SCX w/SCX lower
 

How fast has anybody run with these drives in V-bottom. I wonder if 120/125 mph is unrealistic.

My understanding of the SCX lower, is that it runs best when set up as a surfacing drive...like a #6.

I have a SC lower that I run at 3" below the keel.

I am looking forward to others chiming in.

Chris

I got my SCX/SCX drives. I'm going to try them in a surfacing configuration, I'll let everyone know what the result is. I will be 3.5" up from my deep bravo set up. To be efficient they must not be in the water is the consensus. Similar to the NXT. Then throwing prop blades needs to be remedied by having Herring make some props with thicker blades. It's gonna be a while before you hear about it though, it is cold here.

How about running #6 props with that lower as far as the blade slinging issue,my boat has a shaft height that is 1 inch above the bottom so in the future when I go to the scx drives I will go with the scx lowers just for that reason, I all ready threw a blade with my herring 5 blades, they scare me ! and I see my maximus prop has a crack in it know.

Sonny said that he had Hering make some special props thicker just for this. 6 props would take care of it.

I have heard that you want to run the SCX lower in surfacing mode (like a NXT or #6) and use #6 or Maximus props. I am sure Ben at Hering can get you dialed in...he is a great guy!

Chris

I don't really want to run cleavers or be throwing blades by surfacing round ear props. Boat is getting close to being done, I have SCX lowers and think that maybe I should have gone with SC lowers.

This really interestes me. I have been torn between scx upper and lower or the arneson bravo conversion. I hate my broke SC junk! I like the rooster of the arneson and the speed. But never thought about running a SCX like a surface drive. I might just try it this summer. My drives are already raised up due to my stand off boxes placement and adjustment (stelling). My SC are standard length lowers. So when I order the SCX the shorty might work perfect. Am I on the right track? Thanks

Does anyboby run SCX lower with a V-bottom?

I have a friend with twins in a v bottom with SCX lowers he is running as fast if not faster than the XR's he replaced. Went from XR to SCX which is -2". Only runs 96-97mph though.

What boat and combination do you have Dave?

Hallett 335, w/1100's and IMCO boxes.

I have run 104MPH but did not like the handling or the loss off my top end. I currently run a SCX upper w/SC lower. Ran it in a surfacing mode did not like it at all. The combination might work good on a heavy V-Bottom but not if top speed is the intended goal.


Comment:

Well I would respectfully disagree with the above conclusion.

XR vs. full SCX same height the XR will be faster anything else is misleading. I have run Full SC versus a SCX/SC lower in the same day and it was no comparison...full IMCO SC blows the SCX out of the water period. Go one step further full SCX upper and lower versus full SC drive and you would have a HUGE difference on the top end.

Carryon!

KAP

P.S. I currently run a SCX upper with a SC lower. Why because with the HP I am pushing I'm willing to sacrifice a little on the top end for longevity on the costly upper.

Thanks for the good info.

Why did you not like the drive in "surfacing mode"?

I personally have seen the boat run that Mr gadgets is talking about. Not only is what he is saying true, but the owner drives his boat like a performance boat should. I have never seen it down due to drive issues with the scx (like the xrs). The owner is very happy with the scx upper and lower combo. Just as fast and reliable for over 600 hours so far!!!

I am done breaking my SC junk! In search of something better now.

Is anyone else running scx upper and lower in surfacing mode?

I really think that IMCO could probably help it's customers out by having demo units. It would be nice to try different combinations so you don't either have to make a quess or buy a bunch of things that aren't going to work. They could charge you for this and give you 2 weeks to try it. I realize that this could be abused, but I think it would pay out for them in the long run.
The only person I found that used the SCX lower surfacing was Sonny on a 36 Spectre cat. However, the drives that I bought from Mark Terry(Dock Holiday)were on a 36 Outlaw. Read his 90 page dissertation and it will show you the rigging. IMCO boxes. Contact him and he should have some good information for you.
.

"Well I would respectfully disagree with the above conclusion."

Sorry Kap, but this is not a conclusion, it is fact. His boat likes the SCX lowers.

I agree it didnt work for your boat. But my friends boat did like it. An we are not talking apples to apples with the two boats.

I dont like to pass on conclusions. I repeat experiences I have seen or heard about. I have known my friend for 20yrs, when he says something about his boat, I believe him.

Just my .02...

kyelimeagle, what gears are in those scx drives, i pmed him right away when they popped up for sale but he didnot get my mesages, but I got the scx helmets from him so far,and working my way towards the drives.

Doc said they are 1.50s. I was ready to drive 30 hrs round trip to get them. But he went w KyElim cause he was closer.

Well Im not dissapointed now I need the 1 . 34 gears, I will just have to keep my eyes open .

Comment:
Well a lot of stuff to reply on--- rather than cut and paste. I will simply make some comments.

Mr. Gadgets, if you read my post it says same height XR versus full SCX the XR will be faster...hands down. No comment on reliability just which one goes faster. The XR will be faster I don't care what hull you put it on versus the full SCX.

Talk to Gary Teague at GT Performance about his Donzi and he will tell you the full SCX is slower and his boat has the motors and he can drive. I hate to drop names but all this bull**** just confuses the average person who simply wants a good drive that is not going to break or open his/her wallet everytime they go out.

As for my experiences and facts they are first hand not my buddies or friends. Call IMCO they will tell you the full SCX is slower than a full SC. What you get with the SCX... is reliability when running big HP or a combination of big HP on a heavy boat. The reliability comes at a price on the top end if anyone disputes this they are lying or just plain ignorant.

