Prop Specs ONLY

[SquamInboards]

The idea is that this thread could become sticky, and act as a resource for information about props. It seems like there are a lot of people asking about props for different applications, different watersports, amounts of ballast, etc. and the same information gets repeated a lot.

So please keep responses limited to propeller-specific discussions, and tell us ALL of the following:

• Boat Info:
  
• Year
• Make
• Model
• Length
  
  
• Drivetrain Info:
  
• Engine / HP
• Transmission (ratio, e.g. 1:1)
• Prop Specs: part # and/or Diameter, Pitch, Blades, Cup
  
  
• Performance / Usage
  
• WOT RPM
• What do you use the boat for?
• How much ballast, if any?
• Difference between loaded / unloaded if applicable?
  

Did I miss anything? Is that too much information?

I'll put mine out there in any case:

Boat:
1989 Supra Bravura 21'

Engine:
PCM 351 / GT-40 / 310hp
1.23:1 transmission
Acme 1868 Prop: 12.5x14.25 4-blade .075 cup

Performance / Usage:
4700 RPM WOT with no ballast / no passengers. 41 mph.
Various watersports: skiing, wakeskating, some surfing, lots of just cruising.
Boat performs okay with 1500lbs ballast or ~10 people which is all you can fit anyway.
Prop could/should be lower pitch if I ran it loaded all the time, but I am more often with 1-2 people than loaded.

Other props I've tried:
Acme 422 ran only 4300 RPM WOT (12.5x15.5 4-bld .105 cup)
Acme 654 ran about 4500 RPM WOT (12.5x15 4-bld .105 cup)

[2500HD]

Elevation 8200ft
1989 supra saltare

Engine:
pcm 454/330hp
1:1 transmission
Acme 913 prop 13x10.5 3-blade .060 cup

Performance/Usage:
4100 RPM WOT with no ballast no people. 31 mph.
4100 RPM WOT 3 people. 30 mph
mainly surfing with 1700lbs ballast and 3 people......no problem out of the hole and can still get on plane at 27 mph.
My old oem style prop with ballast and people could not get on plane.
For my elevation, this prop rocks!!!!

[cadunkle]

1989 Supra Saltare
PCM 454 330 HP - rebuilt by previous owner unknown what has been changed or any increases in power
Velvet Drive 1:1 transmission
Acme 541 13x12 3 blade CNC .080" cup

4700 RPM WOT 43 MPH - No ballast, driver only, tank mostly full
2500 RPM 22 MPH

Boat is used primarily for wakeboarding, kneeboarding and occasional skiing
Under 2 seconds to 20 MPH
Have not pulled anyone with this prop yet, but I expect it will do just fine holding speed and pulling rider with typical ballast I run (400-800 lbs and typically 3 people in the boat. Switched from old cast OJ 14x13 hoping for some small improvements in performance and economy as per what several here have reported. Disappointed with top speed so may end up changing to another prop.

[inair]

1991 Supra Sunsport
PCM Ford 351 factory 230 HP. Currently 840hrs HP?
Tranny 1.123:1
Acme 668 4 Blade, 12.5X15.5 CNC .150 cup

Performance/Usage
4000 RPM WOT Two people in boat no ballast Full Gas Tank 43 MPH unverified

Boat is used primarily for boarding with up to 450lb of ballast and skiing.
Pulls very strong for skiing and boarding. Unknown how it would do with surf ballast.
The reason I changed props was that I couldn't seem to get the old one balanced and had a lot of vibration.
Did my research before buying. Learned a lot about prop theory but ended up buying a prop that was recommended by Nettles Props instead of the the one my calculation said was right. Prop theory says a 4 blade is less efficient than a 3 blade but easier to keep in balance. Also prop theory says I'm over propped (too much pitch and cup). But I'm happy with it so far. If I tried surfing I don't know but I hope to find out!

[Kip]

1988
Supra Mariah
21 ft.

351W 775 hours
1:1

old Michigan Wheel
14x11 .080 cup
WOT RPM 3800
WOT MPH 37
Worked ok for boarding and skiing slow to get out of the hole
We run 1600lbs for surfing and that definitely made it struggle.

