do expect to install smart tabs in the spring to help the hole shot.

With this info my question is....PROP purchase time. I was going to just order a High five 21. But with my max rpm so easily achieved I was thinking going a step faster. High five 23 thinking the extra 2 blades over my allum 3 blade and smart tabs the hole shot may be even better. OR what about the Revolution 23? Or do you guys who "know" have a better idea....I am a good listener/reader

Oh forgot....what am I mainly going to do with the boat, pull 3 tubes out the back with 3 adults in the boat but don't like loosing a good oll Daddy bow rider race with the next guy

Thanks for the read and help ehh!

Pete

 

[rndn]

Re: High five vs revolution-prop question

Pulling 3 tubes will be a trade off for you. You will like the high 5 for getting the tubes out of the water, but will suffer a lower top speed. Pulling 3 tubes at once irequires a lot of power and I think if you add pitch to allow you additional top end you will suffer and you may not be able to yank 3 tubes out of the water. I would try the 5 blade 21 inch SS prop as you should drop your rpm's. I really can't answer you with how much prop you need to add because we really don't know by how much you can over rev your motor. 1/2 inch of extra pitch may be enough.

 

[rndn]

Re: High five vs revolution-prop question

Welcome to the iboats.com boating forum!!

 

[PBJT]

Re: High five vs revolution-prop question

With the 14.25 21p alluminum 3 blade on it now I can tube 3 adults each in thier own tube with 3 adults and 2 kids on the boat...but I see what you mean since I can not briefly over rev the engine there is no telling how much more throttle I have available. I understand switching the 3 blade for the same pitch 5 blade there will be RPM and speed drop due to the extra load "grip" but if I still have available power/rpm is it possible I will not drop speed switching to the high 5 21p (since I will have more prop surface and mtr to push it) or is that incorrect thinking.

Pete

 

[rndn]

Re: High five vs revolution-prop question

You are correct if you have additional throttle to make up for the loss going to a 5 blade prop. The top end loss would only be a couple mph's anyway so I would not worry about it if I were you.

 

[PBJT]

Re: High five vs revolution-prop question

Just in case this helps here is a video of the boat with the 14.25 21P 3 blade alluminum. 3 adult tubers, 3 adults and 2 kids in the boat. From a dead stop.

http://smg.photobucket.com/albums/v70/princess29/?action=view&current=Rinker3tubepull.flv

Pete

 

[ufm82]

Re: High five vs revolution-prop question

From what I have read and been told by several, the Rev 4 prop should be ordered in a size down from what you currently have. That is, if you are hitting the limiter with the 21, you may want to go down to a 19 Rev 4. The Hi-Five will drop the WOT a bit but on my 20 cuddy I saw no drop in speed from the 21 3 blade SS I took off, but the holeshot was brutal! LOL

UFM82

 

[j_martin]

Re: High five vs revolution-prop question

From what I have read and been told by several, the Rev 4 prop should be ordered in a size down from what you currently have. That is, if you are hitting the limiter with the 21, you may want to go down to a 19 Rev 4. The Hi-Five will drop the WOT a bit but on my 20 cuddy I saw no drop in speed from the 21 3 blade SS I took off, but the holeshot was brutal! LOL

UFM82

I think you should get the 23 pitch high five, and I think you will really like it.

It's a ventilated prop, so when you blast off, it gets a little loose, letting your engine spin up into the power range. When it hooks, all hell breaks loose, which is exactly what you want when you're pulling tubes and skiiers. Once hooked up, it stays hooked up, even if it's half out of the water. On yer boat, I don't think you'll lose enough top end to care.

If you're on the limitter all the time, you are too low in pitch. It might be good to do some formal prop calculations, or see if you can hook up with a prop vendor that will let you try out a prop. Many good ones will as long as you pay for it and bring it back not having done any rototilling with it.

I run a high five on a XR4 150 on an 18' bass boat. It's a high performance ride, running well above expectations. At full tilt, mine is about 25% above the surface, and she pulls real hard into the 60's. The 5 blades also make it very smooth. Normally surfacing would kill an xr4 gearcase in a short while, because it is a light case and succumbs to tortional vibration. It's very low with this prop, even surfacing it.

Just for reference, I'm running an XR4, which develops about 165 at the screw, and a 1.78:1 gearcase. I run a 24 pitch high five for fishing (racing with a fishing pole) and a 22 pitch for pulling skis and tubes. Boat's full of folks that don't want to go fast anyway.

The black max prop was the salesman's favorite because he had to dump it somewhere. It's a pontoon boat prop.

hope it helps
John

 

[PBJT]

Re: High five vs revolution-prop question

Exactly what I was thinking now after research and reading.... High 5 23. Now a high 5 19 and a high 5 21 are both available for me at $500.00 and were both demo props with zero damage and <5 hrs use. I bet my boat was ordered in from Rinker with one of those optional "used" high 5 props and the salesman slaped on the 3 blade 21. since it was not writen in the deal.

I guess I really need to put on the "demo" high 5 21 and give her a go....re calculate the out come and decide to purchase the 21 or order a 23. Make sence? Cause the alluminum 14.25 21p 3 blade is just so much different then the high 5 to make the best decision on paper. Also my prop online calculatations rec a 23 as well for overall performance and top end with a 21 for accell only, but I never really rely on online calculators.



