911 engine sealants

[snowman]

What do you use to seal 911 cases?, Valve towers, timing chain covers??

Do you use the orange stuff that Porsche used, or the newer better? red stuff thats the same thing? Or do you use Ultra grey silicone? OR some combination of gasket and sealant?

The real sealed engines should not leak a single drop for at least a few years, is there any such thing for a Porsche?

[TimT]

Dow 730, the white stuff.

[ChrisBennet]

I use Loctite 730 (orange cheesewiz) for the case and Loctite 518 for the cam towers. Both these sealants are anerobic (harden in the absence of air) so any extra that squeezes out doesn't harden and plug your piston squirters or cam spray bars. Do a search, there are some "gotchas" in sealing the case that aren't apparent from reading the factory manuals.
-Chris
Edit: Doh! I meant 574!

[kwikt 911]

Loctite 518 for everything. JMO

Kevin
72 911T/E [518+ mag case = no leaks]

[TimT]

I think we have some numerical conflicts LOL

the loctite is 574

dow is 730

[TimT]

Like this

[TimT]

hmmmm look on page 3147 and look for Dow 730.....this stuff works

[Bob Spindel]

I've used both the Loctite 574 (orange) and the Dow 930 (white). I think the 930 is marginally better because it is thicker and will tend to do a better job filling any small, minor imperfections in the sealing surfaces. On the other hand, it's a little harder to use because it begins setting up immediately upon exposure to the atmosphere, and you have to work a little faster getting the halves together (while dealing with all those rods and simultaneously making sure you don't jar the case enough to unseat one of the main bearings). With the anerobic Loctite, you have all the time in the world.

[ChrisBennet]

Originally posted by Bob Spindel
I've used both the Loctite 574 (orange) and the Dow 930 (white). I think the 930 is marginally better because it is thicker and will tend to do a better job filling any small, minor imperfections in the sealing surfaces. On the other hand, it's a little harder to use because it begins setting up immediately upon exposure to the atmosphere, and you have to work a little faster getting the halves together (while dealing with all those rods and simultaneously making sure you don't jar the case enough to unseat one of the main bearings). With the anerobic Loctite, you have all the time in the world.

You mean Dow 730 right?
I might not have the time you think when using the 574. Once you put the case halves together you need to get those perimeter bolts somewhat snug. Failure to do so has bitten me in the ass on a couple of occasions. I suspect, 575 starts hardening as soon as the case halves go together squeezing out the air.
-Chris

[vouvray]

Question...I use the Loctite where I have metal to metal conditions, like head-to-cam housing, etc. Where I have gaskets, I tend to use more of a silicone base, like at the timing chain covers, etc. Has anyone ever had problems with that?

[ChrisBennet]

Originally posted by vouvray
Question...I use the Loctite where I have metal to metal conditions, like head-to-cam housing, etc. Where I have gaskets, I tend to use more of a silicone base, like at the timing chain covers, etc. Has anyone ever had problems with that?

Sil.i.cone: Noun 1. Sealant that hardens when exposed to air so any excess that squeezes out of a joint forms boogers that will plug your piston squirters and cam spray bars. See: Evil

Gaskets go on dry.

[vouvray]

Oops. Thanks for the info and insight.

[snowman]

Yeh but the cam covers and valve covers still leak if you don't use something else. By leak I mean one drip per day per gasket. Still way to much for me. I am going to use silicone, very very carefully, on the cam covers next time. Use a very thing coat on both sides of the cam cover gasket. On valve covers I am going to try silicone gaskets.

[ChrisBennet]

Originally posted by snowman
Yeh but the cam covers and valve covers still leak if you don't use something else. By leak I mean one drip per day per gasket. Still way to much for me. I am going to use silicone, very very carefully, on the cam covers next time. Use a very thing coat on both sides of the cam cover gasket. On valve covers I am going to try silicone gaskets.

Jack,
I haven't had any problems with the chain covers leaking using the grey gaskets. Are you sure the drips you've seen come from the chainbox or is it oil the sneaks down the back of the box from the cam seal and settles at the lowest point on the chain box? BTDT
If you are going to try sealant might I suggest using something that is easier to get clean afterwards? I'm thinking it would be a pain to clean RTV off the gasketed surfaces afterwards. Maybe something that doesn't harden like Curil T? I wonder if DowCorning 111 would work?

I do get a "nose drip" on some valve covers on some motors but I've avoided sealants for the oil contamination reason. If you have a leaky valve cover now, could you let us know how the silicone gaskets work out?
-Chris

[mb911]

I have used a silicon based material before but don't care for it. Silicon based sealants uasally have to thick of squeeze to it and can promot bad things. I have used loctite 574 and 515 with good luck. The 515 only cures under compression but does not do the so called remelt but the 574 does. Just a side note I have a ton of the 574 if any one needs a bottle let me know.

Ben