Bravo III and 496 MAG.....Change over from 3/3 26P to 3/3 24P? 2009 270 SLX Thoughts?

[RichardS]

Have a situation that may lend itself to an interesting and beneficial outcome, or maybe it's a dumb idea....you guys tell me!

My survey recommended reconditioning the props because of a small crack on one blade and a couple nicks on others. Let me say the sea trial showed no evidence of issues due to prop damage, so how bad can it be?

Anyway....if I do have the props sent out for reconditioning, obviously, I won't be splashing the boat until they come back, and needless to say, it's a busy time of year for that shop.

A buddy of mine offered a solution, but I need to know I won't damage the engine in my fervor to get the boat in the water!

He is offering me a set of Bravo III 3/3 24P props, in very very nice shape. They look beautiful, and so of course I am tempted to install these and use them until the 26P props come back.

I know my RPM's will increase. I know my top speed will suffer. The question is, how much on both? Enough RPM increase to over-rev the 496 MAG and do damage at WOT? Enough drop in top speed that I won't enjoy the boat?

I know my hole shot will improve, but that's not real important to me. I'm more concerned about engine life and handling characteristics on the water.

I'm wondering what YOU guys would do? Should I try them and see? Is there a real risk involved? Even if I don't hammer the throttle, I am still concerned about running at a consistently higher RPM than what was intended, if in fact that's what I can expect, or is that just a factor at WOT?

Guess I am hoping some of you guys have experimented with props on your own 496 engines and have some useful intel.

My buddy even suggested I could trade them off for another 26P set if I wanted to do that and got the opportunity. Is THAT the best option? (Could sell and buy a used 26P set I suppose) He's a good friend who is trying to make up for some favors I did for him, although I never expected or wanted that, but I really do appreciate his help now!

What's my best course of action?

Looking forward to hearing from you guys!

 

[paulswagelock]

Re: Bravo III and 496 MAG.....Change over from 3/3 26P to 3/3 24P? 2009 270 SLX Thoug

I have the same boat and engine. I just installed a set of 4x4 24 pitch props to replace my 3x3 26 set. My wot was 4600 rpm so I had a little room to go down in pitch.

you will not damage or hurt anything. Watch your wide open throttle rpm to see where it climbs to,and keep it below 4800, though there is a rev limiter that will do it for you. Put them on, enjoy the boat.

 

[Dieseljeff]

Re: Bravo III and 496 MAG.....Change over from 3/3 26P to 3/3 24P? 2009 270 SLX Thoug

I would guess the 2"s in pitch will raise your RPMs about 300-400 RPMs
I went from 24 to 22 props and WOT went from 4100-4200 to 4600.

I did it because of a better hole shot and because my engine sounded like it was straining under 3500 RPM.
I now can cruise at 3200-3300 RPM and the engine sounds relaxed.

Different boats...different outcomes...



Jeff

 

[RichardS]

Re: Bravo III and 496 MAG.....Change over from 3/3 26P to 3/3 24P? 2009 270 SLX Thoug

I have the same boat and engine. I just installed a set of 4x4 24 pitch props to replace my 3x3 26 set. My wot was 4600 rpm so I had a little room to go down in pitch.

you will not damage or hurt anything. Watch your wide open throttle rpm to see where it climbs to,and keep it below 4800, though there is a rev limiter that will do it for you. Put them on, enjoy the boat.

Jeff.....you're right....different boats, different outcomes, but something can still be learned from your experience.

BUT......when there's a guy with the SAME boat and SAME engine.....!
Paul, Correct me if I'm wrong, but isn't the protocol to drop prop pitch when going from 3/3 to 4/4? So will my results be the same as yours? Probably not, right? But then, as you said, there's the rev-limiter I wasn't considering so that's a very good point and should lessen my anxiety about damage. Still....the boat should be revving higher to achieve the same speeds, correct? So that's a higher fuel usage, and more engine wear, at what benefit OTHER than the faster hole shot? Or am I completely off the wall in my understanding of prop size and how it impacts performance? If so, don't hold back guys....wouldn't be the first time or the last I didn't know what I was talking about, and in fact, this whole thread is intended to enlighten me a little about props and the opportunity, if this is one, presented to me.

