Best Slalom Prop.......Acme 422 vs. 612 (or 470?)

[asd]

Has anyone got any experience with these two props?

612 (12.5x15.25, 3-blade)
422 (12.5x15.50, 4-blade)

I just picked up a 612 and I have a 422 on the 92'SN now. I plan to record rpm's at all the ski & board speeds that we use and then switch props and compare. i'll post the results.

I've heard statements like; "The 3 blade has a better ski wake" or "the 4 blade is smoother" but I thought I would would ask the PN crowd what they know about them in order to figure out which one stays on the boat.

Also, I see the 470 talked about frequently but the 612 seems to have almost the same specs as the 422 with the only diff being .25 extra pitch which should bring the rpm up a bit but not as much as the 470. (470 is supposed to run 200rpm more than 422...?) Any thoughts?

SETUP: 50/50 ski-wakeboard (92 SN w/240hp, 1.23-1 trans, PP Stargazer)

I think props should have their own forum on PN....how do we get that done?

[M3Fan]

RE: Best Slalom Prop.......Acme 422 vs. 612 (or 470?)

I don't have any experience with that prop on your hull but I've tried several props on my 2000 SN and the 422 is still the winner for me. It's just super smooth and quiet. I have a 612 and it seems to be a "noiser" prop. For me, smoothness is the #1 priority. I don't need to drag race the boat so a half second faster out of the hole does nothing for me. The 422 makes the boat feel like it has an electric motor, and that's the #1 key for me. The RPM range offered by the 422 is exactly what I want as well- right at about 4950 WOT with nobody in the boat but me. In the "sweet spot" slalom speeds in the mid 3000 RPM range, the 422 is just butter. My 612 is currently sitting in a box as my spare.

[NCH2oSki]

RE: Best Slalom Prop.......Acme 422 vs. 612 (or 470?)

I agree 422 on my sport and my 99 ski nothing was better. I have no experience with the 470. A general rul is more rpm at the same speed will be a "stiffer or harder" pull. so the 470 should be a disadvantage vs the 612 or 422.

[asd]

RE: Best Slalom Prop.......Acme 422 vs. 612 (or 470?)

Good point... I do remember being amazed at how smooth & quiet the 422 ran compared to the stock Federal. Sounds like you give some of that up with the 3 blade....

[wilsron]

I have a 1997 snob, and have oj 14x164blade, as well as acme 422 and 612. I am running the 612, which is not as smooth, but turns about 150 revs less for slalom speeds. The 422 was smoother, but still turning more revs than I would like. I couldn't tell much difference in wake, or power out of the hole

[asd]

I would have thought the 612 would turn more rpm...I thought the guys at acme said that but I may have been mixing it up with the 470 which I know spins fast.

I'm In MN and the wind has been a blowin' so no testing yet. I'm still planning to test and post results.

[cuda1]

This is interesting discussion. I now own a '98 SN. My experience has been older boats. Yet, this boat has a deep base vibration that get worse under power. Possibly this is due to prop. What do you think?

[asd]

Cuda, any vibration when under power is usually related to the parts that are turning! (prop & drive shaft) I would start with the prop...sometimes they can look good but still be slightly bent.

[Hlymons]

how does the 422 compare to the stock prop on a sport(HCH2)?

[east tx skier]

Another vote for the #422. I talked with Bill Weeks about it before I bought it. I asked him about the 3 blade as that's what they'd recommended for my old 205. Bill said that the 422 was specifically designed for slalom and the TSC era 196. I don't know how that carries over to your 92, but with that, I bought the 422, which was, of course, a great improvement over the 4 blade stock OJ. Smoother and, in my experience, it softened up the long line wake a bit.

[AirTool]

I just replaced a 422 with a 470 on an 06 206. I too plan to make a chart of rpm vs speed for each prop...but couldn't get the 470 data on Friday. It was too windy and I had guests with me. Here are my observations:

1. Hole shot was better with the 470 (as Bill Weeks suggested). I had a lot of bow rise, though. Not sure why. Maybe just a lot more punch. I'll double check bow rise when I put the 422 back on.

2. Didn't check top end...though Bill says 470 will yield a higher speed than the 422. Probably because a 3 blade is more efficient than a 4 blade. I will say that at faster speeds...changes in speed, especially slowing down, were a lot smoother with the 470 than the 422. The 3 blade just doesn't bind to the water like the 4 blade does ....which makes much smoother speed transitions. Smoothness here may not be a good feature for the slolam course. A firmer prop "grip" you might say should be better.

3. I didn't notice the noise difference due to onboard noise makers.

4. The one thing I did not like about the 470. If I punched it in a tight turn....I got nothing. The three blade would just not bite in the tight turns. As everyone probably knows, if you punch a DD in a tight turn, you get immediate response. The boat flattens out and gets on it. That was not the case with the 470. I'll check it again alone next week. With all the tiny passengers in the boat, I was a little reserved. But I noticed a big difference. The first time I did it...I had planned to impress my buddy....it felt like only 6 cylinders where firing....and the stunt flopped.

AirTool

[AirTool]

I wonder how a 654 compares to 422. It is the same except 15 pitch instead of the 422's 15.5 pitch.

Would you even notice without charting the tach/speed?

AirTool

[east tx skier]

On my old acme 3 blade, lower pitch meant a little more kick out of the hole and a touch off the top end.