kap328

Well DonRoc:

Give it up what does that boat run for top speed.

I know those Procharger motors put out some juice and 572 cubes and getting pistons coated are we running some high compression.

Well once you get a cat it is real hard to go back to a v-bottom unless it has rooms and flat screen tv's watching the game drink in hand.

I run 118++MPH in a deckboat and that always gives me a rush I can hit that speed consistently. I just need to get this drive set-up right and I'm gonna leave it alone for good.

KAP

DonRoc

I cant give it up just yet.. Need to make some changes and more prop testing.
I was running 15psi boost with 8.1 to 1 compression. so felt the tops need a additional protective layer. I am making a cam change while its out also. I want it perfect so am doing a lot of R&D. motor has been out 3 times in less that 10 hours of testing for subtle changes. I can say 110 is not a problem.and that was the first test prop I tried. Full tank 90 gallons fuel...about 700 rpms below where I want. The SCX with the -3 SC lower limits my props and they need to be custom made which kills me when testing props. I made a custom 1/2" spacer and rounded up a bunch of props for our next run. when I get close I can get the prop cut some remove the spacer and tune it.
I have a ton of 4 blade and hope Brett (BBLade) can get me some 5 blade test props. with the old engine the best props were a stock 30 B1, and a 30 labbed Maxuimus. the Maximus was 300 rpm less and about .5 mph faster, but ran the flattest.

DonRoc

Anyone know of a coupler for the SCX/SC beside stock length? IMCO does not make them. we made one but would like a factory one. 1/2" longer for the spacer

CB-BLR

Put a SCX vertical shaft into your SC lower, and you can then use all the SCX couplers.

Chris

J.P.

CB-BLR

Where exactly is the plug on the Imco SC lower. I have a Bravo 1XR upper and was just wondering where the plug is, not that I can use it for cooling my drive. At least I don't think I can. But may one day have the SCX upper.
Joel

DonRoc

I know that is an option. But just was hoping someone made a coupler. You would think with all the guys using the SCX/SC they would make a coupler for some spacers.

CB-BLR

The SC/SCX couplers were originally intended to be B3/SCX couplers... ie mating the B3 lower to a SCX upper since lots and lots of cruisers use the B3 lower, and continue to shred the XR upper due to the duo-prop design of the B3. The SCX is a perfect answer to the heavy cruiser/B3 problem.

The conversion couplers are expensive to make due to the different spline configurations, and not enough people are doing spacer testing to justify the different coupler lengths.

Just do the SCX lower shaft, and do all the spacer testing your heart desires.... I know that is what I had to do.

Chris

CB-BLR

The further most forward hole on the mating surface between the upper and the lower is used as the speedo tube in a XR, and as the integrated drive cooler feed for a SC/SCX. This hole should be plugged when using a SC lower with a XR or X upper, and open when using a SC or SCX upper. It is threaded in the SC lower as it comes from IMCO.

Chris

J.P.

CB-BLR

Thank you for clarifying.

DonRoc

Its just temporary for me until I get close on prop size then I will remove the spacer and get a custom prop. With the scx, sc-3 I had to get custom props and that was getting expensive, wasteful and slow turn around for testing. So I put a 1/2" spacer so I can use stock Diameter props to test with. I made a custom coupler for testing.
I may have some props for sale if anyone has a standard upper with a -3 lower these will work. I need to finish testing to see what I am keeping first.