I appreciate anything you guys what to share or suggest here!

 

[Lazy Daze]

Re: Bravo III and 496 MAG.....Change over from 3/3 26P to 3/3 24P? 2009 270 SLX Thoug

You are in COMPLETE control of how high your revs get simply by moving the throttle. But if you happen to be driving the boat with a blindfold and earplugs, the rev limiter will keep things happy. No issues, especially going down in pitch. I'd be more concerned if you were going UP in pitch. The difference in fuel usage is negligible. Increased engine wear is even less so - basically a moot point.

We don't do our own prop repairs - we send them out to a prop shop. But it's always a one-week turn-around... maybe you'll get yours back sooner than you think?

Definitely get them done. Just because you can't feel/notice anything at the helm, doesn't mean that everything is A-OK. Small vibrations can eventually take their toll on the drivetrain/engine.

 

[paulswagelock]

Re: Bravo III and 496 MAG.....Change over from 3/3 26P to 3/3 24P? 2009 270 SLX Thoug

When going from 3x3 to 4x4, you keep the same pitch if the original set is cupped (mine are) and you are happy with the original rpm. The 4x4 have one prop cupped, so it does affect rpm if the original props are not cupped, and most elite series are not. My OEM props from sea ray are cupped though.

 

[tdgard]

Re: Bravo III and 496 MAG.....Change over from 3/3 26P to 3/3 24P? 2009 270 SLX Thoug

Use them. You won't do any damage unless you go driving around sitting on the rev limiter. Sure the boat won't be as fast, as efficient, whatever else, but it will move-which it won't if you don't put them on while yours are being repaired. Think of them as a space saver spare tire for your boat.

 

[paulswagelock]

Re: Bravo III and 496 MAG.....Change over from 3/3 26P to 3/3 24P? 2009 270 SLX Thoug

Took mine out with the new 4x4 24pitch. Ran great. Max rpm was 4750- perfect.

 

[RichardS]

Re: Bravo III and 496 MAG.....Change over from 3/3 26P to 3/3 24P? 2009 270 SLX Thoug

Well, as it turned out, the seller not only agreed to have the props recon'd, the dealership who was brokering the boat got them out, and back on the boat, with a 72 hour turn-around. So I didn't have to experiment with the 24's. I am thinking about selling them (I got not one but TWO sets of Bravo III 24P props from a buddy of mine, if anyone is interested!), and buying a 4-blade set to try.

Anyway, actually FINALLY took delivery today! More about THAT in another thread!!

 

[mnm99]

Re: Bravo III and 496 MAG.....Change over from 3/3 26P to 3/3 24P? 2009 270 SLX Thoug

Was there a problem hitting your rpm with the 26? If not why loose mph and gain rpm? Check the classifieds here. I have a nice 26p set for sale cheap.

 

[paulswagelock]

Re: Bravo III and 496 MAG.....Change over from 3/3 26P to 3/3 24P? 2009 270 SLX Thoug

The ideal prop hits your max WOT RPM based on the engine recommendations.
The 26P props held my max RPM to 4400 or so, which can cause the engine to lug and work a bit too hard. Will it hurt anything - maybe.
This is a result of bottom painting increasing the drag a bit - I knew that going in. If I don't paint, i get growth and slime that is far worse than the ill effect from the bottom paint. So, I opted to drop a pitch to put me back in the sweet spot.

 

[RichardS]

Re: Bravo III and 496 MAG.....Change over from 3/3 26P to 3/3 24P? 2009 270 SLX Thoug

The ideal prop hits your max WOT RPM based on the engine recommendations.
The 26P props held my max RPM to 4400 or so, which can cause the engine to lug and work a bit too hard. Will it hurt anything - maybe.
This is a result of bottom painting increasing the drag a bit - I knew that going in. If I don't paint, i get growth and slime that is far worse than the ill effect from the bottom paint. So, I opted to drop a pitch to put me back in the sweet spot.

