574 sealer on cam holder/tower to head

[mike sampsel]

So I think I’ve got adequate coverage on my cam holder.
Anyone else? Should I circle all the bolts/studs?

[MBruns]

you have way more than you need, smear what you have around the holes and remove a little if you can, yes it will squeeze out but not needed
Mike Bruns

[Mark Henry]

Agree, you only need a real thin coat.

[Iciclehead]

OK, the thin coat makes sense, but I was wondering if it also made sense to smooth out that surface like other surfaces can be smoothed....fine grit sandpaper glued to a glass or marble block.

Too dangerous or will it help with the use of a very thin coat of 574?

Dennis

[bpu699]

I thought hondabond was preffered here from the ultimate sealant thread?

[Flat6pac]

Hondabond has to be applied to both surfaces to work properly
Just on one surface, it cures off too fast so it’s only leakproof on one side.
Read directions on the tube
Bruce

[Jeff Alton]

Hondabond/Yamabond/Threebond (all made by threebond) is a great sealant. It is too time consuming to apply to both sides despite what the directions say. It sets up quickly. We seal every case with Threebond and only apply to one side, and have never ever had a leak.

Cheers

[Mark Henry]

I agree, if you you use threebond you only do one side, another reason is because it sets up so quick doing both sides the sealant will be too thick.
Clients want pic's of their builds, but one thing I can't do is sealants, because I don't have the time.

One thing I don't like about threebond is clean up, if you mess up and have take it apart it's a real PITA to get the sealant back off.

[mike sampsel]

Thanks for the replies all. Picture is prior to getting my finger in the 574 and smoothing and moving some off to bare spots. It squeezed out in all the recesses where the valve springs reside.

Maybe I used a bit too much 574? More worried about a blank spot I guess.
Can using too much 574 cause leaks? Seems if torqued well it should smooth out.

I used the threebond (1211) recommended for number 8. Thought about girko, and threebond as well for the case. As a one and done first timer I was nervous about fast setup times on threebond and yamabond too. Getting it all done solo (case closure) takes time even with best laid plans (Murphy’s law).

Anyway, it’s an honor to get the thoughtful comments. Once I knew the outer studs needed no 574, I proceeded without seeing the advice to remove some 574.

Cheers,

Mike

[bpu699]

Originally Posted by Jeff Alton

Hondabond/Yamabond/Threebond (all made by threebond) is a great sealant. It is too time consuming to apply to both sides despite what the directions say. It sets up quickly. We seal every case with Threebond and only apply to one side, and have never ever had a leak.

Cheers

Supertec’s kit includes the three bond for the case and this application...

Suppose either way works...

[safe]

Originally Posted by mike sampsel

So I think I’ve got adequate coverage on my cam holder.
Anyone else? Should I circle all the bolts/studs?

Apart from being to much, I would have cleaned up the old gunk.

[Walt Fricke]

Magnus
Knocking off hard ridges where too much sealant squished out and made lumps is a good idea. However, where the sealant sealed, new sealant (574) will soften it. The Porsche shop manual says so, anyway. So I never waste time carefully cleaning off all the old thin film. And I have never had a leak from these joints, or the case joints (don't ask me about main seals or rocker shafts). If I used something other than 574 I might go about things differently.

Lots of people like other sealants, but 574 works. You pick your poison. The ultimate sealant discussion has lots of useful information, but it isn't a source of what you absolutely must do or you will get leaks if you don't do it just this one way.

It is useful to give some individual thought to this. For instance, Mike S ran a line of sealant across the middle under the cam, from side to side. Well, why? No oil gets there, at least none to be prevented from going somewhere else. This is a sealant, not a glue. But you will see illustrations showing this - Wayne's fine book shows this, plus between the three pairs where the surfaces don't even touch. He's a fine engineer, and knows a lot more than most of us (certainly than me), but deity he isn't - he didn't think that one through.

And, as Mike B noted, you ought to circle all the stud holes. That way oil which might get past from the inside will be stopped by the outer sealant.

All the authorities talk of a thin coat. Anderson, and the shop manual, suggest using one of those really small (couple of inches) paint rollers. Works great, but only if you have been sparing of the orange stuff to start with - a little will spread quite far. But I've generally just run a thin bead around the big holes, with loops around the stud holes joining it. Minimal amount squished out, less work, especially if I can't find where I put the small roller. When eventually I pull things apart, you can see the whole surface was covered and sealed.

[mike sampsel]

Circle those studs where there is no oil, in case the seal job where there is oil, fails to seal. Hum. I did this at least some to smooth out (thin) the bead anyway, but it’s not needed if the rest seals good and was clean, clean, clean, clean and clean which it was.

I assume the remaining gunk is from OEM squeeze out in ‘78.. It is lower than the bridge and the head surface touches the bridge anyway, which Walt claims needs no 574. “Make work” cleaning it and was very hard stuff!

Walt:
So why can’t some safety sealant help on the bridge too?. I mean you say put it around the studs so if the seal where the oil is (around the valve recess) fails, it seems oil could leak out on the bridge just as the studs?

[Walt Fricke]

Mike
Because the surface area between the valve area (oil) and the studs is kind of thin, compared to where you will have sealant between the studs. Nothing like that applies between intake and exhaust - by circling those two studs you have added suspenders to your belt.

The "squeeze a thin bead" approach also means you can apply the sealant directly to the head, around the studs. A bit less chance of inadvertently wiping off sealant if you apply it to the cam carrier on your bench, and then maneuver the carrier onto the heads and studs. Though if you apply it to the carrier you can use the little roller to get it all distributed.

As you can see, applying sealant where two surfaces don't touch is really not helpful for any purpose, though you didn't do that.

I suspect if you have (or had) just put things together before sending pictures in for comment, all would be well. You'd have wiped off a lot of squeezed out sealant, which you wasted. But you may never do this again, so no matter.

[mike sampsel]

Thanks Walt,

Yes, I did assemble prior to getting comment on the forum as a little birdy told me via another media the plan was okay. And getting to the forum after I got my finger in the 574 was a challenge (I need to train Alexa I guess )

Interesting to note on my cam/housing there was remnants of 574 sealant on the bridge. Maybe the shop in 78 used some there or it drifted.

photo of the uncleaned housing below:

['78 SC]

This is how the heads and cam towers looked when I tore down my 1978 for the first time (broken head studs) in 2004 @ 31K miles. To be clear, this is how it came from the factory.

Despite the generous application of sealant ( Locktite 574, right?), the mating surfaces appear to have very thin coverage.

Apologies for the crappy photos, but this was pre-iPhone.