The Complete Engine Sealant Thread...

[Mark Henry]

It's different but comparable...I've never seen a 996 case leak with it. The big thing is it's a metered bead, you don't want too much, takes a steady hand laying the bead down.
I'd first see what the factory book says, for the 996 the manual spec specifically says Loctite SI 5900.

[outsider347]

Just about to order Henrys Case Sealant Kit.
Noticed that the D/C 55/111 is not included in the kit.

Is the DC 111 still the recommended O ring lube?
Suggestion where to purchase?


Apologies if the answer is somewhere in this thread...I couldn't find it
Tks Gents

[Cobalt]

AFAIK the Molykoat 111 is the same and readily available.

[KTL]

Dow 111 or 112 is available at McMaster Carr. 112 is the higher temperature version of 111 but really not absolutely necessary for the additional $5 per tube of goop.

[Robert59095]

I have (conceivably) a tip for guys that don't want their engine to leak oil. I bought a 12x14" granite surface plate and the Snap-On stud puller kit (great purchase!).

These are my "favorite" places for 911 engines to leak: chain case/case, chain case/cover, chain case cover, cam housings, valve covers, valve cover mating surface on heads, timing shaft cover plate, thermostat housing, mating surface for the t'stat housing, in other words, everywhere.

I spray glued (minimally) some 120 grit to the surface plate and had at it with all these surfaces (minus studs, of course). I left the case on the bench and held the surface plate in my hands and ground away, using circular motions. You would be amazed it what it took to take these down to flat. No wonder 911 engines are prone to leaking oil! All this was before I sent out me case for a good cleaning and lots of other work.

The sump area was too small for my surface plate. The machine shop will be flycutting that area. No grinding on the case halves. Now, if I use all the sealants described in this wonderful thread . . .

Hope this is useful!

- Rob

[Lapkritis]

Use krytox for o-ring lube.

Sent from my SM-T580 using Tapatalk

[Henry Schmidt]

Originally Posted by outsider347

Just about to order Henrys Case Sealant Kit.
Noticed that the D/C 55/111 is not included in the kit.

Is the DC 111 still the recommended O ring lube?
Suggestion where to purchase?


Apologies if the answer is somewhere in this thread...I couldn't find it
Tks Gents

A small container of Dow 55 is included in the case sealant kit.
Time tested and government approved for over 100 weapons systems for decades.
This is a 15 years old picture and some things in the kit have changed (Dow is packaged in a small plastic container and ThreeBond 1104 have been replaced with 1184) but the success of the sealing system remains stellar.

[rs-vic]

Hi Guys. Here's a heads up for Dirko users. It has been reformulated and is completely different from the old Dirko. The old Dirko was smooth and creamy and took at least a half an hour to skin over, allowing plenty of time to assemble an engine case. The new product is wetter, stickier and starts to skin over in 10 minutes just like most other RTV silicones. I am very disappointed!

New Dirko comes in an 81 g tube compared to the old stuff in a 70 g tube.

[Mark Henry]

Originally Posted by Cobalt

I appreciate the response. I don't recall seeing SI 5900 in the manuals but just at the tear down and inspection stage so sealants are a number of weeks out also depends on if we repair it as stock or update to the 01- hydraulic lifters and larger valves. We have most everything we need EBS can get me the rest.

So Loctite is superior to the (yamabond, hondbond, threebond) whatever you want to call it?

Thx

I'd call it not quite the same but comparable.
The trick I do with rubbing sealant into paper gaskets the SI 5900 is superior from a cleaning perspective.

[mike sampsel]

Wonderful compilation of great information here. It seems for those with less experience in assembly, lock tite 574 might be easier to use than threebond 1184. Forty five minutes until “sweat starts pouring” with 574 and only 20 minutes with 1184.

Seems 20 minutes is pushing it a bit and puts the pressure on the inexperienced.

[Trackrash]

Not sure if it was covered in this thread previously, but there has been some discussion about not using sealant on the main bearing supports. Disaster Strikes; What went wrong?

The Porsche repair manual is not clear on this. From the Carrera Manual.

[mikedsilva]

Originally Posted by Trackrash

Not sure if it was covered in this thread previously, but there has been some discussion about not using sealant on the main bearing supports. Disaster Strikes; What went wrong?

The Porsche repair manual is not clear on this. From the Carrera Manual.

