thisistank

3A's Rule! They are like the HP500's of the drive world Just put power to them and they keep going and going and going. My buddy has them on his 38 scarab with teague 800's has over 200 hours and no problem what so ever.

Tank

Mbam

Dueclaws, sorry you are correct. Some of the parts are still available, especially bearings and seals. And yes there are lots of used parts around, we have a few around here. It's just that you can't always find them when you need them. They are just getting harder and harder to support.

merlin540

how much power have you seen put through a big shaft #4 like the ones on my 32 skater will they hold 1000hp or not

Dueclaws

Merlin-
I'll bet BAM knows. I have no personal experience, but seem to remember that the 4's were rated similar to the 3s.

Bob Nordskog used to break them regularly behind his twin-turbo BBCFountain, but the boat was probably heavier than your Skater and Bob drove pretty aggressively. Plus he was on and off the throttles constantly.

Katdrvr told me he had a friend with a pair behind 900 (?) horsepower engines and the drives have never failed. He can add more info to this.

Maybe it "depends": weight of the boat, how you drive it, etc.

PS Have you run the Skater yet?

Mbam

Well, yes there are a number of factors. But I can tell you from personal experience that I had 850 HP @6200 carbureted engines in my old Cigarette with #4's, pretty reliable. Put blower motors in, 1000 HP @6000. The 4's did not last 1/2 hour. Boat weighs 12K. Went to 5's that had the early spiral gears and got another 100 hours or so before the upper gear set failed. Put in the new net forged uppers and went another 300 hours or so with no further trouble. All the drives are more sensitive to torque than RPM, so 1000 HP @5500 is going to be harder on the drive than 1000 hp @6000

The 3 and 4 have basically the same upper, but the 4 had the benefit of much beefier vertical shafts. A 4 with the older straight cut gears is actually pretty good.

shifter

750 ft lbs of torque @5500 is about the limit. I don't know who came up with that but it is what I read today on a military quote.
pat W

cougarman

Just wanted to thank everybody for your help and Knowledge.


Thanks

Cougarman

merlin540

thanks guys i will be testing soon i will post the out come soon.thanks again

BLOWN 1100

Maby i can shed some light on this. I ran 1100
hp, on #3'S for 7 yrs and broke once, still running them
but have changed to 1.22 gears with 17/26 props
and turn the engines 6100 rpm. The red 10 meter
Fountain
Loy

Dueclaws

That must be a screaming 10 Meter! How fast does it run?