NEW PROP
Acme 1225 13x10.5 .150 cup
WOT RPM 4200
WOT MPH 39
Much stronger out of the hole for boarding and skiing plus better top speed
surfing with 1600 lbs much better out of the hole and doesn't seem to bog the engine down as much. Seems to be much easier to hold speed while surfing. 2100 RPM @ 10MPH

[SquamInboards]

Thanks for contributing! I hope this thread can continue to build, and help people out who are looking to upgrade, rather than having 20 people speculating about what will work. I realized I can add another boat to this; my father in law has an '89 Comp with an Acme 1868, which is the same prop as mine but his boat is quite a bit different.

1989 Supra Comp

Engine:
PCM 351W ~240hp (bone stock, approx. 900 hours)
1.23:1 transmission
Acme 1868 Prop: 12.5x14.25 4-blade .075 cup

Performance / Usage:
4300 RPM WOT with no ballast / no passengers. ~44 mph although I have not GPS verified this.

This boat is basically a cruiser and almost never used for skiing, and never runs any ballast, ever. Usually 1-3 people on board. It has great hole shot, and fantastic throttle response throughout the RPM range.

[Wulphie]

1987 Supra Pirata

Mercruiser MIE 454 rated at 340 hp Engine is definitely tuned more for midrange torque than high rpm hp.

1:1 transmission

I originally had a 14x12 3 blade prop that I bought locally to get a base line to decide what prop setup would fit my needs the best. (the merc I repowered with is rh rotation)
The 3 blade was horrible, the slip numbers I was getting were in the 25% to 28% range and the resulting air in the prop wash made the boat drive terribly, the rudder was not very effective. At slalom speeds the stern of the boat was so loose it made it near impossible to run the course. 3,750 rpm at 32 mph.

I picked up a 4 blade solas 13x13 rh. My slip numbers are down around the 13% to 15% range now. The prop wash has so much less air that the boat tracks great and turns much better. Piece of cake to run the course, all around drive ability is improved. I think I will keep the boat, where before I was ready to sell it haha.

2600 rpm 28 mph

3000 rpm 32 mph

3500 rpm 36.5 mph

I only had 2 350# sacs loaded to do some boarding because the water was shallow but the boat pulls you up without really getting into the throttle, pretty effortless. Pulling up on a slalom ski is great because there is so little flare in the engine rpm, you can just bring the rpm up to 3,000 or 3,100 and go, no revving the engine up and then backing it down as the speed builds.

Seat of the pants tells me that this prop will probably use slightly more gas because of the additional drag in the water, but it is a worth while trade off for drive ability.

I should also add that I didn't run a wot high speed test because it was a windy trip to our ski spot and didn't want to break the boat in half haha

[Cusefan78]

1995 labrisa
Gt40 pro boss 320hp
1.1 tranny
20.5'
Acme 541 prop
49.6 mph GPS wot
No ballast
Slalom skiing
Oem prop was a 4 blade on cast 13x13
Was looking for better hole shot and top end. Gained around 5 mph

[rdvanput]

Hi all, recently purchased a 1990 20' Supra Sunsport with PCM Ford 351 factory 230 HP. 475 hrs on engine. I have the 1:1 tranny. This is the first boat I've owned, although been around boats most of my life. Still, learning a ton of new info. This is exactly the post I was looking for so thanks to SquamInboards for initiating it. I will be using the boat mostly for skiing and wake boarding and just all around cruising. I know I have a three blade prop and I believe it's OEM, but sorry I don't have other details. I'd really like to know what others would recommend for my boat and usage. Thanks!

[SquamInboards]

Hi all, recently purchased a 1990 20' Supra Sunsport with PCM Ford 351 factory 230 HP. 475 hrs on engine. I have the 1:1 tranny. This is the first boat I've owned, although been around boats most of my life. Still, learning a ton of new info. This is exactly the post I was looking for so thanks to SquamInboards for initiating it. I will be using the boat mostly for skiing and wake boarding and just all around cruising. I know I have a three blade prop and I believe it's OEM, but sorry I don't have other details. I'd really like to know what others would recommend for my boat and usage. Thanks!

How's this for a delayed response?

Looks like the user above, 'Kip' has a similar boat, and the same engine/transmission. I'd call Acme or Skidim with that info and see what they think, but I'd look at the one Kip used (above in this thread).

Then, let us know what you end up with!