Case Sealer

[Superman]

John, what's up with the metal thing in the Garko box? Looks like a tiny bottle opener.

Also, I have opened the case of my engine and while I am not surprized to find everything looking NEARLY NEW even after 183k miles, I am surprized to find virtually no trace of case sealer anywhere along the mating seam. I thought I'd have to clean the gunk off. I can't imagine using such a small amount of sealer that none goops out when I torque the nuts.

Oh, and by the way, you guys who've told me about worn intermediate shaft bearings.....Yes I see they are worn through to the copper, but that silver coating over the copper must be only about .00000001mm thick because that shaft is still tight in its bearing shells. It's still what machinists call a "honeymoon fit." I'm not bummed that I split this case, but I did not need to.

[john walker's workshop]

the metal thing works good on your toothpaste tube to wind it up. i suppose you could use it on the dirko tube also. too small to open beers. sardine cans too, but they come with their own crank. the factory sealer was applied with a little roller, so there wasn't much extra. any stuff imbedded in the main bearings? make sure there's a tiny bit of sealer around the #8 nose bearing o ring, so you don't pull a leland.

[Doug Zielke]

Originally posted by john walker's workshop
.......make sure there's a tiny bit of sealer around the #8 nose bearing o ring, so you don't pull a leland.

Oh, oh, John!
Leland is gonna get you back for that one come July 13!!

[ChrisBennet]

Originally posted by john walker's workshop
make sure there's a tiny bit of sealer around the #8 nose bearing o ring, so you don't pull a leland.

Hi John,
Could you be extremely specific about this point?
I had a leak around the #8 the first time I rebuilt my motor. I tore it down and redid it using more 274 the 2nd time and it didn't leak but I don't know if I just got lucky. I'm rebuilding it again this spring (broken pistons this time) and I don't want to ever have to split that case again.
I realize you're a busy guy so don't feel obligated to answer but if you could it would be much appreciated.
TIA,
Chris

[Superman]

Only a little bit of sealer around the nose bearing o-ring, John? I was prepared to do it the American way and make SURE it does not leak there. Sealer can coat that whole bearing as well as it can coat the o-ring. I know, I know. A little dab'l do ya.

Does the Dirko go on both surfaces? The directions would seem to suggest that both surface be 'wet.'

[Leland Pate]

Ouch!

I deserve that one.

I still don't know what I could have done wrong.
... I didn't "slim" the stuff in there, ...but I did make sure it had a thin, even coat of 574.

And I lightly lubed the O-ring with DC 111 to boot.
If I have to do it again... I'm not going to use the 574.

[Superman]

Leland, the stuff I am going to NOT use is the Dow Corning 111. DC 111 is great on stuff like the oil return tube o-rings, which move around during their life. That nose bearing is not going to move at all, so there is no need to put a flexible lubricant on the o-ring. At least this is my theory. I plan to fill that area with sealer.

[john walker's workshop]

the old 574 loctite is wierd stuff. it cures when deprived of oxygen. i used to use it a lot, but on one 930 engine a while back, there was a nose bearing leak, requiring of course a complete teardown. come to find out the 574 had not squeezed out as it should have when the case halves were torqued. there was enough between the cases to keep the nose bearing o ring from being properly compressed. maybe i got a bad batch, or maybe it was old, but i have been using dirko since then with good results. superman would be correct in saying the nose bearing o ring does not move, so a thinnish layer of sealer around it's contact area on the case bore and around the o ring itself should insure there will be no leaks. also, on reassembly, when the case halves are still an inch apart, check all around to be sure you didn't wipe any sealer off when you were juggling the rods and chain into position, and double check that the square cut red o rings are still in position on the oil pump and in the case half. just behind where the alternator housing sits on the case is another potential leak area. it's the thinnest cross-section of the case, so check that too. torque the thru bolts first then the nuts around the outside. always torque from the center to the outside.

[Tim L]

For an o-ring to work as intended it must be free to move. If you goop it up with a hard sealer once that sealer cracks from the expansion and contraction of the case to nose bearing, I think its going to leak. I'm no expert but when I sealed my case I was very carful not to get any locktite in there that might harden and impair the sealing of that o-ring. I don't think they would have used an o-ring if they didn't expect it to move.

Tim

[john walker's workshop]

the 574 hardens, dirko stays rubbery.

[GIBSON]

Super, when I split my 73's case there was almost no evidence of
sealer except on the bottom corner near the flywheel end. That was it.
I'm glad you're intemediate shaft was ok, mine cost me an additional 550.00 to replace. Did you mic the journal surfaces? Just curious to see what numbers you got on yours.

Bruce

[Superman]

I don't have a mic. I wasn't going to mic it either, since the journal surfaces look like they were polished yesterday. Absolutely beautiful with no hint of radial scratching or wear whatsoever. Again, these journals look like they just come back from the machine shop. Except one. And now I am very worried. That story is in another nearby thread.

[Doug Zielke]

John,
I wish you'd write a book on Porsche mechanics. I have nearly filled a loose-leaf binder with your insightful posts.
Hey...come to think of it, John, you almost *have* written a book!

(Yes, I know our BBS host is at work on a engine book, but can anyone beat a guy like Mr. Walker when it comes to know-how??)