SCX or BMAX
 

I've been hearing more and more failure stories of scx drives. I also know John at the bravo shop is constantly striving to improve the bmax drive, but there's limited info on them

if you had to buy one today what and why. Cost is pretty similar for both brand new units with the bmax being about 1k cheaper per upper and no helmet or resivoir swap.

I plan to run one of them with standard SC lowers

Whichever one you go with, make sure to run the bravo shop neo oil at the very least. We also run this oil in our superchargers.

Another vote for the Neo oil. I run 800ft lbs thru my XR's and I know it works as it comes out the same color as it goes in. I have burned up all of the "other brands".

Well if your going to use the Bmax oil you mite as well run a B,max drive :)

Broke SCX's?? Guess I missed that. I have Abused mine NO issues

Yeah some SCX have broken
Some are just wearing out after hundreds of hours
Some are greatly over powered
Some have the much weaker SC lower
and don't forget the SCX-4 and SCX running HUGE #6 props

Still wouldn't want a Bmax with JUNK XR lower gears.................

I'd change out the reservoir for sure with the b max. Stock bravo holds 2.5 quarts, bmax almost doubles it holding a gallon.

Also the old bmax you needed to drain riughly half the oil to take it off the boat. Don't know if new ones are that way or how the scx is but that sucked, buy stock in your oil company.

I love my SCX drives. I run 700+ HP and Torque through them and in 7 years only had one cone clutch stick. Before installing them I popped 3 Xr drives in 2 years.
I have heard some issues with the SCX-4 when running too high and with 1000 hp+ trying to be run through them but that's really it. Like others have said, usually just an age / time to rebuild issue.

I am w you Tom I run 700+ and after 4 summers of Hard boating and lots of Air-- I sent them back to Imco and Fred himself talked me thru two options-
1- rotate sides and run for 2 or 3 more yrs w little worry
2- Have them replace some things since they are already there- I picked door 2. I think $1500.00 or so shipped back to me. Great customer service Thanks Fred.
Now I will rotate each year and probably be good for quite some time.

I was spending Several thousand a yr fixing XR's. I had two sets. One on boat One in Shop. SUCKED.
Lost some speed YES- Boating all year YES!! And I will be again as soon as my Motors are back together.:flag:

Very satisfied customer.

4 years on my scx4,800+hp no problems.Drive works real well on my application.

2008-2016 B-max
 

I have had fantastic results with my B-max's, 825 dyno HP and not one failure.
I did have to back bore the lower cases as the machine work Dean had at the time was crude to say the least.
From what Bender has told me the new B-Max machine work John dose is very good.
I finally had Ron Bender go through the drives in 2016 two sets of gears in the lower and that was all it required, upper gears were perfect.
and that's on plain old mercury hi per oil (green stuff not the new version)

My close friend has a cat with SCX drives with the SCX lower no failures, but he's not a very aggressive individual and is quite comfortable at 70-80mph mark
That's not really a fair assessment of the drives abilities.

Soinc
 

Soinc could you clear your private message box ? Thanks John

way to reach me
 

MASOMEN
I'm no longer a paying member, There fore I have no PM box.

If you need to reach me PM
phil_p99 he has my number
give me a text

Sonic you don't need to pay to have PMs. It's likely just full. You only get like 10 as a non paying member. Just a heads up.

I.C.U thanks Ill fix that.

FWIW I have one of the earlier model Bmax drives with an Imco lower. Previous owner had 930 HP and loved the throttles. I got the boat and had about 800 ish HP. Now the boat has 911HP. All this over the coarse of about 5 years and no drive trouble I run what ever it is that the Bravo shop told me it was....mercury HP 90w I think. Trouble free tho

BTW, the 10 includes Sent and Received PM's

We have an IMCO SCX upper/SC lower with two seasons on it (26 cat/850SC power). At the end of the second season we developed a stress fracture in the SC lower case. Performance Boat Center replaced the SC lower and installed a DriveGuardian this fall. The SCX upper looked great when PBC went through the drive. We keep a 34 pitch non-labbed B1 prop on the boat and pull skiers, tubers and triple digits on any given weekend. Our use of the boat leans towards the hard side. IMCO suggested going through the SC lower after every season with our style of boating. I think both the BMAX and SCX are good options but stress something enough and it's going to wear/break, no way around it.

Griff
Thanks you

That's awesome! I too pull skiiers and tubes, and can make 80+ mph blasts when the kids aren't onboard. Even more impressive with an aggressively set-up cat like yours!

