Thread: mjh3ides' SHO Rebuild
09-01-2010, 10:25 AM #1
mjh3ides' SHO Rebuild
Last summer my SHO had an overheat which damaged the exhaust threads in both the head & manifold. I had replaced all the gaskets & hardware & sealed it with ultra copper & never had any leaks, however I was worried about running a bigger boost wheel before having a time-sert repair done because none of the bolts could be torqued to spec without stripping them. I've been sitting on a spare low hour SHO engine for awhile that was planned to be rebuilt for a GPR-SHO project. Since I plan to completely rebuild a motor for that project I decided to drop the low hour motor into the SHO & rebuild my 190 hour engine.
Once the SC'er, intercooler, manifolds & wiring harness are out of the way it's a pretty straight forward process pulling the engine. It's kind of a tight fit getting the aft mounts on the engine past the deck opening, so it makes it much easier having two people...one to operate the hoist & the other to turn & tilt the engine until it's clear.
09-01-2010, 10:35 AM #2
Before dropping in the new engine, I installed a lightened SC'er drive gear that Bill Chapin at R&D did for me. I didn't weigh it before sending it out, but another forum member had weighed his unmodded drive gear at 458g so the weight reduction on mine was 40g.
see post 18: http://www.greenhulk.net/forums/show...ht=clutch+rius
I only plan to run either a B1 or C3, so hopefully this will help extend clutch life. I doubt this we be a cure-all fix, but since I won't be running a bigger wheel I'm hoping it will make a difference.
Although the other hardware showed no signs of wear, I still replaced the thrust washers, snap rings & pin that the gear spins on. Unfortunately, the bearings are not sold by themselves, so you have to buy the whole gear assembly to get replacements. I removed the bearings before sending it out & it came back with new ones installed. Thank you Mr. Chapin. He also had it turned around for me in one day, so I'm very happy with the service from them.
09-01-2010, 11:17 AM #3
I had a high pressure water leak that started at Mudbug & I found out why while swapping engines. The int. housing was TOAST, even though I've been religiously pumping grease into the zerk fitting every 25 hrs or so. I dont know if the hose got clogged with old grease or something, but the whole assembly was completely dry & corroded & half the bb's were missing. I guess they must have disintegrated because there's no sign of them in the hull. Luckily I had a spare to install, but now I need a replacement for my GPR-SHO. If anyone has a used one they want to sell let me know. My housing only had a couple marks on it & might be able to be reused, but the shaft, bearing & seals were destroyed. The replacement cost on some of these parts is insane. I priced out replacing everything from Riva's OEM parts list & it came to $650, not including the coupler.
I didn't have another coupler, so we had to transfer it off the old shaft...it didn't come off without a fight. Luckily the removal tool for the GPR fits the SHO coupler, so after heating the shit out of it we finally got it off. Without an impact it would've been impossible to get off.
The first pic shows what we did to prevent this problem in the future. A short piece of hose with a grease fitting replaced the long hose. Hopefully this will make getting grease to the housing easier.
On the bright side, I should gain back lots of rpm now that it's fixed. I'm guessing it was costing me some speed even before completely failing. The only PITA now is the alignment of the pump changed slightly with the new housing. The impeller is now rubbing the top of the wear ring. I will be resetting the transom plate anyway, so I'm going to try & make sure it's as high as possible to fix the issue. If that doesn't do the trick I guess I'll shim the int. housing & realign the engine to match.
Last edited by mjh3ides; 09-07-2010 at 02:50 PM.
09-01-2010, 11:39 AM #4
Getting a little ahead of myself, but here's a list of some things I will be testing once I'm happy with the reassembly.
- I have a new idea on blueprinting the transom plate to the shoe that shouldn't cause an overstuff
- R&D vs Riva grate...once I decide on which one to use I'll be sealing the shoe & filling the bolt holes with epoxy.
- C3 vs B1...just ordered the C3 & since I have 2 SC housings I can do a proper back to back test
- Prop testing...155 Skat swirl vs 155 Skat longblade vs 160 Skat swirl vs 155 Solas DF
- Stock ride plate vs Jim's modded stocker vs Jim's modded R&D...already kind of know what the results will be but have never tested all 3 back to back
- No back to back on these, but I'll be throwing in the Riva cooler & ported throttle body that Rossnemo did for me.
- I've already removed the R&D cooling kit because it caused GIO with the t-stat removed & will be installing Riva's kit.
- I also picked up a Riva RRFPR, but I'm going to see how how it runs with the stock regulator first.
09-01-2010, 12:34 PM #5
- Join Date
- Oct 2005
I know this is going to come out well!
Have fun with the build!
09-06-2010, 08:55 AM #6
09-07-2010, 02:46 PM #7
go big or go home . . . NICE !!!!! great work and write up mark !!!
09-08-2010, 09:41 PM #8
09-08-2010, 09:58 PM #9
Alright, here's how it sits now. Tomorrow I plan to get the transom plate reset, fit the Riva cooler, reinstall the int. mani & get the wiring harness attached. Then Fri I will finish up with getting the exhaust back in, water routing done & pray she starts up. I've never fired this engine since I bought it, so there will definately be some butterflies in my stomach when I hit the green button the first time.
If you notoice in the pic, there isn't an inch of stock water hose left. It's all been replaced with the synflex stuff Riva sells & all the stock clamps have been replaced with oetikers...do it right, do it once. The blue hose in the hull is left over from the R&D IC cooling kit for the stock IC, so all that will come out tomorrow.
09-08-2010, 10:33 PM #10
Well, what was supposed to be a quick project installing the Riva SC'er shaft & replacement bearings turned into a project that took hours. The last time I had it apart was probably 60 hrs ago & there wasn't a hint of corrosion, but I guess I haven't been as fanatical about maintenance in the last six month & it showed.
There was quite a bit of surface corrosion that had to be cleaned up. Not sure if this is the best way to do it, but I used some 1000 grit wetsanding paper to carefully remove it & then used a couple polishing wheels & white oxide clay bar compound to shine it back up. It still shows the discoloration where the corrosion was but it now has a polished smooth surface again, probably more so than when it was new.
I did have an oh shit moment after getting the front of the housing off though. I've had the thing apart probably a half dozen times without issue, but this time the corrosion had fused the front housing to the main assembly. After spending a half hour spraying WD40 into the SC'er exit, heating, & trying several methods to gently separate the front housing I went to plan C...leverage. I stuck the handle of my mallet into the exit tube & tried to gently pry it apart when all of the sudden it popped free, but not so gently. After a brief moment of celebration I noticed a chip missing from the leading edge on one of the blades of my C1...SHIT! You can bet I'll be spraying some rust inhibitor into the intake every few hours from now on. Might even start using the outerwear for the Riva intake when riding in salt since I had what looked like salt deposits on the SC'er intake.
Here's some pics after the clean-up:
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