ACME 644 on SV211's

[Mikeski]

My new Sport 211 (Excalibur 330hp) came with a ACME 380 (13.5x17.5). It was too much prop and the boat was slow pulling skiers up out of the water and when all of the ballast was full with wakeboarders. I changed the prop to the 536 (13.5x16) and it was a big improvement but it still leaves a little to be desired for slalom deepwater starts with heavier guys.

Does anybody have experience pulling up big skiers with a Team Edition 211 (it comes with a 644)? Also, what is the top speed with this prop, I still intend to barefoot when there is an audience...

Mikeski

[Mikeski]

RE: ACME 644 on SV211

By the way here is my review/comparo between the 380 and 536 on my SV211 with the Excalibur 330:

ACME 380 - 13.5 X 17.5"
Nice smooth running prop, great for cruising around and going fast, slow to pull up slalom skiers, slow to pull up wakeboarders when ballast tanks full. Top speed 47mph with a light load, no accessories on the tower, in a light chop (optimum conditions for speed), 4800rpm at wide open throttle, 3450rpm @34mph, 2300-2600rpm for wakeboarding speeds (22-24mph).

ACME 536 13.5 X 16
Much quicker pulling wakeboarders to riding speed, higher rpm's make cruising at 32+ mph less relaxing, better pulling slalom starts then the 380 but still a bit slow and bigger skiers take a long time to come up. Top speed 46mph (optimum conditions) at almost 5200rpms, 3850rpms @ 34mph, 2400-2800rpms at wakeboarding speeds. This prop is not as smooth running as the 380 but some deburring might make it better.

[hsmunoz]

RE: ACME 644 on SV211

Mike,

let the boy drive the boat last weekend, and well, long story short, I have a new 644 on the way, and the old one is at the repair shop. I asked them to add some cupping to drop the rpm's to a 13.5X16 equiv,

on my boat with the 644, I didn't think I had any problems pulling up boarders, but I have no inboard history to compare it to. The 644 spun 5200 rpm at about 42mph, with 7 people on the boat and a littile chihuahua.

[jonfo]

RE: ACME 644 on SV211

What does the TE come with? I think mine spins 5000 at 40mph empty.

[Mikeski]

RE: ACME 644 on SV211

The Excalibur 330 Team Edition shold have the 644.

I took my 380 in to be tweaked. They will be putting a progressive pitch on this prop, the leading edge will be on a 15" angle and the trailing edge will be on a 17" angle. I will get it back Wednesday and run it this weekend then report back.

Something else that I have been thinking about. The Acme blades are pretty thin, I was actually surprised how easily they were to bend. This may be a good thing or bad, it's likely that they flex a little more then the old OJ blades. I also find it kind of interesting that the older Super Air Nautiques with GT-40's used to run a 14x18 OJ 4 blade, I am thinking that Ford may have had more torque then our Excalibur Chevy's. I guess only the guys running the dyno's at PCM know for sure. There seems to be a significant reluctance industry wide to show power curves for these motors.

[SGY]

RE: ACME 644 on SV211

Mikeski. the guys at Skidim have told me that the GT-40 has more torque than the Excalibur. In fact, they say that the GT-40 stays even the ZR6 in terms of torque up until about 3800 rpm. I pulled skiers this weekend with a 2001 SN using the GT-40. This was at 9000 feet. The GT-40 at that altitude feels a bit stronger than my Excalibur at 5000 feet.

[Mikeski]

RE: ACME 644 on SV211

SGY,

You confirmed my seat of the pants judgement. Where are you skiing at 9000 feet?

[jonfo]

RE: ACME 644 on SV211

I bet if we compared the bore and stroke of the Ford 351W Vs GM 350 we would see a longer stroke on the Ford.

What does 644 equate to? I think 14X18 means 14" diameter and 18 degree pitch, not sure about that though.

[Sbt3]

RE: ACME 644 on SV211

You are correct on the 14x18.

The 644 is 13.25x16, .105 cup, and the 536 13.5x16, .105 cup, the explanation that was given to me between the 644 and the 536 was a slight clerance differance in the new nautique's which is why the diameter on the 644 is 1/4 less.