Don't misread what I wrote the SCX is a strong drive and I like it on heavy V-Bottoms but the purchaser needs to know they will lose HP/top end when they put them on. It is not argumentative but rather common knowledge.

There is one person on here who is going to try the full SCX on a cat to see how it does. He has a high X-dimension and he will end up running cleavers on a surfacing SCX set-up. I am real curious to see how it comes out.

If I were to guess on that set-up I would guess that it will work but at real high speed 100MPH+ the boat will not have the control or handling. No rush to judgment rather I will wait and see what the results are if the owner does post them up.

KAP

P.S. Thread related the author here just needs to be aware of the possible outcomes before they go spending a ton of money and then find out they are not happy with the top end performance of the conversion. Wish I had someone doing the research for me... rather all my data was paid for by me [and this does not include time and effort] by the Kappy boating fund:drink:.

575 cat they are 1.5's, I'm going to need 1.24. I'm going to test them with the 1.5's and see if it's going to work. If it does, I'll swap the gears out. If not, I'll sell the lowers and go with the SC lower. I'm not going to swap them unless there is some evidence I can get the combo to work.

let me know if you are going to sell them, I was going to steer to the number 6 props with the scx lowers but you are right , I was talking to jeff at hering and they will cast up thicker blade bravo props at the same cost as standard .My settup is full surfaceing of the props and I dont want to change that , thanks dean

I am confused. How do you make them Surfaceing vs standard? Shorties?

very high x and shaft height w 2 inch shortys, right now my shaft height is about 1 inch above the bottom w 2 inch short sportmasters and also 18 inch crank centers, socalled full surfacing props which the bravos do not like or will last !

Everyone is talking 'Surfacing" and no one wants to loose speed or spend the money only to continue the maintenance cycle that they currently have.

Why not just fix the problem once and for all and go Arnesons?

Rik...I love your drives...and think they are great.

But what is solution for the guy with a 1200hp single engined cat or v-bottom?

I have heard that there are quite a few people that have tried the single engined Arneson route...that could not get the boat to work very well with your drive.

I am sure there are exceptions...

What is your recommendation.

Chris

P.S. My fantasy boat would be a 30 or 32 skater with a pair of Arneson's and a pair of naturally aspirated 598's spinning about 6500 rpm.

Rik,
Arnesons may be the perfect solution for me. But the cost would be 46K plus install @ 5-7K and fiberglass work? With the SCX, I should have some margin of durability, not close to your drives. With the SCX, I have a safety net, if I can't get the combo right, I can go back to what I had easily.
If I sell the boat, or have to sell the boat, it would be money down the drain...... no one is going to get more than the average price of their hulls today. That drive system would be over 50 percent of the surveyed value of my boat. That would not be a good financial decision, not that any of these boats are a good decision. I showed the drives to my wife. She said that looks dangerous to swim. We boat with our kids and our tunnel tab is the best diving board.
When and if I build a new boat, I will probably use them if on a hull that they have been successful on. I have been able to buy some like new used drives and will have 1/3 of the cost of Arnesons doing this. You've got a great product and I think probably priced appropriately in this market but too much of a financial risk to take for me. You ought to get on a poker run circuit, I have never seen the arnesons in operation.

What's the largest diameter SSM prop you can run
on a SCX lower, set up with a big shaft ?

Being that it's already 2" shorter, I cant imagine you
can run anything too large.

I believe it was 16 inch as it was braught a while back.

Just measured the distance from center of propshaft to cavitation plate on the SCX lower is 8.5".

Dick

is that a -2 lower ?

-2 lower is only option

Yes.. that is the -2" SCX lower. Without any spacers.

Hey KY not to get off track but how are eddies engines work out , hopefully I will get mine back in a few weeks. thanks

Engines working out well. They run awesome. Only had 2 problems one was with whipple pulley bolts breaking and with a brand new starter going bad. Most all bugs are out. Post some photos of your engines. Here's a photo of the SCX lower with a 15 5/8(large) diameter Maximus.

I dont have any pics to get really excited about, he has the short blocks together and waiting on pans, whipple kits, heads to be installed ,so a little ways to go yet, I will post some when we get some better ones. So with the scx lowers you could almost get some 17 inch #6 props on there ? what props are you going to spin now with the 1.5 gears ? Also it looks like in the first pic the hub does not match up to the gearcase housing to well.

The hubs are tight so I didn't put them all the way on so I wouldn't have to tap them off. The pitch is 34. The 6 shaft lowers should be able to handle 17" props. Eddie takes his time on the short blocks, the rest comes together faster.

cool , he probably thinks im getting impatient. now back to the drives, it would be nice to find some # 6 props that I wouldnt have to cut down so far that I couldnt resell if they didnt work out.

Comment:

That is correct 16inch cleaver is the largest diameter you can run on the SCX -2 with no spacer. This will give you enough gap for blade flex but just barely.

KAP

P.S. KyelimEagle can we see pictures of the transom of your boat. When do you think you will run it...if so take some video.

Kap, it will be May per my insurance lay up. I am trying to get all the things I'll need to test. I've got the 2 sets of lowers and 3 sets of spacers. I need to find some more props to test. Here's a rear shot of the boat.

Thanks for the photos.

As for propellers any HP level will work. In fact Super Cat Lite props are the best in my opinion. Your boat is light and don't worry to much about the HP rating of the propeller. You are not going to hurt the propellers unless your making OSS type turns and flying the boat which I doubt you will be doing.

The SC Lite props or lighter really give you the top end:drink:.

KAP