True.. it says "mating surfaces"... and it seems that the bearing journals are indeed mating surfaces.
However, it makes sense that adding anything here, is going to potentially alter your bearing clearance.

[dfink]

If anyone cares 10 years now and hylomar is still keeping oil in the engine just fine.

[dannobee]

There might have been some confusion in the earlier manuals, but in the later manuals there is indeed a diagram outlining where to put the bead of sealer, and it's ONLY around the perimeter, along with a blow-up of the area around the rear main seal. NO sealer on the "thrust blocks," AKA main bearing supports.

[mike sampsel]

Which case half to apply sealant to, my lesson learned. I applied sealant to the 1,2,3 side (fewer studs in the way). While maneuvering the case half to install, my gloved hand grabbed the seam with sealant down by the oil pump. Did I take too much off? Nobody would know, because I foolishly pressed on and sealed the case without stopping and looking at the 574 spread.

As such, I’m going to redo now. So had I used the 4,5,6 side for laying down the case sealer (as I will in my redo) , this was unlikely to happen. If I was younger and did not have a tweaked thumb, I probably could have avoided the inadvertent gloved wipe of my seam. And with more experience, I could have stopped and looked the spread over too. Oh well ... whining does little good

As such, I wonder what to with the thin layer of three bond 1211 I spread in the saddle of number eight. I won’t touch the 4,5,6 side, guess I might put another thin coat on top of the other one?
Or should the 1211 three bond be removed and fresh applied?

[DRACO A5OG]

Oh my brother, I feel the pain.

As a wise elder, you know you need to remove all and start again. Just take care and do not over do the 1211, when I redid it I did notice allot more spreaded into the case then I really wanted so I just went OEM and only used 574 with out any concern of over flow into the case. So for me it was good thing I screwed up the first time.

Break a Leg Young Man :-)

[Henry Schmidt]

Originally Posted by dannobee

There might have been some confusion in the earlier manuals, but in the later manuals there is indeed a diagram outlining where to put the bead of sealer, and it's ONLY around the perimeter, along with a blow-up of the area around the rear main seal. NO sealer on the "thrust blocks," AKA main bearing supports.

The 574 is applied to the main web to improve shear not as a sealant.
You might be surprised at how much 574 reduces main web shuffle.

[Iciclehead]

Originally Posted by Henry Schmidt

The 574 is applied to the main web to improve shear not as a sealant.
You might be surprised at how much 574 reduces main web shuffle.

Now that is interesting...just curious how you were able to find out? It makes sense for sure compared to an Al to AL surface.

Dennis

[rdimarco]

To glue or not to glue the main webs? Some pros say yes, other pros say no. I typically interpret this as both ways will work when done properly. Reducing shuffle by using loctite 574 on the webs seems like a benefit. I wanted to reassure myself that I wasn't significantly changing bearing clearances with the 574.
So instead of gluing my case together and measuring bores, I glued & bolted together two gauge blocks (advertised as flat within .0002"). Measurements of the stacked blocks with and without the 574 were the same (same technique each time), down to .0001" resolution of my micrometer. The loctite was applied to one surface as thin as possible, I spread it with a gloved finger and wiped off all excess until just the thinnest possible layer possible remained on the surface.
I am not a machinist or an engineer, so I can't say if this is significant. Even if the clearance increased by .0001", I would not be bothered by it on my personal engine. I have no way to assess sheer resistance when bolted together. After 18hr cure time and unbolting the blocks it took 10 moderate blows with a rubber mallet to separate them. A small amount of the 574 on the surface was still uncured liquid and could be wiped off, most of it needed solvent to remove. There was no visible excess around the edges.
My pseudo-science exercise may not be applicable, but maybe by sharing an expert will further educate me

[Henry Schmidt]

Originally Posted by Iciclehead

Now that is interesting...just curious how you were able to find out? It makes sense for sure compared to an Al to AL surface.

Dennis

When building performance engines, quite often they are disassembled on a regular basis. Our experience is that you can see movement between cases. (main web shuffle) Stabilizing the case halves is the purpose of shuffle pins.
During my research on sealants, glues and thread lockers I came across a spec sheet that specifies test methods and shear values for LocTite 574. The numbers don't suggest a huge amount of shear improvement but there is enough for me to use this product in this application.
The benefit on mag cases seems greater than with aluminum.