Pete

 

[MikDee]

Re: High five vs revolution-prop question

Good Luck with the Rinker, it is a Sharp boat! I saw your other post. A 21" pitch stainless 3blade similar to the alum one you have, will be harder to spin through water, and drop you're rpm usually, because it does not flex, or "give". It might even be a little softer hole shot, for this same reason. Top speed may be more because your expelling more water. For this reason, a 5blade prop maybe even worse for your application, unless you drop down in pitch, I'd try the 21" high five if possible, and see what you get with it.
You have a nice hi-perf hull, but it is no lightweight bass boat.
This info is from my own personal experience.

 

[j_martin]

Re: High five vs revolution-prop question

Good Luck with the Rinker, it is a Sharp boat! I saw your other post. A 21" pitch stainless 3blade similar to the alum one you have, will be harder to spin through water, and drop you're rpm usually, because it does not flex, or "give". It might even be a little softer hole shot, for this same reason. Top speed may be more because your expelling more water. For this reason, a 5blade prop maybe even worse for your application, unless you drop down in pitch, I'd try the 21" high five if possible, and see what you get with it.
You have a nice hi-perf hull, but it is no lightweight bass boat.
This info is from my own personal experience.

What is a light weight bass bote? 3 batteries, 30 gallons of fuel, 10 each of every lure known to man, 30 gallons of water in two swimming pools for the fishies, and of course, two phat phishermen.

The trick to hole shot is to get the engine to spool up into the power band. It can be done by gearing (lower pitch) and also by slippage (venting). The high five, at least the later ones, are vented.

Prop pitch should stay about the same. Stainless props are thinner and smoother, making them more efficient. High perf props usually have a little more cup, slightly slowing them down. For calculating/guessing purposes, the metal makes no difference. You're hitting the limiter. If most of your prop is there, ie hasn't been damaged severely, you're underpropped.

hope it helps
John

 

[MikDee]

Re: High five vs revolution-prop question

What is a light weight bass bote? 3 batteries, 30 gallons of fuel, 10 each of every lure known to man, 30 gallons of water in two swimming pools for the fishies, and of course, two phat phishermen.

The trick to hole shot is to get the engine to spool up into the power band. It can be done by gearing (lower pitch) and also by slippage (venting). The high five, at least the later ones, are vented.

Prop pitch should stay about the same. Stainless props are thinner and smoother, making them more efficient. High perf props usually have a little more cup, slightly slowing them down. For calculating/guessing purposes, the metal makes no difference. You're hitting the limiter. If most of your prop is there, ie hasn't been damaged severely, you're underpropped.

hope it helps
John

You don't have a heavy 4.3V6 I/O, you have a 2cycle motor as opposed to a 4cycle, and there ain't much of your hull in the water when planing by design, you may even have a pad on the hull? there's really no comparison, and yes, the metal does make a difference!

 

[j_martin]

Re: High five vs revolution-prop question

I guess it's all relative. For the relatively little power I have, and the displacement hole I have to climb out of to get a going, I find the high five to be about the best all around screw to use. As I stated above, it hooks up and stays hooked, but for starting out it ventilates and lets this little ole 2fo get a spinnin and burnin. Even for me, when I have only about 2 feet of the boat and the prop in the water at speed, the loss at top end is minimal.

hope it helps
John

 

[MikDee]

Re: High five vs revolution-prop question

I like the high 5, I think it's great, I couldn't recommend better, I just want PGJT to get the right pitch, because it's a lot of money.

 

[j_martin]

Re: High five vs revolution-prop question

Me too.

Propellers, especially the higher performing stainless ones, are seldom a fixed pitch, but rather progressive pitched. Different areas of the blade have different actual pitches. The rated pitch is as closely related to how it actually performs as can be guessed, by the experts that designed it.

The high five literature, for instance, states that you would want to choose a high five prop the same pitch as the one you're currently running assuming you're running correctly with that. If they are both running submersed, a high five 21 will allow the engine to run WOT pretty close to the same rpm as a black max 21 in good shape would. I am making the assumption his present prop is in reasonable condition. A damaged aluminum prop would probably overspin.

Based on that, I think the user in this discussion needs to prop up, at least one size, maybe more. That's why I suggested he find a vendor that would let him try one for a short spin to check it out.

hope it helps
John

 

[PBJT]

Re: High five vs revolution-prop question

Great discussion-thanks.
Obviously unless someone has the exact same boat and engine setup we are just using our most educated guess with the knowledge we have. As mentioned I am happy with top end but don't want to loose any. My hole shot is a concern with a loaded/tubing boat (no surprise with any boat really)....so maybe I need to get a set of smart tabs on it and re assess. Cause maybe a 23 with smart tabs will work but a 23 on its own will bring me back to being un-happy with a hole shot. I see we are all sure the high 5 21 will definately work but I know everytime my rpm over rev alarm goes off I am goint to wish I tried a 23. So smart tabs and a 23 is what I am going to hope for but we shall see. I will search for a demo 21 and 23 high five dealer.

Pete

 

[fossill]

Re: High five vs revolution-prop question

Gee, Its been a tad over 2 years now and you have yet to update us on how you made out. These forums are totally useless without posted "results" and or "what fixed" it.

 

[NarkoKrig]

Re: High five vs revolution-prop question

Gee, Its been a tad over 2 years now and you have yet to update us on how you made out. These forums are totally useless without posted "results" and or "what fixed" it.

^This

 

[Bob_VT]

Re: High five vs revolution-prop question

No need in trying to re-open an older post. If it was not re-opened when requested before.

Now it will be locked until the original poster requests it be opened.

Thank you everyone