Ordered new 4x4 props for my 270 slx B3

[paulswagelock]

So during the winter layup I noticed a small bend in one of my prop's blades. It is a smooth mis-shape, and slight enough that it needs pointed out to see. However, I was planning to send them out to have them redone to fix it. There are no local shops for me, so with shipping it would be ~$290 for reconditioning.

I have a 270SLX with the 496 and B3 drive and the original 26P 3x3 cupped props. I am a northerner, so I bottom painted the boat. Since painting, I have been slightly over propped from the increased drag, turning a max rpm ~4450, at ~47-48 mph. I do not have enough history on what this boat's top speed and WOT rpm were before painting, but just a little higher from what I remember from the test drive.

So since I was planning on having the props reconditioned, I started thinking about getting a new set at 24 pitch to bring the rpm up to the recommended WOT range, and keep these for the emergency spares so I don't lose a weekend if I hit something. Ran several calculators, and all of them come to the 24P conclusion.

I purchased a set of Ron Hill 4x4 for my last boat and had good success with them, so I figured I would try again. Pulled the trigger today and ordered the 4x4 24P props. I will report back in the spring on comparison of rpm/speed/fuel usage.

 

[jgarko]

Sounds like a proper conclusion from a logical thinking approach.... So long as the drop/lower WOT is not some other issue. Good luck!

 

[mnm99]

So during the winter layup I noticed a small bend in one of my prop's blades. It is a smooth mis-shape, and slight enough that it needs pointed out to see. However, I was planning to send them out to have them redone to fix it. There are no local shops for me, so with shipping it would be ~$290 for reconditioning.

I have a 270SLX with the 496 and B3 drive and the original 26P 3x3 cupped props. I am a northerner, so I bottom painted the boat. Since painting, I have been slightly over propped from the increased drag, turning a max rpm ~4450, at ~47-48 mph. I do not have enough history on what this boat's top speed and WOT rpm were before painting, but just a little higher from what I remember from the test drive.

So since I was planning on having the props reconditioned, I started thinking about getting a new set at 24 pitch to bring the rpm up to the recommended WOT range, and keep these for the emergency spares so I don't lose a weekend if I hit something. Ran several calculators, and all of them come to the 24P conclusion.

I purchased a set of Ron Hill 4x4 for my last boat and had good success with them, so I figured I would try again. Pulled the trigger today and ordered the 4x4 24P props. I will report back in the spring on comparison of rpm/speed/fuel usage.

Good luck. I have Hill marine also, but took me 3 tries to get the RPM right. You should be fine with that 496 though. I went from 26P 3x3 to the 24P 4x4 and lost 400rpm. I'm now running 22P and my RPM is still at the bottom end of 4400-4800 rpm. I did gain a whole bunch of hole shot, I lost 1 MPH on cruise and 3 mph on top end. over all I'm happy.

 

[Jeremygavin]

I have Hill marine 4x4 as well and they are great. Much more control around the docks and backing down. I had a cavitation problem on hard turns with my stock 3 blade props and the new 4 blades have cured that completely. I lost a few top speed MPH as well but I never run at WOT so no big deal. My cruise MPH stayed the same and hole shot was much better. I can also stay on plane at much lower speeds. Great props.

 

[paulswagelock]

Jeremy - what pitch props did you have originally, and what did you switch to? Do you remember the RPM change if any?

 

[paulswagelock]

Good luck. I have Hill marine also, but took me 3 tries to get the RPM right. You should be fine with that 496 though. I went from 26P 3x3 to the 24P 4x4 and lost 400rpm. I'm now running 22P and my RPM is still at the bottom end of 4400-4800 rpm. I did gain a whole bunch of hole shot, I lost 1 MPH on cruise and 3 mph on top end. over all I'm happy.

were your original props cupped or not? On my last boat when I switched, I went from 20p non cupped 3x3 to Hill 22p 4x4 with the cupping. I went down about 300 rpm (that was the goal) but maintained top speed at a lower rpm, and lowered the rpm at cruise (original goal) and stopped all the blow out in turns.

 

[Jeremygavin]

Jeremy - what pitch props did you have originally, and what did you switch to? Do you remember the RPM change if any?

On Hill Marine's recommendation I stayed at the same pitch, 28p as my original 3 blades. With the 3 blades I was at the top of the wot range and with the 4x4s I am at the bottom so I dropped about 300rpms. In retrospect I wish I had dropped a pitch becasue my boat is heavy and in heavy seas the engines struggle to bring me back up the back side of rollers. I am within wot specs still but at the bottom of the range, for a heavy boat I want to be at the top of the range again.