B1's on ITS Boxes
 

I bought some near new ITS boxes for my Formula and after the fact realize that merc doesn't make a long input shaft for the B1, only the X series drives. I have a practically new set of B1 Swept back uppers that I planned on using but at this point I don't see how that is going to happen. Does anyone have any suggestions other than selling the B1 uppers and replacing them with X uppers.

I would think there would be a way to change the flange or the u joint to be able to run the long shaft on your upper.

The XR input shafts use a larger u-joint and I believe the gear end shaft diameter is bigger. The only thing I can think of, is to turn down the short end of the XR input shaft so the B1 gears would fit on the x shaft. You can do this with XR propshafts (so you can run standard Bravo gears) but I don't know if you can do this with the gear end input shaft.

It seems to be a rather complicated project. In addition to the above, you also can't just install an X input shaft because the retainer ring, as I understand it, is larger than a B1 retainer ring. You also can install the B1 ring on an X shaft because the yoke is too large and the spanner wrench won't fit over it. My head is hurting with all of these small yet road blocking differences.

The 336 formula for sale at shogren has bravos on imco extension boxes. How do they run those?

Imco makes their own shaft, but its longer. The ITS boxes are only 7" whereas the Imco boxes are 12". The shafts are not interchangeable.

So maybe shortening an imco shaft would be the easiest way to custom make a part?

Thats a pretty expensive option. IMCO wants over $700 for just 1 shaft, then the machine work to make it fit.

It's a boat...nothing is cheap lol. Prolly cheaper than the xr upper upgrade but you would also get strength of the xr too that way.

There are joints out there that are 2x2. (2 different sizes per plane)

You can do it by using an X gear set and the ITS u joint shaft.
Imco makes a retainer that will let you do that on the standard upper housing.

I did this for my Blackhawk but it was a few years ago. Yes I remember the spanner wrench problem. We cut our spanner wrench in half, then put 2 "splice" plates on it with some screws to hold it together. I'll try to remember to post a photo.

Class6- I was wondering about that. This would be the easiest way. Otherwise I may have to do what MBAM suggested and swap out the gears.

I've got several B1 swept backs- I just tore into one and it appears one of the three has been upgraded to the X gears and yoke. The center socket has these part number stamped in it 3GKN-0-04. Can anyone verify that this is an X series input shaft? Both have greaseless u-joints and the one listed is different from the two unmodified b1's- as in bigger.

Mercury makes the ITS input shaft for both size universals. The newer, larger style are the current model but they still offer the older smaller universal style. I know this because I have the smaller size universals on my drive. I actually bought my ITS shaft from another OSO member about a year ago.

777Offshore- Thanks for the info- Shogren had a big sale that started last night and they had a great deal on a complete ITS shaft and yoke, so I bought it. I also have 4 Sweptback B1 drives that I've picked up over the winter. 2 I knew were standard B1's, 1 I assumed was a B1 and the other is a B1x. The one I assumed was a B1 turned out to be a B1 case that was upgraded to X gears and shafts. So it looks like I'm going to be all set as far as getting this set up.

How is your project coming along?

It's coming along, ended up having to replace stingers and bulkheads do to rot before anything else. Almost finished and ready to cut X in about 2 weeks then start rigging and testing.

I wasn't planning on pulling my engines and re-rigging this year, but I say that every year. At least this ITS system looks pretty simple to install.

.
You could try and get Latham to sell you the shaft from 7" ext box kit. http://www.lathammarine.com/extensio.../kexb-7979.htm

I'm all set- 1 of the 3 Bravo uppers I have, has been converted to X gears and the large input shaft. And I just bought another X upper so I'm all set to use factory parts. If anyone needs a pair of low hour (25 hours) Sweptback Bravo 1 uppers let me know. One I know for sure I don't need them, I'll be selling them.

Have you given any thought to how the 7inch box is going to affect your drive height? The further back, the deeper the drives are, due to the water rising as it comes off the transom. Are you going to run sportmaster lowers or just your standard bravos? If sportmasters or IMCO SC I would recommend -2 lowers to bring your X up. If standard lowers, you may want to think about filling the transom and raising the motors 2inches! It's a bit of work, but not that bad since you are already pulling everything to install ITS's.

I've got a set of -2 sportmasters, so yes I am raising my prop shafts. It seems that you have some experience with this set up. I really didn't add the ITS for any speed gain but more for the clean set up and hopefully better leverage/handling with the 7" set back. Most people just seem to leave 292's and 311's stock. I can't find anyone that has done much to these boats other than add more hp. In the past I was spinning 25 merc labbed bravos, and for testing I also picked up a set of fully labbed 27 (true) pitch Bravos. I'm expecting to have the slip go up a little but again, i've got nothing to base any of this off of. What is your thoughts on this?

