29 Nu Era & IMCO SCX upper and lower
 

Well I am getting ready to purchase a IMCO SCX upper and lower. I have been towed in from the Pacific Ocean too many times and Bravo is no longer part of my vocabulary. I am only running about 725hp and my gears have been fine with no pitting. The issue is I keep breaking the lower Vertical Shaft and I am done. 80% of my boating is in the ocean and a 30' boat with a full tank of gas, ice, food, drinks, 2 anchors (You get the picture) is just to much weight for a single Bravo while skipping along at 50 - 70 mph IMO. I looked at all American Drive Service with their Cryogenically treated parts but spoke to people who told me it broke on them as well. Since I can not fit a Transmission in my boat nor have the $ for a #6 the IMCO SCX seems to be my only choice.

This being said I was told the SCX lower unit is 2 inches shorter than my Bravo. I am using a Hydromotive P5x and was hoping I could get away with not adding a spacer or if I do only add a 1 inch spacer. Those spacers are $600.00!!! and IMCO does not have a Test Program to see what spacer will work the best. Does anyone have any experience with the SCX drive and what spacer, if any, is needed on a single drive 29 Nu Era?

I also spoke to IMCO about their option of Blueprinting the lower unit but they told me since I am only reaching about 80mph, the Blueprinting may not do much for me. Get over 100 mph and the Blue Printing starts to make a difference. The Blue Printing is about a 1K option.

By the way, I know I can break a IMCO SCX. I understand they are not bullet proof but for my application the SCX should be slightly over kill which is what I am looking for. I am just hoping to get 3 seasons of boating per out drive issue vs. 1/2 - 1 Season per drive issue. As a note i change my drive oil every 15 hours and never seen any chucks of metal on the magnet or oil drain pan.

Any feedback would be appreciated.

Jimmy,

I will be 100% honest, you will be the first 29 NuEra equipped with an SCX. Lavey has built one 2750 and one 28 EVO with an SCX but both boats ran the SCX with -2 SC lower option because both customers didn't want to lose speed. Now, I understand and know the type of boating you do, I have driven your boat after the original engine refresh so I know the power of the engine, and if it were my boat I would do the full SCX outdrive. When a huge majority of your boating is in the ocean, losing 5 mph top speed isn't much of a concern but gaining a lot more reliability is a great plus! I've done the whole 5mph idle speed back to the launch ramp from 12 miles off the coast due to a broken outdrive, and it is not fun!

In regards to the SCX being 2" shorter and should you add a spacer... Yes the drive is shorter in depth, but it is also longer in length over a standard bravo style drive. A solid rule of thumb in pretty much every boat is that anytime you extend the prop aft, you also raise the height of the prop. So if I did the full SCX swap I would not add a spacer unless once the boat is ran it is obvious the X dimension is too high. You are already running a 5 blade so you will not have to worry about losing a ton of grip by going up 2" and you will most likely not have to change to a higher pitch thats commonly done when raising the X because of the fact the SCX takes more power to turn and also creates more hydronamic drag.

If you do in fact do this conversion I highly recommend working with my dad so he can drive the boat and help you figure out which direction you need to go for the X dimension settings. Every boat manufacture model is different and the same setup changes don't work for every one. The NuEra bottom is different than most and maybe even a little harder to know exactly what it needs. But he will be able to tell you exactly what it needs as soon as he drives it.

Chris, I know you guys have put some big Teague engines in the 29's so what drives were your customers buying?Or maybe I misunderstood what you said about my 29 would be the first to have a SCX?
I was going to call your dad but I figured he was getting slammed right about now. I wanted to do some further research so I could understand what your dad recommends. Like always you are very helpful with a wealth of knowledge. I hope you are doing well Chris.

Jimmy

One of the Teague 29 NuEra's was built with a Bmax drive and the rest were built with Mercury Bravo1 Teague Platinum drives. Most of the TCM 825 with the platinum drive setups are running around mid 90's. The best setup 29 NuEra TCM 825 and platinum drive runs low 100's. The Bmax boat had a TCM 1000 and only ran low 90's so it lost a lot of top end with that drive... These boats outdrives see a decent/average lifespan, but they are all lake driven boats. You are basically a pure ocean boater and that has a huge role in how long your drive is going to last. It's not a fair comparison on outdrive life to the other TCM powered 29 NuEra's.

We have been battling the same with what drive, then the transom assembly set up, then with what X and then the props and so on and so on. Other things that come in the mix, Set back boxes and whether a 2 inch shorty or the SCX 4. Really very hard to say what set up is going to be right for one specific app and how that boat is set up. IMO using the SCX and the SCX you are going to loose speed regardless. It would nt surprise me 3 to 8 mph loss. Again IMO.

The + side is reliability.

Really what it boils down to is money and testing different combo's and having the time to do so are the 3 huge major involvements here.

Thank you for the feedback.
I spoke to Chris Sr. this morning and he recommends the Standard SCX lower which has the length as the Bravo. My Bravo seemed to work well. No porpoising, great out of the hole and min. Chine in the upper speeds. The only thing I am struggling with is would I only loose 3 mph vs. 5 or more, if I purchase the 2" Shorty and add a 1 inch spacer.
Yes, I am pretty bummed out about spending 18K and loosing 5 MPH plus but I have to choose reliability over performance. My Merc Racing 575sci has such a good bottom end and with the Intercooler I will just increase the boost. If need be, I will refresh the Top end in about 250 hours. I rather know that I have to tear the heads off ever few years in the Winter vs. Russian Roulette when I am vacationing in the summer.

the standard SCX is a 2 inch shorty compared to the standard bravo in less something changed recently with IMCO ?

