Only the engine builder would know that, but he did reseal the cylinder to case bores with Cural T as they were leaking from the bases also the first go around.

I pulled the upper valve covers off and found the rocker shafts are not leaking. But close inspection showed the head stud nuts are wet with hanging drips. I didn't check the lowers yet.
If the Supertec Headstuds weren't torqued to 30lbs as recommended but at 23.5 could this be exaggerating the leaking problem.

Yes, the studs have specific torque requirements.

after using hylomar for a while, I'm very impressed. has anyone used it to seal the case halves? seems it would be ideal. 574 didn't work for me, it was hardened by the time I got things torqued down. and 1104 scares me, I imagine bits of squeeze-out floating around inside my engine. any thoughts? Don.

Not an issue.

Kevin Jeanette at http://www.gunnarracing.com/ uses it on the case halves.
Most of his engines are for race cars so they may be coming apart after 50 hours but he used to use it on street car motors and he says he never had oil leaks.

It is the best all around gasket sealer in my opinion. Similar to curil T but better.
Harbor Freight tools even sells it for about $5 a tube here.

I've used it on all the 911 chain case gaskets and o-rings and many other things including mechanical fuel pumps over the years. Gas doesn't touch it.
Works well on the cork oil tank sending unit gasket too.
It never hardens, always stays gooey and cleans up really easy with laquer thinner on a rag.

I've heard that Rolls Royce invented it for the P51 mustang V12 merlin engines.

Here's the stuff they sell @ harbor freight around here. It says made in UK on the backhttp://forums.pelicanparts.com/uploa...1225739505.jpg

Have been doing some research on hylomar and found that you might have to retorque after using it. It was suggested for loaded studs to torque wait a few minutes and then retorque. It was also suggested to put it on both halves, let the volitiles evaporate then assemble. Since it is non setting it appears there is no hurry to set the case halves.
Found a few VW forums and sounds like they have been using it with good success. I have found several instances of loctite 574 failing. Hence the reason for researching alternatives. The engine I just built was free of debris, cleaned with rubbing alcohol and had good sqeeze out of the 574. It leaked from the moment I put oil in it. Upon dissasembly the coating looked OK but there were several places where it just didn't adhere. If I didn't know the case was clean and saw someone elses leak, I would say you didn't get the case clean but I know it was.
The hylomar also appears to offer easy removal if the case does need to be re-split. They say just wipe it off with laquer thinner no scraping required.

Regarding the Hylomar, I've acquired my tube (same stuff that hand, pictured above is holding) and will be using it on many of the gaskets that were previously lightly coated with 574...as described earlier in this thread.

I'm up to almost 17,000 daily driven miles and while I'm not leaking any oil on my floor, a few gaskets have started to appear a tad saturated with oil, and are close to weeping. I'm pulling my engine to upgrade some clutch components, so this will be a "while I'm in there". So I'll be redoing the chain box to engine case gaskets, the chain cover gaskets, and the cam backing plate gaskets...all to be new and coated with Hylomar. Oh well, I guess I needed an excuse to practice cam timing, again!

Sand_Man - Did you apply the hylomar to both sides of the case or did you use the 574 on the case and now plan to use the hylomar in the repair

I used the Threebond 1104 on my case halves...no issues there. A thin coat of 574 was used on many of the paper-like gaskets. Most are holding up fine, it's just the cam box areas that are in need of attention. It's nothing dramatic yet, but I know it's only a matter of time before the drops start. So these are the areas that I'll be using the Hylomar on.

I'll also be coating the o-rings that are used on the cam backing plates with Hylomar.

Hylomar never dries completely (non- setting) which makes it inappropriate for long term case sealing. If used as a case sealer, you might get lucky but it's a lot of work to reseal a case so hoping to get lucky seems vacuous to me.
For racing or sport engine that are disassembled on a regular basis it is fine.
The product is basically the same consistency as Curil T and should only be used in similar applications.

In the case of weeping chain box gaskets that had 574 thinly applied a simple retorque may cure your weeping issues.
Cheers

As usual, Henry, thanks for the expert advice. I'm inclined to agree about the use of Hylomar for actually sealing an engine case...probably a non-issue for a serious race engine with regular tear downs. I dunno, I don't have enough experience, so what the hell do I know? Sealing the case was something I just couldn't roll the dice on.

Threebond 1104 was great to work with. 574 used as Henry recommended. Didn't feel rushed and had a very small bead around the case. No leaks after three years.

http://forums.pelicanparts.com/uploa...1227303727.jpg

My right side chain box is weeping a bit. Started at around 600 miles after the rebuild.

I plan on dropping the engine again in January to address a minor weep from my oil cooler. While it is out, I'd like to fix the chain box gasket.

Is it common to use sealants in conjunction with the paper gaskets? If so, what is best and is it applied to both sides of the paper gasket?

I don't know if it's common to use a sealant, but I put a very thin film of CurilT on both sides of the paper gaskets and they've held up very well over the years with zero weepage.

Thanks, I have lots of that CurilT left over too.

I was just browsing through old photos of the engine. It clearly had weeping in the same area as it does now. Could be a small flaw in the mating surfaces. I will give the CurilT a go.

Maybe it was due to uneven torquing of the covers to the studs?

Could be. But I was pretty particular, slow, and methodical. I may just try to snug em up a tad.

If you have a straightedge or milled surface, check the base of flange in relation with the overall mating surface of the cover. It might have been over torqued in the past.