KenRudd

Ed Scherer

OK, I don't want to beat a dead horse here , but I'm going to be putting my head (cam/valve) covers and intake back on this weekend and am still uncertain what to do with respect to sealants. I've updated post #1 in this thread with a photo of all the stuff I've got on hand, which is pretty much damn near everything. And that includes some of what I believe to be the slightly harder-to-get "good stuff" like Yamabond 4, Drei Bond 1209, and Loctite 574.

In my particular case, the one possibly unusual thing is that in inside surfaces of my covers and intake end pieces are bare metal, not coated (they were powder coated on Monday; the insides of everything were blasted down to bare metal and left that way). Here's a close up of a the gasket channel on one of the head covers. The texture is a little rough; it feels kind of like a kitchen knife sharpening stone. It's very clean, though. You can see (it's kind of dark, though) that the powder coating stops very nicely at the outer edge.




Head (Cam/Valve) Cover

The WSM (and/or TSBs) as well as conventional wisdom specifies a sealer at the corners (head side), but otherwise, apparently the gasket generally stays dry, but probably a little gasket sealer/maker in the channel on the cover to hold the gasket to the cover to make it easier to deal with during assembly.

But... worf928 told me in a PM: "I've used the Rubber Gasket sealant [Ed: I believe the product referenced is Permatex 85409 "Ultra Rubber Gasket Sealant & Dressing"] and the Ultra Gray [Ed: I believe the product referenced is Permatex 82194/85084/82195 Ultra Grey® Rigid High-Torque RTV Silicone Gasket Maker] with good results. I don't have enough time with the former to say for certain, but I KNOW the latter very works well. I've never had a leak from one where I used the Ultra... and... in fact, if you ever have to go under the cover again the Ultra keeps the gasket on the head (assuming you only do the head-side of the gasket with the recommended amount and only enough to keep the gasket in the cover during install) so you don't have to mess with it when you put the cover back on."

But... Mrmerlin in post #2 in this thread suggests: "For the the cam covers unless you have a perfect cover ( the gasket groove is usually rough) put a bead of Hondabond 4 into the gasket groove just before you set the gasket onto the cover, (dont forget the spark plug gaskets, they go on dry). Also when fitting the covers there is a small dab of HB4 applied to the junctions of each cam cap to head surface, ( 4 dabs per cover), when you take the old gasket out you should see a dab of white sealant scrape this off first."

And... Bill Ball says elsewhere: "As to Yamabond or other sealants on the cam cover gasket, all I have ever seen and done is 'goop' in the corners as indicated in the bulletin below. The hardest part is to get the gasket to stay in the cam cover groove as you maneuver the cover back on around obstructions when doing this with the motor in the car. Use some gasket cement to glue it to the cover and make sure it has set well before you attempt to put the cover on. Put some 'goop' in the corners of the head as indicated by the 'A' arrows, running about an inch up the cam cap and an inch on the head."

So... this leaves me wondering... what the heck do I do for mine? They look nice and clean, but the surface is slightly rough.

Do it "by the book?" (generally dry, but maybe with Drei Bond 1209 at the corners of the head mating surfaces), or... (given what my cam covers look/feel like and worf928's and Mrmerlin's advice above), Yamabond 4 top side? and/or Permatex Ultra Grey bottom side?

Oh, and I've also heard different things on the spark plug hole seals, too: dry, or same stuff you use on the gasket corners top side only (helps hold them on during assembly), or same stuff you use on the gasket corners both sides.

Arggghhhhh!!!!



Intake

OK, I'm pretty sure that the intake to head gasket can go on dry, but ... how dry? Would a little Dow Corning 111 smeared all over it be called for? (From Mrmerlin in post #2 in this thread: "Another note my other favorite is a tube of Dow Corning 111, a non setting silicone sealant. I apply this to all of the rubber O rings; it seems to keep them softer, ..."). I've used 111 (based on previous recommendations, from Borland, I think) on the O ring at the water bridge to block interface, as well as the thermostat seals (both front and back). Would a quick rubdown of 111 be wise on the intake gasket? Or would that make it squish around and deform? How about the side plates on the intake? Totally dry, or would a rubdown of 111 be a good idea there?



Getting This Information Organized and Documented

I'm still committed to organizing everything I learn into a nice reference and updating post #1 in this thread accordingly, but I need to deal with my immediate problems first.

