Prop choice OJ 310 or Acme 541

[Dano]

Is anybody using these props with a 1:1 transmission and an older carbed boat? I'm wondering if the OJ is worth the extra money? I know these are the recommended props from each manufacturer as I've spoken to them already. The OJ really doesn't have a lot of info available and the acme is either the best thing since sliced bread or is commented as being over hyped with thin blades. With both manufacturers being the top choices, I imagine they are both quality products and the negative comments are unfounded. Can anybody offer some more insight?

Thanks,

[ALPJr]

We had a great experience with Eric at OJ when buying a prop for our 92 PS190 (slot). Went with a cnc’d OJ 4 blade that reduced the rpm’s by ~150 at 34 mph and softened the already tiny wakes just a tad.

[DW]

Using basically the same Acme prop although for a different boat (1.125" shaft) and results are good. The CNC nibral props are very smooth and with the extra blade area on the Acme have good water grip, hence a good holeshot with a 3 blade. I can't give you an OJ v Acme comparison as I have only run through a series of Acme's on my particular boat. Both companies are very good with customer call feedback.

 

I read with interest any direct brand to brand comparisons, in particular any comments on wake effects the person(s) notice. It does appear that slowing down the shaft speed seems to soften the wake albeit maybe only a small amount. That has been my testing experience. Having said that, it could be due to moving the engine speed to a lower power point in the curve which 'softens' the pull, simply questioning my own analysis.

Hopefully, others will chime in and add to the topic.

[MDB1056]

Timely topic. My brother in law just went from OJ to an ACME on his 73 Nautique. Did a number of before and after test runs to be able to note differences in acceleration and speed. The texture fins of the ACME made a marked difference in acceleration, and he said it had less vibration. He's sold. I'm still running stock OJ on my 92 Hydrodyne Comp and have no complaints. The ACME is intriguing though. Another ski buddy has one on his 86 MC and swears by it having a much better pull. I tend to believe the boat owners on results. FWIW

[Mick04]

Years ago I had a 93 Mastercraft, (carbed 285hp, Perfect Pass). I was running an OJ 4 blade, can’t remember model #. Pull was smooth, but seemed kind of “soft”. Eric at OJ helped me choose a newer design CNC 3 blade that increased RPM a bit, but gave a much firmer pull. Lost a few mph off the top end, (went from 47 to 44 tops) but it was worth it for the feel at 34mph. Great customer service from Eric.

That being said, my ski partner has had nothing but ACME on his last 3 Ski Nautiques and has no complaints about them either.

[skimtb]

I believe they are both good. There have been 1 or two decent comparisons on MC Teamtalk a while back.

Plenty of people love the 541.

Plenty of people love the OJ CNC.

Based on what I thought was the beat comparison, I tried OJ 3 and 4 blade CNC in a 94 MC. I thought the 3 blade was a bit better at 22 off and kept it. Great service from Eric at OJ.

 

I had zero concern about holeshot, top speed or rpm (they were similar anyway) just ski wake. If it matters, the 4 blade had better holeshot, but I don’t get why people prioritize that, I’m not racing, unless your lake is only 1500’ long...

 

Having said that, it wasn’t a HUGE difference.

In the end, I think a modern CNC prop for either will give you a good smooth result and will certainly not “hold you back” from progression.

 

I’d call Eric, tell him what you have and want to do and go with what he says, which may or may not being trying two props.

[Dano]

@Mick04 do you remember how much your RPM's increased at 34mph? was that boat a 1:1 transmission or was it a powerslot?

 

[Mick04]

Dano, It was a 1:1 tranny. RPM went up about 150 @34mph. With the 4 blade it was typically right about 3400, with the newer CNC 3 blade it was 3530-3550 for me to get good times with PP v6.3 (225lbs, 28-35 off). Eric said the 3 blade was a lower pitch, but actually more surface area (the blades were huge) and a different cup shape compared to the 4 blade.

[Dano]

Thanks @Mick04 I’m leaning towards The OJ. Seems like everybody who’s had one has been satisfied.

[ReallyGottaSki]

I don't have the oj equivalent 3 blade but the oj 4-force and the acme 541.

Both are great.

The acme is more linear 1:1 to rpm independant of loading and the oj launches harder but rpm can differ with loading. Tops out less due to 4 blade parasitics.

Both give good wake and spread the propwash energy wide for minimal roost, and both ski very well

 

[Dano]

Update: I went with the OJ 310 (13x11.5 CNC 3 blade) Finally had a chance to try it today. I am very impressed with it. Compared to the stainless steel 13x13 3 blade i took off. The OJ is absolutely amazing. Hole shot is night and day better and throughout the RPM range the boat just feels more responsive. If I didn't know better I'd swear somebody had added 50hp to the motor. It really is that impressive. Haven't skied it yet but I'm looking forward to it.

[Alberto Soares]

Great to hear that @Dano, living in altitude of 4300 which consumes about 15% of our engines power, I noticed that a reduced prop, 11.5 or even 10.5, makes a lot better skiing as it puts the engine in a better tork range, thus, less variation on engine RPMs and a firmer and constant pull.