I had nothing but problems with mine for 3 years, absolute nightmare. Took 3 years to tell me that the IMCO lower water passage doesn't mate up perfectly with the Bmax. A Merc Lower, or Bmax lower will. I fought water pressure issues, I wish I would have just been told when I purchased the Bmax that the imco wasn't a great option. Would have saved me thousands. I still believe in the drive, just didn't work for my set up. My Bmax upper is for sale for 2500, has like 50 hours on it and 20K into it. Needs to be gone thru. Good luck-

I plan to run one of them with standard SC lowers[/QUOTE]

John made me aware of the water issues right away . I am now selling my -0 imco lowers

If you compare two seasons on the SC lower vs. the new SC lower you would assume it has it's limitations. We'll see how the DriveGuardian contributes.

I thought you could run the Imco SC you just had to do machine work for the water passage to line up and the shaft change to fit the Bmax upper. Maybe I'm wrong but John at he Bravo shop said you could run it.

I called and asked them about it..

The Bmax uses the speedometer water pressure passage for it's cooling water. Both the Merc lower & the Bmax lower have separate inlets and passages for the engine cooling or speedometer..

The Imco lower doesn't have a separate speedometer inlet hole, it's combined with the water pickup. So, the drive cooling water and the engine cooling water flow fight each other, so you could either not have enough engine cooling or not enough drive cooling depending on your seawater pump setup.

There are alot if people out there running sc lowers without issues though.. one of my good friends included

I know of two BMAX's that would be available. One in pieces and one making pieces. Owner bought them new 5 years ago from Bravo Shop. Put on 46BT with 525's. He had so many failures he purchased two new bravo XR's from PBC this year.

Wllks what kind of failures are we talking about here?

Any time you're trying to push a 2 bedroom condo through the water something has to give...........:santa:

Have had my boat for 3 yrs & beat on it w/ no issues besides losing reverse towards the end of the past 2 seasons. Separate drive each year. Found it was more on the shop that went thru them just before I bought the boat, than an issue with the drive.. They are finicky to be put back together correctly. We don't have huge water at Cumberland but does get decently rough on the big weekends. 850's & Imco -2's mated to the uppers. Pulled them apart clean, new bearings & good to go. Mine are an older pair that have had some updates to them. Hopefully Back4more see's this post, he had lots of years in my boat with them & did a lot of the work to make them pretty good.

A variety of issues on both drives over the 5 years. Boat is at LOTO and was always services by Bravo Shop up till owner had enough and went to PBC. Owner said BShop always pointed the failures toward something else. the upper gear set never failed but ended up needing replaced due to other metal in drive

Is the BMAX drive using the larger Volvo Penta DPH upper gear set? I know the uppers are heli cut. The Volvo Penta DPH is used on their high torque Diesel engines. It would make sense on where they get the gear set. The DPH is a cone clutch gear set much like merc bravo.
http://bravoshop.net/index.php?main_...oducts_id=1494

https://m.ebay.com/itm/VOLVO-PENTA-F...-/351769857299

No way. Look at the difference in the top housing width. The dph is like a b1. The bmax has a 5.5" ring gear. It's huge!

I have seen Bmax gears close up and looking at these two they look Very similar. Nothing wrong with it. Volvo D6-400 is running 700 ft lb of torque through them with warranty and from my research have been reliable. VP recommends inspection/replacement at 1500 hrs. Merc is running 575 ft lb with XR gear set behind 370 hp diesel

Can not speak currently for Volvo but their gears were made / manu / process in Sweden in the past. Their outdrives are tough - we have seen and worked on the old DP that all the oil has leaked out and still held up over the test of time. The older Volvo drives, not the best looking but they worked and were very durable.

The DPX was another darn good drive made by them. Expense and lack of props was the negative.

SCX vs BMax Questions that come to mind:
- Resale value of our boat with them installed, is it a positive vs XRs? Are buyers worried about replacement BMax and IMCO parts?
- Behind 770hp/side is one a better choice than the other, will the "lesser" drive of the 2 be reliable with that power?
- Running heavier oil help gear life?
- BMax uses the standard XR helmet? If so any failures because of that?
- IMCO reservoir change, is it best do with a BMax also?

SCX for sure , had standard & SCX-4,s , 980 + hp a side . Dont bank on resale now days , only for your own piece of mind . I would be worried if your still running bravo,s . SCX has to use a larger [ IMCO SCX only ] helmet & gimble ring or it will not fit .

Bmax do use a hp helmet/transom assembly. And it comes with a large reservoir.

Mine have been flawless so far so shifting issue no water intrusion no metal. 36ft eliminator cat