SCX Upper gear setup
 

Anyone have any experience setting up SCX upper gear lash? I'm curious what numbers you may have seen. I'm going through one now that had a lower shed some metal. The upper is in great shape but I'm still doing a tear down to flush and check where the lash was originally set. This is a low hour drive so I don't think it would have changed much.

Thanks,
Jon

What caused the failure? what boat and HP?

Other then IMCO, anyone know where to find used SCX's??

The reason I am asking is next year I will be in the market for an SCX-4 when I put the M4 Procharger on my engine.

Why not a PSI 206b?:drink:

Believe me I sure like the looks of one of those. The Procharger's are UGGLY. BUT with the M4 I can get the same HP with only running 93 octane.

What can the M4 do the PSI wont? How much power are you trying to make on 93?

PSI looks like a sbc sitting on top of a bbc. Love em

I will make over 1400 HP on 93 octane with the M4 on my 598 CI BBC.

Injected?

At this point the plan is to have a blow through carb. BUT it just might end up injected because I would use a front mono throttle body.

I absolutely loved my fuel injected prochargers! I love all forms of forced induction when done correctly though.

The question is will your engines actually support 1400hp? How "use able" will this setup be especially with a blow thru carb?

Not singling out any one person but making reliable marine power is not as easy as OSO thinks. Its one thing to make a dyno number another to have it last in offshore conditions for 100s of hours.

SCX and SCX-4 are only rated for about 800hp, yes they do OK behind more power but.....

And the SCX-4 swinging an offshore style clever prop is no walk in the park to dial in, plus dont forget to upgrade helmet, gimbal ring, reservoir, and adding an extension box.

Already have the extension box ( going on this spring) and the boat came with an HP gimbal assembly and oversize reservoir. And dialing in a boat is what I have done many times. Before I even thought of adding HP.
Have you heard of DAVE WESSELDYKE - He is the person doing all of the machine work ( I will assemble the engine - Not my first high HP engine or my first solid roller ) I am using all of the parts to handle the power I plan on producing.
This is all going in a light boat that will run at high RPM with a very high X dimension so there is NO chance of hammering on them out of the hole. My X last year was 1 inch above the lowest part of the hull. With the new neutral extension box I am going up another inch and may even go a little higher. Last year I ran a -3 IMCO shorty ( 11% slip from 4000 up to 6000 RPM) but have a -2 as a spare if needed. SO IF I go lets say to 2 1/2 inches above and it is too high I can just install the -2. I adjusted the drive for more negative trim in order to get on plane. ( It didn't begin to get on plane without this mod.) adding the box should make the increased negative trim work even better and with the higher X I should be able to trim the drive in more for more efficiency. Last year I was playing with props. Had the 28 pitch Bravo one off of the Scarab and was getting on plane without any real problem ( -3 ) Then chopped 1/2 inch off of the flare on the back of the prop to try to settle the transom at top speed. ( it worked great but was a SOB to get on plane.) The boat loved not having the bell on the prop acting like a ski. I also sealed the cavitation plate to the drive and sealed the exhaust passage through the drive to stop air getting into the inside of the prop while getting on plane. I figure the water sitting inside the upper drive housing wouldn't hurt the cooling either.

Dart big M tall deck block, Crower crank, Lunati rods and JE pistons. AFR 355 CNC heads with upgraded valves and springs ), Bob Madera solid roller cam and his recommended lifters with internal oiling. 14 Qt oil pan, Jessel belt drive and Jessel pro shaft rockers. I am thinking at this time to use a Holley HP EFI as the ignition control and latter adding the fuel side.

Kick ass engine.

Thanks

Not even close to the info I was looking for guys...

No problem, glad we could help you out. :rolleyes::Whatever:

Not the help I was looking for. :hijack:

Again, no need to thank us.:blahblah::blahblah:

909-592-6162


https://www.imcomarine.com/cal_store/

The upper pinion gear back lash should be .006" to .008"
Send me your email and I'll send you more spec's on setting up the upper

What brand oil & what weight oil do you use?

Thanks Ocean! Exactly the kind of response I was hoping for. I appreciate it.
I'll send you a PM.

Good thing we kept the thread at the top for you so it got noticed!

No, more like... I'm lucky Ocean weeded thru all your BS to politely offer some helpful info.

Who lit the fuse on your tampon?:bananalove::gfight:

I asked what boat and HP was this drive installed on???

Thanks for answering everyone else's questions given to you

You've been a tremendous help to the forum! :Score-101010: