SCX upper - SC lower?
 

I have an IMCO SC now, and have upgraded my motor to 750hp/ 750 lbs of torque.

I have heard that the SCX only comes as a 2" shortie at this time, and that the drive is somewhat slower than the SC due to its bigger rotating assembly, and larger foot on the lower.

I was also informed that my SC standard length lower would bolt onto a SCX upper. This would give me the benefit of the stronger upper gear set, with the reduced drag of the SC lower.

The weak link would be the lower gear set, but it is my understanding that it is the uppers that usually fail.

Any thoughts on this all??
Have you heard of anyone doing this??

Chris

Chris,
that has been done before, I believe. The SCX is shorter, and you can get spacers. And you are correct, the lower gears would be the weak link, but at 750hp it wouldn't be that weak of a link.
I did speak to one guy that used Merc Sportmaster lowers on an SCX upper.. He may chime in??

Dick

Dick,

After extensive testing, I use a 1" spacer on my standard length, SC lower, for my Nordic Heat. I was told that the biggest SCX spacer is 2" which would put it as deep as my SC lower, without a spacer.

I am just thinking about options for my outdrive, in case it goes boom with my whipple upgrade.

Chris

Well the missing 2" on the SCX is in the lower unit. The SCX is -2" shorter. So if you put a standard lower on it, it should end up at stock length. A 1" spacer would put you at the right height.. to go like a bat out of H*ll.. :)

Dick,

Yup, that was my thought on the length.

How much Hp and Torque do you think the SC lower will take before failure?

And do you think that the SCX upper is going to slow me down some by eating horsepower?

Chris

I know a number of guys running 1000hp on the sc.They tend to have more problems with the upper. I don't think you would have a problem with a 600sci.


Darrell.

Darrell,

My 600sci has a few Whipple goodies on it and produces around 750 hp, which has propelled my 28ft Nordic Heat, open bow, to a best of 91.1 mph.

Prop slip with the current Hering 5 blade bravo prop is at aproximately 6%, hence the concern for my outdrive.

Hering 27 - 91.1 mph at 5700 rpm
Bravo 30 - 90.4 mph at 5800 rpm

Chris

750 is still within the norm for a LOT of boats running the sc. Most of the damage I see from friends and such, are with the uppers. And these are on boats with quite a bit of hp. Lowers seem to be very solid.


Darrell.