I noticed that a few people are bookmarking this thread one way or another, which tells me that there's at least some interest in learning more about best practices and 928-application-specific choices for sealants, threadlockers, anti-seizes, and lubricants. Why don't you guys check in here again and tell us about your challenges and what you'd like to know: what would you like to see in an organized reference document on this topic?

Mrmerlin

ED your going to want to use any type of the sealers mentioned for running a bead in the cam cover gasket groove.

i only have experience with the HB4 i know it works for for running a bead into the cam housing gasket channel then putting the rubber gasket.
it wont leak for many years if you do it this way .
I dont have any experience with any of the other Drei bond sealants,
dont forget a small dab at each cap to head junction so the gasket wont leak ( 4 corners)

For the intake gaskets dont use any sealants or DC 111 on the intake gaskets.
but do use DC111 for fitting the injector seals to the manifolds and fuel rails they will slide right in and stay soft if this is followed, Use DC 111 on the rubber O rings for the intake side plates and the flappy O rings seals inside the bearings

Ed Scherer

OK, I've got the YB4 (same as HB4, right?), can do. Sounds like that'll make assembly nice, too, with the gasket well attached.

So... bottom side of gasket dry? (noting that corners will also be sealed with YB4 that will be applied to head/cap side as you mentioned and is well documented elsewhere). Any harm in YB4 on one or both sides of spark plug hole seals? Based on what I read, YB4 isn't hard to clean up with acetone, but I guess the one possible downside of using it on both sides of any seals would be difficulty in future removal of the cover.

Anyway, from another thread (that you also you participated in), one of the posts (not by you) said, "I put new cam cover gaskets on and it [Ed: the leak] didn't stop either. When I painted a thin layer of Yamabond on both sides of the cam cover gasket (cam cover and head surfaces that mate with the gasket too) all the way around and re assembled the leak stopped....". This is the kind of stuff that scares me: finishing this job up and then having leaks. Of course, I don't want to use sealants where they're not needed, either, making future disassembly or clean-up difficult.

OK, all that makes sense; I see little to worry about on any of that.

Thanks again for your help.

Landseer

A nice excel chart on this would be a great thing.

Would go great with a condensed and completed version of Robs torque chart.

I'm working on one for 83/4 electrical.


Simply. Condense. Display in readable form. Huge gifts for those that follow.

Though, that CD set is a work of art, too. Condensed in a different sense I guess.

Mrmerlin

well if the head surface is smooth then the rubber gasket should seal without any additional sealants.

I would put the spark plug seals on dry unless the area around the cam cover is bead blasted and has a finish similar to the gasket groove,
if so then by all means add a bead to spark plug to cover surface leave the head surface dry

Landseer

I've been using felpro hi-tack on a lot of gasket surfaces.

Fogey1

I've bookmarked this thread. Thanks, Ed.

I'll love it even more if you take lots of before, during and after pix. For instance the bead you lay in that valve cover and the gasket corners, etc.

ww

Ed Scherer

OK, this should be enough to get me through the weekend!

Back of spark plug holes (inside of cover) is, in fact, blasted bare, so I'll seal it with YB4, too. I'll make sure that all the aluminum surfaces (like the head, intake, etc.) that won't have a sealant are nice, clean, and smooth.

Thanks, again, Stan! I think I can proceed with confidence now. And your explanations (and taking into account the nature of the surfaces involved, etc.) help me understand the rationale for the recommendations.

Ed Scherer

Hmmm... I guess I can take some photos. It'd be nice if someone more experienced (I'm a first timer on this) could lead the way with photos, though; they'd be much more likely to get it "just right". I may just wind up thoroughly documenting my mistakes.

Ed Scherer

Noted. Thanks for the suggestions.

Mrmerlin

Great i hope your leak free ,, Keep Em Flying!

Mrmerlin

BTW what kind of block off plugs/pins do you have in the heads where the cams are not in the cam caps??
if they are the rubber type then they should be swapped out for the new PIN type

Mrmerlin

read this link it has pictures of failed oil plugs and the new pins.

https://rennlist.com/forums/928-foru...-the-plug.html

Ed Scherer

BTW, a few months ago when I was doing a timing belt / water pump job, Borland recommended using Permatex 98H/98D 80062/80063 High Tack Gasket Sealant on both sides of the water pump gasket. I did, in fact, do that, and also used it on the "extra gaskets" under the main water bridge to head gaskets (my car did in fact have those extra gaskets).

It seems to have worked well and it cleans up pretty easily (Permatex recommends lacquer thinner for removal; I've found that denatured alcohol works pretty well, too).

I'm just passing this one along; I'd be interested to hear what others have to say about this.