If anyone is looking for a 856 13.25x15.5, .060 cup I may be selling one. I bought it this weekend and personally didn't care for the performance. The Rpm's were much higher out of the hole and overall running loaded out with 2300lbs plus 5 people was 3400 Rpm @24.5mph. Supposedly the higher rpm's out of the hole is easier on the engine and tranny. The prop was designed to do this. If I can't trade the prop I will probably look to sell it and may be able to give someone a good deal if they are looking at this prop. I only had it on for one set and it is already off the boat and back in the original box. Like new.

[clubmyke]

my 211 came with the 644 and i have no problem out of the whole... please keep in mind i have nothing to compare it to...

[maxxxhardcore]

Does changing the prop void the warranty?? If you change to a prop that the Nautique factory uses ~ACME, is this ok?? Anyone had any problems with this??

[Mikeski]

Sorry for the double thread, just wanted to keep both topics up to date...

Another update on my prop "experiment"...

My Acme 380 (13.5x17.5) was repitched to a variable pattern with the leading edge of the blades at 15.5 and the trailing edges at 17.5. The prop definately had more out of the hole then it did out of the box. However it's still a little too much prop for the loaded 211 with the 330, it's probably the perfect prop for the boat with a ZR6 since it would help flatten out the ZR6's powercurve.

Performance numbers:
wide open throttle 4800rpm @45mph, 3600rpm @34mph, about 2400rpm @ 24mph (very close to 100rpm/mph across the band, as witnessed on the analog gauges, my wife kept getting the tach confused with the speedo). Good out of the hole until it was loaded, better then the stock 380 but still too slow for my liking. This would also be a good prop from a gas mileage standpoint if you didn't load the boat much. One other thing was that the boat made a bit more rumble with the prop, almost like there was a little blade turbulance above 34mph.

My next move is to take my 536 down to the prop shop and have them put a variable pitch of 15.5-16.5 on it. Plus their "non-slip" tips. Then I will have two good but slightly different props for use on my boat.

[TylerO]

Mikeski,

Your commented:

My Acme 380 (13.5x17.5) was repitched to a variable pattern with the leading edge of the blades at 15.5 and the trailing edges at 17.5. The prop definately had more out of the hole then it did out of the box. However it's still a little too much prop for the loaded 211 with the 330, it's probably the perfect prop for the boat with a ZR6 since it would help flatten out the ZR6's powercurve.

I have the SV211 Team with the ZR6 and the stock prop is (I believe) a 380. The prop is stamped 816 13.5X17.5V R1 1/8". Not sure what the 816 designates.

Anyway I just ordered a #644 as a back-up prop and am looking forward to additional hole shot. I will run numbers on both props and post them here. However, I'm curious what you meant by even out the power curve on the ZR6? I have found with ZR6 power curve really kicks in at @ 15mph now. What should I expect with the #644?

-Tyler

[Mikeski]

Tyler,

What I meant by "even out the power curve" is that the ZR6's extra power comes on above 2000+ rpm or so (only hear-say since I've never actually driven a boat with a ZR6, however based on the Denali 6.0 that I have driven it seems logical). So the variable pitched prop helps the lower end without giving up any top end speed. I feel this characteristic is a good match for the ZR6 power band making it feel as strong as a team prop down low and like a stock prop up top.

It appears that the stock ZR6 prop (Acme 816) is not the same as the Sport prop (Acme 380) used with the 330. They are the same diameter and pitch but the cup of the 816 is probably a little more aggressive. Looks to be the same is true between the 644 and 856.

You should expect very good performance with the 644 with higher rpm's on the top end and at cruising speeds.

Mike

[TylerO]

Mike,

Thanks for the info. I can agree with the hear-say as you really feel the power post 2000 RPM's. This is most evident with guest drivers in my boat who are used to the 330hp in other 211's and 210's. These drivers quickly learn they need to back off the throttle much sooner or they blow right by Wakeboarding speeds and Perfect Pass settings.

Do you think I will get any better low end with the 644 for the sacrifice of the higher RPM's at cruising speeds?