Hill 4 blade props

Stodge

There was a lot of buzz about the Hill Marine 4 blade props.  I have some questions for those folks who made the change.  

1. What was the change in pitch?  Did you go from a 22 pitch 3 blade to a 20 pitch 4 blade?

2. What was the difference in GPH/MPG making the change?

There are some reviews that are glowing but I'd like to hear first hand if these are miracles or snake oil.

Handymans342

I went to the 20 pitch 4 blade. MPG went up a bit because I was able to maintain a lower speed plane. My mpg was 2.5 at cruise around 24 mph. Diesels dont forget

Black_Diamond

I went from 22P to 20P. Not much of a gph change, but significantly more stern lift. I do not even have to trim my drives. I will say the engine noise was significantly reduced. 100% satisfied with them!

Dream_Inn

Well, my boat is a different beast than what you have, but yes I reduced pitch and have some mpg change and significant stern lift and on-plane time reduction.  Absolutely love them!

Stodge

According to the Hill Marine site you don't have to change pitch.  So did you make the change on your own or on their advice?

Handymans342

Let them advise. Dont want the motors over revving

zaverin1

Normally going from a 3 to a 4 blade you drop pitch.
same goes if you go from an aluminum to ss

MojosBoat

I am interested in the same set of props but am at a loss at to what pitch. I have no idea what I have on our 342.  That was the one receipt that the previous owner forgot to include. and we never got it from him. It is supposed to have new props when I bought it last year. I cruise at about 3700 rpm and 26-27 mph now. Planes out ok but I think it could be better. I have the twin 5.7 MPI B3 set up. 

Handymans342

Should be stamped on the props

MojosBoat

I figured it is but haven't been able to see it on there since our boat is always in the water. We plan to pull it this winter for service and anodes so I will look then. 

reneechris14

@MojosBoat at that speed and RPM I say you have 22 pitch props Stodge has 24's. Me personal would stay with 22's 

J3ff

Black_Diamond said:

I went from 22P to 20P. Not much of a gph change, but significantly more stern lift. I do not even have to trim my drives. I will say the engine noise was significantly reduced. 100% satisfied with them!

Did exactly the same and it produced the same. Trimming the drive does nothing now. Motor is not working nearly as hard. 

Stodge

I'm actually going back to 22p.  The poor girl struggles to get on plane.  Not revving high enough at WOT either.  I'm doing 27 MPH at 3250 RPM once she's up though.  

McGarnicle

Been wanting to make this change as well, currently have 24p on my 342, it could be better getting out of the hole but its not horrible. I just keep hearing they're better at maneuvering around the dock and slow speeds. I'm definitely not getting those cruising speeds like @Stodge though, I'm usually around 24-26 MPH at around 34-3500 RPMs 

downunder

i was at a local boat show {Australia} early this year and was at the Mercruiser booth and on display was a combo 4 and 3 blade prop for the bravo 3 stern drive. It was a Mercruiser part number. They admitting that many of the early cruisers were over propped. My 340 FV was way over propped with 24p props and 260 hp tbi engines. I had already contacted Hills and then i spoke with the local Solas distributor at the same show and they gave me a good deal on a combo 4 and 3 blade 21p.

What a change, before i was really struggling to get on the plane now it just jumps up and you are away and way quieter and engines are not working as hard. I am not worried about max speed or mpg. Its the way to go. Here is a pic of the props  with numbers shown.

Stodge

McGarnicle said:

Been wanting to make this change as well, currently have 24p on my 342, it could be better getting out of the hole but its not horrible. I just keep hearing they're better at maneuvering around the dock and slow speeds. I'm definitely not getting those cruising speeds like @Stodge though, I'm usually around 24-26 MPH at around 34-3500 RPMs 

Could be weight or a number of things.  Could even be that my vessel view is lying to me.    I have a feeling that when my outdrives were re-built they may have changed the gear ratio from the original.  

John342

Stodge said:

I'm actually going back to 22p.  The poor girl struggles to get on plane.  Not revving high enough at WOT either.  I'm doing 27 MPH at 3250 RPM once she's up though.  