Paul, so, since we have virtually identical boats, (yours is a year newer of course), and mine is also bottom-painted, I guess I will face the same experience you did. But you didn't just drop a pitch, you switched over to a 4 blade set, so it's a whole different animal. Probably a much better result than I would get from just installing the 24P Three Blade set I already own. It sounds like I need to duplicate what you did. Same boat + same drive train + same bottom=same result, right?

I'll post my two sets of 24P's for sale here and maybe the proceeds would take me a good way towards the purchase of the set you have. After laying out the kind of $$$ I have in the last week, I can't buy any new toys for a while unless I fund them with a toy I don't need. LOL! My wife loves the boat but will she get the "need" to change out the prop set? Probably not! She'd rather let my kid's pesky need to eat every day interfere with my boating pleasure! Some women just don't get it!

 

[paulswagelock]

Re: Bravo III and 496 MAG.....Change over from 3/3 26P to 3/3 24P? 2009 270 SLX Thoug

Before you do anything, run the boat for a while, and take notes on the highest RPM you can achieve, and what GPS speed you are travelling at that RPM.
Then do the same for 3000 rpm - note speed.
You might be fine if your paint is smoother, etc.

 

[RichardS]

Re: Bravo III and 496 MAG.....Change over from 3/3 26P to 3/3 24P? 2009 270 SLX Thoug

Before you do anything, run the boat for a while, and take notes on the highest RPM you can achieve, and what GPS speed you are travelling at that RPM.
Then do the same for 3000 rpm - note speed.
You might be fine if your paint is smoother, etc.

Good suggestion. I was just telling someone in a PM conversation that my first day out, I was a little "underwhelmed".....expected more hole shot and more top end speed, but I don't think I am being fair. Yesterday was a day I wouldn't normally have been out pleasure-riding. It was really choppy, really windy, and kind of cold and a wet ride. But since I just launched the boat I had to go for a little ride before putting her in her slip.

I guess I can make a more fair judgement on a warm and more calm day, when the bay isn't swelling all over the place and blowing the boat across the channel at idle speed. It's hard to know if a boat is at it's best when the weather is fighting you every step of the way.

 

[paulswagelock]

Re: Bravo III and 496 MAG.....Change over from 3/3 26P to 3/3 24P? 2009 270 SLX Thoug

I am always more concerned with bottom end grunt and mid range oomph than top end. Every engine computer I look at has <5% total time at full speed, and that aligns with the way I boat.

The 4x4 24P props were noticeably different. The boat immediately "lifted" out of the water and on to plane, not the bow, but the entire boat. Then from 2800 rpm cruise to WOT was near explosive - push you back in your seat. Did I lose any top end - maybe, only spent a few seconds up there and was in the upper 40's mph.
The other improvement was I could make hard over turns without dropping speed or RPM, and without having the prop uncouple from the water.

After 2 hours use so far, good addition for my boat and the way I use it. Later this year I will provide an update on longer term experience/comments.

 

[RichardS]

Re: Bravo III and 496 MAG.....Change over from 3/3 26P to 3/3 24P? 2009 270 SLX Thoug

I am always more concerned with bottom end grunt and mid range oomph than top end. Every engine computer I look at has <5% total time at full speed, and that aligns with the way I boat.

The 4x4 24P props were noticeably different. The boat immediately "lifted" out of the water and on to plane, not the bow, but the entire boat. Then from 2800 rpm cruise to WOT was near explosive - push you back in your seat. Did I lose any top end - maybe, only spent a few seconds up there and was in the upper 40's mph.
The other improvement was I could make hard over turns without dropping speed or RPM, and without having the prop uncouple from the water.

After 2 hours use so far, good addition for my boat and the way I use it. Later this year I will provide an update on longer term experience/comments.

I agree 100% that losing a couple MPH off the top end is a smart trade-off for the way we do most of our boating. My experience, as far as day pleasure boating, parallels those engine reports you've seen. (Mine from my survey was even less than 5%, considerably less.)


So it sounds from what you've experienced so far you made a great choice! Please provide updates when you can!