Catmando

What I like about Pat's new dual prop drive is 1) shaft drive, 2) true surface drive and 3) twin props cancel torque steer. Lack of props might be an issue though, whereas he has plenty for the 6.

JJONES

Sidwayzzz

shifter

Props are not an issue.. I am working with Throttle Up. Matt and Julie make a great prop.

I deside what to try, talk to Matt and Julie, 2-3 weeks later voila testing and sending them back data on the runs.

pat W

ZXXX Donzi

Fair enough. Now I would like to know more about the Weisman and X drives.

I have heard of the Weisman and it looks pretty important. I would like to know what other performance boats have used it. It looks like a pretty stout product.

Catmando

Gary Smith(40Skater Predator) uses Weismann drives. Weismann has won World and National Championships in American and European racing.

shifter

Predator (old boat) 1990 40 Skater. Last year at Havasu 1 mile shootout standing start 163mph. 178mph on his best day wide open. We ran 3 years on that boat. When we did Gary's boat it had a wet sump 6 and we converted it to our dry-sump 6 drives. We dialed in the x dim. ran 161max. Switched it to the WMD and moved the engines back 5 inches to compensate for the cg change for the 400 lbs difference in the drives.

We are also running them on the platinum 41 ft Vee. Twin turbo 1400hp 572 cid Gentry motors. We just made the change and now it is time to test. Raced it at the Rum Run but took a couple bad waves and quit after injuring the throttleman.

There is a shot of a diesel military version that we did but I cannot show the boat. Same with a couple other different military boats. Note the big props.

I designed my drives to exceed that capabilities of the drives that are on the market. That is why there is a surfacing dual prop drive now.

pat W

CB-BLR

26redline,

Why so negative on the SCX drive? I know that the lowers eat speed, but an SC lower will bolt right up with no speed loss. John's boat was as fast or faster with a SCX upper, and a SC lower than it was before the upgrade. IMCO is claiming zero failures to date on the SCX.

I know of three people, including John, that have gone to a SCX upper with a SC lower.. all have reported posative results on speed, and an end to broken drives.

Do you have some additonal information that would make you not consider this option?

Chris

P.S. I think that adding tabs to the boat to help it get on plane would be a good idea
P.P.S. I am also pretty sure that with some machining by Max Machine, you could use their lower on an SCX upper

26 REDLINE

I was never negative about the SCX drive, just that it is rated for 900hp, I simply said that I might as well keep what I have, trust me the SCX is an option, and yes I would like my MMW to mate up to the SCX, my onlyconcers are how does the internal drive shower ofthe SCX get its water and would the MMW lower work, I don't know if the MMW upper shaft is an IMCO, I would think it is.

I am hoping that Pat and Steve will come up with something on the drive that was on Gary Smith's old Predator I really think that would be the chitssss

johnlomant

The scx shaft is different then the mmw. I already investigated that combo

CB-BLR

IMCO makes a conversion vertical shaft, that is installed into the lower unit of either a SC lower or a bravo lower. If MMW was willing to do some machining on their lower, it would probably work with their unit also.

The weakest link on all of these drives (IMCO SC, MMW, Teague, Bravo XR, etc.) has always been the upper gear set. They all use mercury gears. I believe that MMW treats the gears (cryo etc.), but the fact is, they just are not strong enough gears. MMW and IMCO make great upper cases to support the gear set, which helps, but in the end, you have a greatly supported set of mercury gears, which are just too small and weak for the power being supplied to them.

The XR upper gears are 3+ inches in diameter. The SCX upper gears are 5+ inches in diameter. The SCX has a built in drive shower and oil cooler. Your weak link now becomes the lower gears if using a standard size lower. IMCO is working on a re-design of the shape of the SCX lower in order to make it more efficient while using larger gears. The oil cooler in the SCX upper, should help the SC lower run cooler and extend lower gear life. Lower gear failure is not typically the issue with bravo style drives. It is the uppers that usually fail.

For some unknown reason, all three people I know that have switched to an SCX upper, with a SC lower, have gained about 1 mph.

On a different note; Eliminator is supposedly gaining 7-10 mph on their twin engine cats by switching from XR style drives to the Illmore Indy drives because of the greater efficiency of the Indy drives. Illmore is going to be realeasing 900 and 1100 horsepower supercharged engines, that they plan on mating to this drive. You might want to check with Elliminator and Illmore about using this drive in a single engine cat application.

If money was not an object, I would go with a Weismann or Arnesen drive. I would not go with a #6. The #6 is just too heavy and inefficient... especially on such a finely tuned boat. I Love the RPM cat! Steve did an awsome job in its design and construction.

Just my rambling thoughts.

Chris