Hmm. . . I never heard of 5900. . . the data sheet says it's black RTV.

http://tds.loctite.com/tds5/docs/5900-EN.PDF

5900 is recommended for 996 cars. From Pelican's catalog:


Dry as in Drei as in Three Bond?

http://www.henkelna.com/cps/rde/xchg/henkel_us/hs.xsl/1554_USE_HTML.htm?countryCode=us&BU=ut&parentredDo tUID=brands&redDotUID=0000000I61

See above. 5900 is an RTV silicone product - same basic debate as before, applies now. Search around and you'll see some of Henry Schmidt's 'crime scene' photos of overzealous use of RTV...

Well at least it was only about $16...so it's effectively the same as the Permatex Black RTV I bought...but also won't be using?

John, that may be what he was referring to. I wonder why it (5900) would work, and be recommended, for 996 cases but not be a good choice for earlier cases?

Hmm. Watch this video of the (Porsche-designed) Harley V-Rod engine. At about 2:54 there's a neat shot of automated silicone sealant dispensing. Perhaps this technique is used at the factory?

http://www.youtube.com/watch?v=W07TIsunO7Y

Threebond 1104 aka "yamabond" is probably what they were referring to.
-Chris

Actually, I asked if they had 1104 and they did not carry it or apparently use it. That's basically what led to the Loctite 5900 recommendation.

Let me throw my hat in the ring
 

I have done this about 8 times now. Here's my take. I've NEVER had a leak, not one, not anywhere. Not lying. I learned mainly from Supertec (Henry Schmidt) and reading extensively the specs. for the sealants. Also honed my techniques since the first time I built a 911 engine.



-Threebond 1104 on the perimeter. Much more gooey sealant that spans larger clearances better than 574 and is far less brittle. Threebond 1104 has been superceded to another sealant without lead, but it is still basically the same (THREEBOND 1194). I would try to get 1104 if at all possible. Go thin on this application, do it on the side WITHOUT the studs (rubber paint roller works great). In my opinion easier to work with than 574 and more forgiving, also.

-Dow Corning 111 is really crucial for the VITON through-bolt o-rings. Use the filed-down and smoothed Sharpie cap and make sure everything is lubricated well with DC111. NO black RTV. NO Blue o-rings for the through-bolts.

-Threebond 1211 on the #8 Main. Do not get any in the oil galley, very thin on this application as the factory advises no sealant here. Imagine a hard brittle anaerobic sealant like 574 (what the factory generally used) in this location. Not good, because the crank is vibrating around and would crack the 574 up in short order, and create leaks. I swear you will be glad you did a smear of 1211 on the #8. If this isn't right (very common place for a leak, without sealant), you have to take the entire motor back down. 1211 is much more flexible and pliable than TB 1104 when dry; it almost stays kind of liquid-y. This is good when there is a crankshaft inside the #8 bearing that is vibrating around.

-Smear of Curil-T on the flywheel seal. I now install the seal before I close the case halves, carefully watching to make sure the seal is perfectly flush with the case all the way around. You DO NOT want the seal recessed into the hole.

-Loctite 574 on the main saddles. 574 when dry has an extremely high shear strength to "lock" the main saddles together. Go VERY thin on this, to prevent affecting clearances and ESPECIALLY to prevent 574 squeezing onto the crankshaft and into the bearings...!

Torque the perimeter nuts first, then the end through-bolts, then the middle through-bolts. First you'll get nice alignment from the perimeter nuts being lightly torqued, and you'll guarantee that the outer clearances are perfect and you won't have perimeter leaks. Then you make sure the through-bolt ends are properly aligned with the crank, and finally torque the middle ones down in a nice, even (Wayne's book) sequence.

-Loctite 518 very thin on all gaskets (read: NOT O-RINGS, GASKETS). This is my own invention. Thinner than 574 and not as strong, but does not create brittle, hard gaskets that stick and tear. Works fantastically well on all the graphite chain box gaskets and the gaskets for the cams. Also this works very well on a leaky exhaust valve cover (due to large clearances and warpage), and is not a messy, "band-aid" solution. Very thin and red-colored anaerobic sealant that should only be used with a gasket, despite Loctite's claim that it is a "Gasket maker" liquid. Down the road, the next engine builder will thank you for having used this as the gaskets will literally fall right off with no residue, yet they won't leak until the engine comes apart in ten or twenty years. This sealant was designed for large clearances, much larger than 574. Henry's recommendation is go very thin 574 on the gaskets. I'll say 518 works better (no offense).

-Threebond 1104 on cylinder heads-to-cam towers interface. Again a rubbery silicone-type sealant that withstands vibration and does not get brittle like 574. Spans large clearances that this area tends to have, especially with slightly warped cam towers (I always resurface mine, but it happens).

Another great thing about TB 1104 is that it is a nice grey color that blends in to the aluminum very professionally and cleanly. Very much unlike the bright orange 574 that squeezes out and looks terrible.

ALWAYS WITH SEALANTS: Do not apply too much; worse than too little, in my opinion. It can very much affect clearances, squeeze out, look unprofessional and quite likely clog up oil passages.

Knock on wood (or else I know what I'm doing). NEVER a warranty job, NEVER a leak. Thank you Henry Schmidt for putting me in the right direction on the sealants. Anybody want more detailed info I can point you to the pdf's for all these sealants and show you the precise engineering reasons for using them in a given location.

No doubt other manufacturers have very similar, competitive products that MAY be interchangable with any of these. However, my experience, ease of availability and personal recommendations have led me to these conclusions, and I now have a fair amount of personal experience to back this up. Your mileage may vary, but this has worked flawlessly for me.


