Yet another Prop question?

[Fluid63]

I have been trolling these forums for info on the best prop for a 1994 Sport Nautique with the Carby, 285HP, Pro Boss eng.
From all I have read The props of choice seem to be the Acme 470 3 blade or the Acme 422 4 blade. Most of the posts
where from a number of years ago so I am wondering weather Acme have anything new we should consider?

This is my good friends boat and he uses it for recreational ski/wakeboard and a small amount of beginner barefooting,
the children are the main wakeboarders and are not using ballast yet. The current prop is a OJ 3 blade and does not a
bad job but is a little damaged so will repair for a spare. The boat has a current top speed of 47mph, but this is taken
from the factory speedo and not confirmed by GPS so accuracy is questionable. All our boating is done at close to sea level.

Thanks for any advice in advance.

[surroundsound64]

Don't know the specs of props right off, but I've got quite a but of time behind a 94 pro boss (carb.) I like the 3 blade better. Had a 4 blade for a short period of time and lost some top end and used more gas. You'll get more speed out of the carbed version than EFI.

Said this in another thread today as well.

[Fluid63]

Don't know the specs of props right off, but I've got quite a but of time behind a 94 pro boss (carb.) I like the 3 blade better. Had a 4 blade for a short period of time and lost some top end and used more gas. You'll get more speed out of the carbed version than EFI.

Said this in another thread today as well.

Thanks for your input.
I like the 3 blade props on these too, just checking if Acme had any "new 3 blades to offer since the 470 has been around a while, but I guess why mess with something that works so well.

[Mikeski]

Funny, I just posted advice on the prop question for the 211 but I am wondering what prop I should put on my 98 Ski Nautique with the 290HP carbed HO motor (Ford). I assumed the 422 was the prop but I am rethinking that now and leaning more towards the 470 after giving it some though while reading this thread. It currently has a 4 blade OJ with some damage on one of the blades (small chunk missing) so it will also become my spare once the new prop is installed. I would like the boat to pull 45MPH for barefooting if possible.

[Fluid63]

Funny, I just posted advice on the prop question for the 211 but I am wondering what prop I should put on my 98 Ski Nautique with the 290HP carbed HO motor (Ford). I assumed the 422 was the prop but I am rethinking that now and leaning more towards the 470 after giving it some though while reading this thread. It currently has a 4 blade OJ with some damage on one of the blades (small chunk missing) so it will also become my spare once the new prop is installed. I would like the boat to pull 45MPH for barefooting if possible.

I had a 98 ski carby Pro Boss and I believe it came factory with a 4 blade OJ progressive pitch prop. We never changed props as it suited our needs at the time, we could barefoot, but can't confirm the speed. I do know we could turn it to 5200 rpm. I have tried the Acme on a 94 ski with the 260Hp eng and it worked great.

Just some food for thought, I noticed in the sales brochure for 96 Correct Craft state the top speed for the SN is 46mph the Signature SN is 46.6mph and the SPN is 47.5mph I wonder how the bigger heavier boat is faster unless the minimum spec eng offered for the Sport was the Pro Boss?

I wonder about other year models?

[DanielC]

The biggest influence on speed of a boat is the wetted surface of the hull.
The hull on a ski boat is purposely kept bow down to flatten the wake. This compromises the top speed.

[TRBenj]

The 422 is the prop of choice on HO 351w powered 1.23 Ski Nautiques if you run relatively close to sea level, and are trying to prop the boat for all around use. That prop keeps you in the 4800-5100rpm range at WOT, which is right where you want to be with that motor. The 470 and other 15" pitch Acmes run about 200rpm higher, so a bit higher than you want to be (at least for all around use).

The Sport is a bit heavier and has more wetted surface, so it *might* benefit from a slightly smaller prop like the 470 to keep the revs in the same range.

The only way to be sure which prop works best for your particular boat(s) in your application, is to get some baseline performance numbers (confirmed prop make, model and size, WOT RPM with a verified accurate tach and top end speed verified with a GPS).

[Mikeski]

Back to 422, I don't want to run the higher revs, thanks guys.

[White Knuckle Rider]

I'm thinking of purchasing a sport 200v with the 409. I would like to keep the revs down as much as possible at ski speeds. Do you guys have any recommendations. Would a 3 blade produce a nicer wake at lower rpm's?

[Mikeski]

There are two ways to reduce RPMs, more pitch or more cup. What prop do you have now?

For more pitch look for an Acme 381, it will keep the revs down with 17.5 pitch. I doubt the 409 will have any trouble pushing it under a 200V. I think they may have renamed the 13.5 x 17.5 prop

For more cup you could try an acme 1161, it has more cup but still has 16" pitch. It might spin more rpms at 25-35 than the 381 but it will probably be about the same at WOT.

You can also try a 14 or 14.5" diameter prop but I didn't like what they did to my wake. Since you are focusing on skiing you might want to stay with a smaller diameter prop.

Check with the Acme guys they can be very helpful, real folks answer the phone.

Don't forget to use the Planet Nautique discount at Delta Prop, they are also very helpful.