I just bought 342 6.2, B3 2.43:1 Ratio, 22P Mecruiser 3 Blade. Only been in it 1 hours since i bought it but NOT HAPPY with cruise speed. 4200rpm 25/26 mph! Looking for @McGarnicle or @Stodge cruise speeds! WHAT'S UP?

NOTE: Survey said Tachometers are 300rpm too high!

raybo3

John342 said:

Stodge said:

I'm actually going back to 22p.  The poor girl struggles to get on plane.  Not revving high enough at WOT either.  I'm doing 27 MPH at 3250 RPM once she's up though.  

I just bought 342 6.2, B3 2.43:1 Ratio, 22P Mecruiser 3 Blade. Only been in it 1 hours since i bought it but NOT HAPPY with cruise speed. 4200rpm 25/26 mph! Looking for @McGarnicle or @Stodge cruise speeds! WHAT'S UP?

NOTE: Survey said Tachometers are 300rpm too high!

When you say 4200 rpm are you accounting for the 300 its off? 4200 rpm should be 35mph or a little better IMO. 

McGarnicle

I agree with @raybo3, 4200rpm should be 35mph+. My cruise speed is around 25-27mph at around 3300-3500rpms. 

Stodge

I cruise at around 27-28MPH at 3250 RPM normally.  But that's with 3 blade 24 pitch props.

reneechris14

@John342 are you sure about the 2.43:1 ratio
I cruise at 30mph at 4000+- rpm with 5.7 b3 2.2:1 22 pitch prop stock. I woukd think with the 2.43 the prop could go to 26 pitch with 6.2. So you must have a great hole shot but top speed of say 30mph and it will probably red line if not carefull.

J3ff

I am also at 28/30mph at 4000 rpm.. in a 270

John342

I went on 4 hour round trip Saturday. After playing with everything I ran 4200-4300 (3900-4000rpms if survey was correct) at 28-29ish. Boat feels better at 30-32mph but I have to run rpm's up 300 more. I don't like turning this many rpm's if I don't have to. TRIP SPECS - (8 people, full fuel, full water. No problem getting on plane, didn't have to use planes.) ALSO i think i have vibration coming from Port Props. So something sounds off.

John342

reneechris14 said:

@John342 are you sure about the 2.43:1 ratio
I cruise at 30mph at 4000+- rpm with 5.7 b3 2.2:1 22 pitch prop stock. I woukd think with the 2.43 the prop could go to 26 pitch with 6.2. So you must have a great hole shot but top speed of say 30mph and it will probably red line if not carefull.

2.43 is what is on survey paperwork. I can run all the way to 5500rpms to 39-40mph. That's it! Hole shot is great as far as i can tell.

J3ff

Let me know what you choose to do. On my 270 4200 at 30 sounds about right. 

LaRea

@John342 was your survey a haul-out survey so you know the bottom is clean?

John342

@LaRea @reneechris14 - I verified the 2.43 via pictures from the survey. @LaRea Yes it was haul-out & the bottom job is new. HILL PROPS ARE A DONE DEAL. They advised me that the 2.43 ratio was probably because the boat was setup for high altitudes possibly.  10% gear reduction so I can run a 10% more prop. So I ordered 4x4 24P Hill Props! He said that should be the perfect setup.

Handymans342

You will be amazed at the difference. 

reneechris14

That is a good reason for 2.43 most all have the 2.20 drive. Still think you sould go to 26 pitch but the 4 blade 24 will definitely make a hugh improvement. 

reneechris14

I only say 26 pitch because to get to 3800 at 30 mph if my math skills at right. Do agree the boat fells better at 32 mph. Hole shot vs cruise speed.

John342

@reneechris14 - Hill Marine advised me to go to 4x4 24p. They have an exchange program. So I can try it and if I need more I can exchange them. I'm in fresh, brackish & salt water so the water density changes. But I'm at sea level also. Also Don't want to lug the motors down!