Good luck,

Scott

KinderSport

Scott, thanks for the suggestions.
For some reason I could not specifically remember putting the seal between the case halves at the bottom, even though I could not find it in the garage. I finally couldn't stand it any longer and took it apart Saturday afternoon. It was in there, right where it should be! At least I'll know 100% for sure this time (I'll take a pic!) and I'll probably go a lot smoother on the next time around when sealing the halves back up. The 574 looked okay on the perimeter but I may have gotten it TOO thin, if that possible. Most areas had very little squeeze out...just tiny rib, but maybe that's best. My other concern was the 574 on areas which were EXTREMELY close to bearings and such but I noticed no squeeze out into anything moving.

Dow 55 is what I used for my o-rings, which I got from Henry @ Supertec along with the viton o-rings.

i have had my engine builder rebuild my engine twice because of not using sealant. The engine is still leaking after his second try, mostly from the through case bolts on both sides as i can tell.
Can this be repaired without pulling the jugs out of the case.

Any idea which through bolt o ring he used? I started out with the crappy blue ones and they shredded then I did what everyone told me to do in the first place and went out and got the green Viton ones. They did not shred at all but several knowlegable people convinced me to NOT use the black RTV silicone that Wayne recommends in his book. Hopefully I won't have leaks, or at least they'll be minimal.

Can someone please explain how 574 squeezing onto the crank or bearings will have ANY affect?

The stuff doesn't set if it isn't between the mating surfaces and will simply wash away in the oil. What am I missing here?

574, when applied too aggressively, will indeed skin over and clump up inside the engine. Someone even posted a thread about a 574 chunk-related engine failure. Bearing or cam spray bar, I can't remember.

A great exercise for the DIY builder would be to take a bare case - no bearings, layshaft, crank, pump, etc. - lay down 574 in a coat they feel is appropriate - torque down the case, and then tear it apart. If they're like me, they'd be shocked at what they found squeezing out inside. I'm betting they'd use less than half the 574 the second time around.

Actually, that happend to me. I sealed it and then found that an IS bearing had been dislodged by a case stud. I tore it appart immediately and then resealed.

The amount you see squeeze out on the outside of the case will likely be the same as the amount that squeezes out on the inside of the case.

The last thing that went on my engine was the sump plate. Looking through the opening I could see 574 on the inside of the case (squeezed at mating surfaces). It was still as wet as it was when it was applied. Therefore I don't see how any clumping could occur. It just doesn't compute. Again, the oil will wash it away.

I respectfully disagree that 574 can create problems if used in excess. I will be the first to post results if 574 turns out to be the demise of my engine.

Your disagreement is noted, but this has been documented. Squeezout on the main webs or inside the parting line isn't going to do anything and yes, oil will wash it away. Other areas, such as thru-bolt passages, where squeezeout can collect, can definitely skin/clump into a semi-hardened state and cause problems.

All completely moot if the 574 is applied properly.

Maybe the clumps will keep the through bolts from leaking ;).

Thanks for the info.

After having sealed my case twice ... I can say that it really doesn't take much sealant. When I opened it up to fix the IS bearing, I noticed that most of the sealant had squeezed out. Little was left on the main webs (in some spots it seemed like none was there).

So, for those following this thread I would certainly say "less is more".

I could not stand to read this thread without adding my experience.

I put the case halfs together 'dry' without the crank but with the bearings and oil pump to see how closely everything fit. It stood off by a 1/4 inch until I knocked it down and loosely tightened a fourth of the fasteners. No gaps, everything was even. I tried using the blue o-rings and they galled up as the through bolts were tightened - of course I had the green ones already, I just wanted to see how bad they were.

Next I placed the crank, and IS and brought the case halfs together easily with a few evenly and lightly tightened fasteners. This was all good practice and checking to see if everything was 'right'. I knew I could do it solo too.

I decided to assemble the through bolts without the o-rings. I sidestepped my concern about missing the o-rings when I placed them later by initially putting the bolts through 'backwards', I had an obvious way to confirm that a bolt had been o-ringed later when it was removed and placed the normal way. Counting the rings helps too of course. I see the greatest risk of o-ring problems occurring if they are present before the case is together and get moved along the bolt by the washer, especially without a good lubricant. My blue trials suffered their fate at that step. A few hours later I removed one bolt at a time, added lubricated o-rings with the Sharpie cap and put them in normally to torque. I remembered to do the two acorn nuts under the oil cooler too.

The other factor that gave me confidence was getting all the fasteners, washers, bolts threaded before "going anaerobic". I haven't read this before but it made sense to me. My case stayed about 1/4 inch apart which was enough to get all the fasteners ready. Then I knocked it down (20 min after the first 574 was spread) and started incrementally tightening, never too much anywhere until it was even and tightening up. I used an electric driver and used each torque setting in turn. My time from contact to full even torque was about 5 min. The 574 was liquid with an even small squeeze out. No leaks at 100 miles now.

I did a practice run myself but it was by accident...as mentioned before, I could not remember putting all the o rings in (I had, BTW) but the second time went much faster and it was far less stressful. I can imagine how this would go after doing it 20-30 times. The point it, do a practice run, it really helps.

I'm not so sure you should place a lot of faith in the anaerobic qualities of 574 under those circumstances. I couldn't confirm this with a web search but I believe 574 metal ions as well as the abscence of air is part of the recipe for hardening. I believe (and I could be wrong) that 574 will start to "skim" as soon as you apply it to the case.

I don't use it anymore but I'm curious enough about this that I might try an experiment to confirm this "skimming" behavior.

-Chris