You know you beat me at buying your boat - 16 hours ahead of me. I flew out with check in hand and Jeff told me that he had a deposit on it. Jan 2011 or 2012 around that timeframe if I recall correctly

BUP,
That time frame sounds correct. It's all about Timming. There was a 2750 I was looking at a few months before I purchased the 29 but I did not jump on it quick enough and it got sold. I was supper bummed I missed out but I am happy with what I purchased. Used modern day closed bows are hard to find in the Western States. Thank you for the advice and knowledge

Just to revisit this topic.

I have confirmed that the full Imco SCX outdrive is in fact 2" shorter than the Bravo and Imco SC outdrive.
The bravo/SC drives are 22 1/4" crankshaft to propshaft and the SCX is 19 7/8"
So an exact number is that the SCX is 2 3/8" shorter.

If you do decide to swap over to the full SCX I would personally start with out any spacer and still run your existing prop.

Thank you Chris,
I picked up my full SCX drive last Thursday and installed the Oil Reservior and Bell Housing Helmet over the weekend. Replaced the lower shift cable and bellows as well. I will mount the drive this week and take her out for a test ride this weekend. I purchased the drive withOUT any spacers so I am hoping my Hydromotive PX5 will be enough and I won't need any spacers. I will report back with my stats next week.

Bravo/sc is 22-1/4"? My bravo X measured 21-7/8 input shaft to propshaft, hence the 2 inch and 4 inch shorter designations with the scx and scx-4 . So the standard length SC lower is 3/8" longer/deeper?

Jimmy any indepth details how the change over went switching to a IMCO SCX ? Handling, turning , low speed handling and top speed handling plus MPH numbers compared to your last set up ? THANKS

And info on the final results from the change over ? good or bad or no differ

anything for news about the SCX install - how were the results and what type of boating on what body of waters ?

Curious how it handles and if you can feel the speed diff, but I doubt it if you are on the ocean.

UD

Dave he did mount this with no extension box

Wow, sorry but I have not logged onto OSO in months. Is there a way for Post I create in OSO to email me if there is any activity? I had no idea members were waiting for my response. Everyone has been very responsive when I asked for help so I am truly sorry for not reporting back.

So the install of the SCX was pretty smooth except one of the screws that hold on the Pivot pin for the helmet which snapped and I screwed up the threads. I had to rotate the Pivot Pin and redrill new holes and threads. Oh yah, make sure you purchase a new Water inlet connector. This is the connector that passes through the Transom plate. It is plastic and it will break. I spoke to my bother who is a boat mechanic in Cape Cod and he said they do tend to break when removing the water inlet hose. Kind of PIA to replace. Not rocket science but requires patients and a lot shipping blankets so you can get comfortable as you laying across the stringers and stuff in the engine compartment.

In regards to performance I did notice a difference. IMCO and others said I would loose about 5 mph. That's pretty accurate. For me I lost about 4mph. However, I ordered the stock IMCO SCX drive which is 2" shorter than my stock Bravo. I did notice the boat gets looser quicker as I trim up. With my PX5 28pitch prop I had no problem getting on plane on Lake or Ocean. I think I did generate more prop slip and I am above 20% most of the time. I know that is too much so I think I want to try a 5 blade 29 pitch on my modified 575sci. I have the Teague 700hp superchiller kit so I should be pretty close to that plus I installed a Roller Cam and a Blower Shop replacement blower so I want to believe I am at 725 hp.

If playing with Props does not help my Prop Slip I will order the 1 or 2" IMCO spacer. I can't believe those spacers are $500. Matter of fact, if anyone has one they are not using I would love to borrow it. I will write check or provide cash as collateral. Matter of fact 100.00 rental would work for me if someone wants to re-coop their investment

I can't even tell you the piece of mind I have now owning this drive. IMO I don't think any single application sport boat that is 28' or larger should have a Bravo. I wouldn't even purchase as the IMCO SC or Teague. I snapped 2 vertical shafts which are the same shaft at the SC or Teague. I understand that you can get some further strength by Cryogenically treated and REM polished technology but I was so over with trying new things. Plus the wife said we either spend the money to make it right or we are going to be proud owners of a Sea Ray. I'm not ready for a Kitchen boat yet. LOL

Again my apologizes for not keeping up on this thread. Below is my email address if anyone wants to email me private

[email protected]
Jimmy Biro 29' NuEra Miss Tasty

Uncle Dave is correct. I will never get the boat to full speed in the ocean but that is where the SCX shines. To many swells to keep the 29' Nu Era grounded at 70mph. I have total confidence when cross over to Catalina, which we do a lot.

Lake Havasu WOT 5400 RPM
Bravo - 80 PX5 28
SCX - 76 PX5 28

Did you get the "blueprinted" lower that IMCO offers? Just curious

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After speaking with IMCO they said the Blueprinting would only save me about 1 mph based upon a 80 mph Single Application. If I had Twins running over 100 mph it would probably be worth the extra 1K for the Blueprinting.