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.

Still going to try the hylomar. I guess I don't see why just because it doesn't get hard it is bad. Many others appear to use it with great success. Has anyone tried it and had it wash out or is it just tradition to keep on using the anaerobics. I think the fact that it stays pliable would be a bonus so if needed the case could be retorqued. I guess if you can seal a case with 574 or 1194 then good stick with what works. Didn't work for me so going to try something else. If the case leaks I will take it down again.
Also just a side note on the blue o-rings used on the through bolts. That is about the only place that didn't leak. Had no problems with them and in fact everyone of them but two came back off in tack. Why... I believe it was the archer professional gell lubricant with teflon that I used to assemble. It also made the return tubes slide in so easy that I thought something was wrong. Even the generally stuborn cam shaft o-rings just slid right into place. No leaks on any of those areas.

I used Dow Corning 111 on the camshaft O-ring seals, oil return tube O-rings, oil cooler seals, etc. On the cam box and cover gaskets, paper cam gaskets and other gaskets, I used a thin smear of Hylomar. No leaks so far. I also used Hylomar on the cylinder base gaskets. I used Dow Corning 111 to help slip the RSR seals on the rocker shafts, too.

I very much like the ease of disassembly and possible gasket re-usability of the non-hardening sealants like Hylomar and Curil-T.

Brian

As inexpensive as gaskets are, I don't think I'd ever reuse one...

Perhaps not, but if I'm on the side of the road ...

Brian

Me too...

There was another older thread that talked about Loctite 518 replacing 573/574 - something Warren had recommended. According to the 518 data sheet, as it ages, it increases its resistance to oil, whereas 573/574 decrease their resistance. Lap shear strength compares favorably too. 518 Data sheet is here:

https://tds.us.henkel.com//NA/UT/HNAUTTDS.nsf/web/AACE3993B0D66F88882571870000D7DE/$File/518-EN.pdf

574 Data Sheet:

https://tds.us.henkel.com//NA/UT/HNAUTTDS.nsf/web/AACE3993B0D66F88882571870000D7DE/$File/574-EN.pdf

JB

The loctite 574 is probably great if the case seals and you never have to take it apart again. Even it it seals you could have to take it apart for other reasons. If you do have to take it apart beware to place lots of time aside for cleanup. The 574 is like friggin super rock. Regardless of what it says even the squeeze out gets hard. The heads were the worst because of all the studs and the springs that you have to go around. I literally had to take a awl and chisle some of the stuff off. I sure hope the hylomar works because I don't want to ever go back to using the anaerobic sealants. Perhaps it is just the 574. I used a peratex sealant on my last engine and I don't remember having the cleanup problem that I had with the 574. Perhaps the threebond is better also.

Use paint stripper. I will remove 95% on first clean-up.

The best thing for removing old 574 is new 574. If you plan on using it again you don't have to completely remove all of it. The new stuff will melt the old stuff and it will cure again.

I like Threebond 1194 for the case perimeter but Loctite 574 is still my favorite for sealing the cam housings to the heads.

I also had a nightmare trying to get off all the old 574 after this.....
http://forums.pelicanparts.com/911-engine-rebuilding-forum/440022-bottom-end-together-again.html
the re-melting thing wouldn't work as there was too much thickness. I'll be using hylomar practically everywhere I can. anyone wanna buy an unopened tube of threebond 1211? I had to rebuild this engine because some genius used silicone to seal the case halves.
http://forums.pelicanparts.com/porsche-911-technical-forum/371960-well-rod-knock-no-longer-mystery.html?highlight=silicone
the bits plugged most oil passages, and finally a rod bearing started knocking. good thing, anything else would have caused more damage! even with the threebond 1194 I have concerns over the squeeze-out on the inside getting into something it shouldn't. with hylomar, that just is NOT AN ISSUE! I'll use it everywhere I can, and if it does somehow start leaking somewhere. I can console myself in the knowledge that I won't be digging chunks of gunk out of the oil passages next time I tear it down.

*** HAS THE FIRST PAGE BEEN UPDATED ALREADY I.E. ACCURATE AS OF TODAY ?????????
IF NOT, PLEASE REPLY ORIGINAL POSTER AS I BELIEVE YOU ARE THE ONLY ONE ABLE TO EDIT !!!
Thank you, Bob
ps is the list missing any area(s) that need attention or mentioning what to do OR not to do ??

It is still current.

I agree with your theory.

I have used Hylomar for about 10 years (on F-15/16 engines) and I dont think I would use it on 911 case halves.

We use it a lot on the engines but they leak like crazy, plus, constant retorquing is required as it acts squishy under the bolt heads.

In general, anywhere Hylomar is applied usually results in oil leakage. :)

Hylomar is working well so far. Not a super lot of miles but nearly 30 dyno pulls and few road trips. It has been togeather now for at least a month. No leaks at all that I can tell. Much better results for me anyhow than the 574 which leaked as soon as oil was put in.I may have done it wrong but there were two of us one with the book checking to make sure the other got all the bolts in and torqued.

Chainboxes with 574 will not retorque easily. The 574 will be in there like rock. If you tighten enough to stop a leak you proably just pressed the 574 into the gasket which will eventually just make things worse. If you didn't use a gasket well thats another story.......

I used it and it hasn't leaked. Pretty sure that if I had been using it for 10 years and still couldn't get it to work I would be using something else by now. ;) How much does an F-16 cost these days.

I agree, using a hardening sealer anywhere a paper gasket is used is unnecessary. Why make more work for yourself when the engine is disassembled in the future? Use Curil-T, Hylomar or any other non-hardening sealer recommended on this thread.
Hope everyone had a safe and enjoyable New Year's.

In the aviation world, you have to use what is called out by the tech data - no deviation is allowed.

F-15/16's engines run I believe around $2 mil new.

Yeah, but how many run-time hours between teardowns? :D

Isn't this fun.
Hylomar is not the new "miracle glue". It was a recommended product back in the days when I worked on RollsRoyse engines. We tried it on 911 engine 25 years ago and it proved "inappropriate for long term case sealing." You'll also find it lacking for sealing cam tower to heads. These pieces are rarely flat. I didn't post this information with an ulterior motive, I don't "hate" Hylomar. The purpose of this thread is to provide information that will lead to the greatest likelihood of success.
Trial and error is the best teacher, so experiment away and learn as you go.
Good luck
Cheers

Well said Henry, and that is indeed the crux of this thread; as foolproof a way as possible to seal our engines. I don''t plan on building another for some time, and didn't want to experiment on my rebuild last year.

Anybody know what the Loctite 9340 Hysol in Henry's kit was used for?
And what is that grey piece in the central left of the picture?