Sealing Case "Experiment" (so YOU don't have to!)

[cab83_750]

Henry,

Very well stated! A reminder to everyone that 'progress should never stop' is always welcome!

[anthony 911]

so put glue on the mains or not?

[Eagledriver]

You get to make that decision. It's your motor. Read all the opinions and make your choice.

-Andy

[cab83_750]

OK,

For a typical engine (such as an SC), what quantity do I need to completely seal my engine?

How many oz. (tubes) do I need for the following using Henry's method:

1. Threebond 1104
2. Threebond 1211
3. DowCorning 111
4. Curil T
5. LocTite 574

Thanks.

[JWPATE]

One tube of each.

[HKZ Bob]

Hello Folks,
have you never thought about using Loctide 5900 for case sealing.


Gaskets - what sealant to use?

[HKZ Bob]

[MBEngineering]

HI. No disrespect to any one building engines with whatever sealant you choose, and as Henry says the next engine should be better than the last one, and on that word I have over the years changed sealant quite a few times in various areas on the engine and the latest one's I am using is Porsche's 00 043 300 86 which is your Permatex (81160,26BR) or the VW AMV 188 200 03, which is a gray sealer, I have had good results with both sealers and no oil leaks.One last thing, I do not put any sealant on the main bearing webs.

regards mike

[1972_911T]

Ive just been examining my case halves to work out how im going to clean my oil passageways before I start re assembling my engine and ive noticed something about the 574 sealer. In my previous post I posted some pics that shows harded 574 in the through bolt holes, however ive just noticed all the holes with harded sealer in them are all but one of them on the bottom row which on closed examination dont appear to have oil running through them as there is no oil passage ways leading to them. The only one on the bottom row that does have a passage way is the one that supplies oil to the intermediate shaft bearing and this is totally free of any signs of sealer as are all the top through bolt holes that supply oil to the bearings. With the extent to which I overdid the application of 574 on my first rebuild I think its fair to say Henry is spot on with what he says about 574 been completely washed away by the oil.

Steve

[PeteKz]

Late addition:
Since this thread was referenced today, here is some additional information about the properties of 574. Although 574, Loctite thread lockers, and other anaerobic sealants require absence of air to cure, they also require close contact with metal to catalyze. If absence of air was the only requirement, then it would cure between plastic surfaces (or even in the tube it comes in). That does not happen.

I reviewed several technical sources about anaerobic sealants and queried Chat GPT:

--------------------
How Loctite 574 Cures:

Loctite 574 is an anaerobic flange sealant. It cures when oxygen is absent and the product is in contact with active metal ions (iron, steel, aluminum, cast iron).


To cure correctly, it needs:

A very thin bond line (typically 0.004–0.010 inches / 0.1–0.25 mm)
Two metal surfaces pressed together
Anaerobic environment (no air between flanges)

❌

It will NOT cure correctly if:

The gap between parts is too large
Only one side touches metal
Excess sealant is exposed to air
Parts are not clamped tightly

In large gaps, Loctite 574 often stays soft or gummy, because anaerobic sealants need metal + confinement to polymerize.

✔️

Best Use Cases:

Loctite 574 is ideal for:

Engine case halves (Porsche, VW, motorcycle engines)
Rigid machined flanges
Aluminum or cast-iron housings
Gearbox mating surfaces

This is why it’s widely used on Porsche engine case splits — the surfaces are machined to very tight tolerances.

⚠️ If Your Gap Is Too Large…

Use a different sealant, such as:

Loctite 518 (tolerates slightly larger gaps – up to ~0.5 mm)
ThreeBond 1184 or Yamabond 4
Curil T / Dirko HT (for flexible joints)

�� Bottom Line

Yes. Loctite 574 requires tight metal-to-metal contact and a thin bond line to cure.

If the gap is too large or uneven, it will not cure properly.

-----------------

Henry correctly questions how the cam oil pipes got clogged by it. It will not cure while circulating in the oil, and it will be so diluted that it cannot cure later. If the oil pipe really was clogged by cured 574--not something else that looked similar--the open questions remain, where it came from and how it got loose from wherever it cured. I don't have any further hypotheses.

[Henry Schmidt]

Originally Posted by cab83_750

OK,

For a typical engine (such as an SC), what quantity do I need to completely seal my engine?

How many oz. (tubes) do I need for the following using Henry's method:

1. Threebond 1104
2. Threebond 1211
3. DowCorning 111
4. Curil T
5. LocTite 574

Thanks.

For the amateur builder your success rate is greatly improved using Dirko HT or TB1184 than Loctite 574 on the case halves.

Our kit consists of:
Dirko Grey HT or ThreeBond 1184
ThreeBond 1211
One oz container of Dow 55
Loctite 574
Loctite Hysol EA 9340 epoxy-patch
Curil T2
And a set of green Viton case through bolt o-rings.

$200+ worth of product available from our host for the low price of $ 129.00. Simple use suggestions included.



https://www.pelicanparts.com/More_Info/SPTCSUPCSK001.htm?pn=SPTC-SUP-CSK-001&bc=c&SVSVSI=0653

[gsxrken]

I used Henry’s head studs and sealant kit above for my 2020 rebuild and still have no leaks 5 seasons later. I cannot stand to do things twice (unreasonably, clinically irrationally so) so I’m extremely grateful I’m still high and dry. Thanks Henry.