I spent many years racing and being the setup person for Velocity Powerboats in Factory Class and Production Class. So Yes, I do have a good bit of knowledge, but it is all by the grace of God that this is comes natural to me! Did you run the -2 drives on your current setup? If so, with the ITS's your slip numbers will actually come down most likely. If you ran standard Bravos before and are changing to -2s with the ITS, your slip will be close to the same. Maybe a little higher or a little lower, all depends on how your boat likes the more efficient sportmaster cases. Most likely you will have a small speed gain, but handling should be more stable and much safer than standard steering. With the hydraulic steering creating a steadier drive going thru the water, the stand off will give you more leverage to carry the boat and possibly improve speed. What power are you running?

I've never run the Sport Masters on my boat. Up till now, other than the engines, everything is stock. Unfortunately everything is being changed all at one time. I would have loved to changed one thing at a time to measure the differences but I have to travel 5 hours to work on my boat. So that said, when I'm there I crack out as much as I can. As for power I'm running HP 450's. Prior my shafts were 7" below the running surface, now they will be 5" below.

you are going in the right direction, But 5" is still real deep. Did you consider Imco 12" x 3" up boxes. I think that you work real well on that Hull. Your doing a cool set-up now and I will be watching to see what happens. Good Luck

I did think of Imco's for a bit but I didn't want to raise the engines 3". If I do that I'm going to have to get rid of the swim platform because I don't think there is any way I can raise the exhaust that much and make it work, and I really don't want to invest in custom tails for Gil manifolds. I really like the way the ITS is a a self contained set up, we'll see how all this works. If the gains are minimal, then I may move everything up a few inches in the future. I've got a lot of projects this spring, and I have to travel a ways to work on my boat, so time is really limited. I'm really hoping to pick up 4-5 mph with this new set up. At the very least the handling will improve. In the past it was a handful at WOT.

http://www.cpperformance.com/c-396-tailpipe-wedges.aspx

these might help

As I'm set up now I'm good. I am already running wedges, which are great for small adjustments. A 3" raise though will require filling and re-cutting the transom or custom pipes. Which is why I'm going with standard boxes.

Time for an update on this project-

I've got the engines pulled, stock gimbles off and the new ITS boxes installed. Anyone thinking about this, I can't say enough how simple this swap was. The only thing I have to do in regards to the transom assemblies is rig the steering. Other than that, everything is in and hooked up.

Here are a few pictures of the progress.

I have been contemplating this for some time as it just seems the best, cleanest way to install external hydraulic steering. I am in the same situation as I would like to use my existing B1 drive. I am also very deep and was considering a -2 lower so you are doing exactly what I had in mind. Even though our boats are very different, the setup seems similar so I am interested in what your doing and how it turns out. Please keep us posted.

Dan

Dan-

I certainly will, too many of these posts end, and you never find out what the results were. I will be posting the results this project.

No truer words were ever spoken! Thanks. I look forward to the results. An ITS conversion would certainly help in my apparent quest to have the worlds most expensive Baja 252.

If that's the case, hang a #6 off the back :whistle::whistle:

777offshore - I am also in the process of installing an ITS with a bravo which has the Meritor style u joint assembly. Would you have any additional info on the the ITS yolk that will fit this? Maybe know of someone that still has one for sale or a part #.

I have a yoke for the non-sealed u-joints (older style). If you're interested let me know.

Ad27,

You can still buy both styles from mercury brand new. If you have the smaller style universals, you can only buy it as a complete shaft and u joints together. The larger size is sold as the extension shaft only. Endeavour says he has one, I would talk to him, the best I could find on a new one from mercury was over $500, and I believe that was dealer price. I bought a never installed shaft and universal from someone that responded back when I posted that I was looking for one. If you can't work out a deal, post in the wanted forum and you should find a couple.

Thanks guys for the info. I sent a pm to endeavor32.

TTT

Trying to rig up my spare drive to work with ITS. It is the standard small style. I realize you can buy the entire shaft, but did anyone figure out if there is a U-Joint assembly that would allow mating the larger extension shaft to the smaller standard bravo input shaft?

So time for a small update.

I finally got back to the boat and was able to hang a drive off the back to see with my prop shaft depth will be. I'm now 5" below the hull. So that's a 2' improvement over what I was, and adding the ITS box I lost nothing due to the transom angle.

Now for the bad news for those following this for the results. My 450 hp 454's will not be going back in the boat. I ended up buying a pair of 650 hp 509's. While it will be fun to see what this package produces. It will be hard to tell how much the ITS system and shorty helped. Now for comparison, Mopower, has a 272 with around 1300 hp and his top speed if I remember right was around 83 mph. So using that as a base line, maybe we can still get a gauge for what the drive package added.

Outside of measuring the prop depth, I spent most of the weekend getting the new engines, and shipping out the old ones. Next trip I will be focused on rigging.

From what I have found, you cannot run a standard Bravo with an ITS box. You would need to change the gears over to X gears and input shafts. There is no conversion that I could find other than what I just mentioned to do this.

That's what I was afraid of. Thanks for the update.