FS: Acme 668 (12.5x15.5) propeller

For sale: rebuilt Acme 668 propeller. This is a 12.5x15.5 (.150 cup) 4-blade. It is the "extra cup" version of the 422, which came stock on the 6.0L direct drives in the 00's.

This came to me in a group of props, I just don't have a need for it. I tried it on the Crush briefly and it ran fine. Perhaps incrementally less smooth than a new prop, as can happen with some rebuilds, but it's only something you'd notice if you ran it back to back with another (new) acme and were looking for subtle differences. It would still make a fine upgrade over a hand finished prop or a great spare.

Asking $150 + shipping

Email: TRBenj@gmail.com



I can answer most application specific questions with some intelligence- feel free to ask!

Ha, I said *most*!

I know you're joking but it might not be far off for what I assume would be a ~400hp, 5k rpm set up in that tug.

quinner wrote: How about an Excalibur powered 206 vs a 422??

If you were specifically trying to lower rpm at skiing or cruising speeds, the 668 would do it.

For all around use, especially top end speed, the 422 is going to be hard to beat. The excal will be happiest if you can prop it to turn 5000ish. On a 206, I suspect you're probably closer to 4900... So a prop with less pitch or cup to get the revs slightly higher would be a better way to go if you were looking to make a change with that in mind.

TRBenj wrote: Ha, I said *most*! I know you're joking but it might not be far off for what I assume would be a ~400hp, 5k rpm set up in that tug.

Actually not joking so much, bills boat had a 13x17 on it, so did my wildcat with the 290hp 426. This might be in the right area considering I am close to the hull and wont be able to get a bigger 3 blade in there without spending money.

I was/am still hunting for a 422 for my 95 Sport with a GT-40.
Would that be a good alternative for us (mainly wakeboarding/skating, slalom but now also some footing)?
If you think it's gona be better than my old 3 blade, then we got a deal.

PM sent

New wheel is on the boat.
Only ran it 2 hrs last weekend with the family and no time to meassure a lot but here is the butt gauge indicator:
smoother pull when skiing and nice acceleration when modearet with the throttle
Lower top end speed (expexted)
And it feels like some cavitation when going all out from a dead stop

Tim, it is better than the old wheel
Have not yet looked at max rom etc
I'll see what GPS speed I'll get at 4200 rpm's which the tag on the GT-40 sais is max sustained WOT is (4800 brief)

The "cavitation" was geared towards the feeling that at WOT from standstill it seems to take a while to catch and spinn somwhat

Toertel wrote: Tim, it is better than the old wheel Have not yet looked at max rom etc I'll see what GPS speed I'll get at 4200 rpm's which the tag on the GT-40 sais is max sustained WOT is (4800 brief) The "cavitation" was geared towards the feeling that at WOT from standstill it seems to take a while to catch and spinn somwhat

Man, 4200 at WOT is lugging it pretty hard, I'm pretty sure I was closer to 4700-4800 with the 422. I just went the other direction with an 1868 (12.5x14.25) and I get 47.5 at 5530 in my '94 Sport. I don't plan on running it too often wound up tight, just did it to see what kind of speed I lost off the stock 14x16 OJ 3 blade and 422. No cavitation out of the hole, the RPMs just wing up to 3500 and it's gone.

4200 is what it says in the book, not what his HO 351w is capable of pulling the 668. I'm betting it's at least 4500. That would be a heck of a lot closer to the 4800 power peak of the engine than 5500rpm! I tried the 1868 and those revs are just way too high for a lightly loaded 19'6" boat, IMHO. A heavily loaded sport is another story.

Let us know what you find Sebastian!

halfnelly wrote: Man, 4200 at WOT is lugging it pretty hard, I'm pretty sure I was closer to 4700-4800 with the 422. I just went the other direction with an 1868 (12.5x14.25) and I get 47.5 at 5530 in my '94 Sport. I don't plan on running it too often wound up tight, just did it to see what kind of speed I lost off the stock 14x16 OJ 3 blade and 422. No cavitation out of the hole, the RPMs just wing up to 3500 and it's gone.

I find it hard to believe those numbers but pictures don't lie or do I call photoshopped

I can spin the 422 on my 98 Sport 5100rpm but get no where near that 47.5mph.

You must have a fast hull. I think the small changes to the 98 Sport hull did slow it down. I have suspected this because the reference section has top speed figures on the Sport higher than the Ski of the same year before 98.

Sport Hull Changes

halfnelly wrote: Now I'm curious so I might slap the other props back on and get some more data. I'll post the results in another thread to stop hijacking this one

Add your info to this thread Sport props and Speed

Hose at the trans cooler split was not tight and is kinda old
Tightend it and ran fine. Will change hoses in the winter

Changed cap, rotor, wires, plugs and coil this Friday, took the FAE off and she ran 45.5mph with 3 adults, a child and loaded with gear.
Same night I drove back home alone and at 46.6mph on the gps ran out of lake.
Need to find some glass and see what she can do