Really great to see this thread continually updated with all of the data points and experiences. At some point (hopefully a long way out), I'm sure I'll be pulling the 993 engine to have the valve guides done (top end) and I'm sure to refer back to this thread for guidance...

What size tubes of threebond 1184 (1104,1194) and threebond 1215 (1211) are needed. I'm seeing a few different sizes listed on the various sites.
thanks.

3.5 oz tube should be plenty with some left over. Get a couple tubes and have some extra around in case you need or want to redo something.

Does anyone know the difference beetween Threebond 1104 and 1104 Neo?
I can't seem to find much info regarding Threebond products.

Edit: After asking Three Bond about this, they say that 1104 Neo is the same product, made in Malaysia. 1184 is the US replacement for 1104.

NEW LIST (I've lost the ability to Edit Post #1 since it is from 2008...)

Outer Case Halves: Threebond 1104 (now 1184)

Bearing Saddle Surfaces: Loctite 574

#8 Bearing (balancer end) O-Ring: Threebond 1211 (now 1215)

Case Thru Bolts: Dow Corning 111 on Green Viton O-Rings

Flywheel Seal: DRY

Balancer Seal: DRY

Intermediate Shaft Cover to Case: ThreeBond 1211 (now 1215)

Oil Breather Cover to Case: ThreeBond 1211 (now 1215)

Cylinders to Case: Curil K-2 or ThreeBond 1211 (now 1215)

Cam Towers to Cylinder Heads: Threebond 1104 (now 1184)

Cam Chain Housings to Case: Threebond 1104 (now 1184)

Cam Chain Housings to Cam Towers: Threebond 1104 (now 1184)

Cam Chain Housing Cover to Cam Chain Housing: Threebond 1104 (now 1184)

Gaskets: Thin coat of Loctite 574

Thanks a lot folks, I really appreciate the feedback!

EDIT: Most Popular solutions for sealing added to each item above to include superseded items.

:cool:

As a professional Porsche engine builder with 30 years experience and over 400 total builts, I can attest to the consistency of this process.
Although many builders find the LocTite on the main bearing saddles to be unnecessary, we find that it adds a definite shear strength at the case joint. This shear strength helps prevent case shuffle. (Not as well as shuffle pins but better than no adhesive at all.
The Dow O-ring lubricant (55 or 111) does exactly what it was/is designed to do. It lubricates the o-ring preventing tears during installation and after the engine/ sealing surface reaches operating temperature, there is a chemical reaction that swells the o-ring filling any void around the sealing surfaces.
The o-ring during operation is constantly in compression, never tension.

Improve the breed. Advance. Choose a ring lube that doesn't degrade your seals.

There is ZERO evidence that Dow 55 O-ring lubricant "degrades" o-rings in any meaningful way. Change does not equate to "degrade" and in fact, I would argue from experience that "seal swell" is a positive innovation in this application.
In fact, the military calls out Dow 55 for use on an incredible number of weapons systems both vintage and modern day.

I have seen no documented cases of o-ring failure do to Dow 55.

In the interest of improvement, if anyone has documented evidence that Dow 55 has caused an o-ring failure, I would be interested in that evidence.

Same old dance Henry. Welcome back...

http://i458.photobucket.com/albums/q...ps13839b78.jpg

Graphs and charts are very impressive. The Global Warming community can attest to that (flame suit on). I am not taking sides on this topic that refuses to go away, but before anyone has the final word, I, for one, would like to see the test criteria and environment that produced the results above.

(No tone implied here) So which one to use? None? What's your recommendation?

Dupont Krytox. More spendy but there's a reason.

The use of the diagram I've shared above is for educational purposes only.

The original diagram before mark-up for education is from Dow Corning Corporation and is copyrighted.

Form No. 10-773B-01 AGP4616
Here's a link to the PDF document:

http://www.calo.co.kr/pdf/download.php?id=yg_sg_dc-55M

The test conditions as specified in the title of the document are under ASTM D412, which is updated periodically:

ASTM D412 - 06a(2013) Standard Test Methods for Vulcanized Rubber and Thermoplastic Elastomers—Tension

With most things in the physical world, there are compromises.
Engine building is no different.
We give up compression for driveability and we sacrifice weight for cost. We sacrifice horse power for torque.
The question is always "what is the trade off?"
In the graph above (from Dow research BTW.) you see only one criteria.
During the development of Dow 55, the engineers set the criteria on multiple levels.
They wanted to enhance the sealing properties as well as enhancing the life of an given o-ring while providing lubricant for installation.
To these ends, they decided (correctly I believe) to enhance the sealing properties by expanding the o-ring after installation.
They were also interested in enhancing crush resistance of a given o-ring over time and heat cycles.
They accomplish these goal by slightly changing the o-ring with a propitiatory chemical formula.
This chemical change in no way degrades the o-ring in a way that causes it to deteriorate. Much to the contrary, we have found over years that the o-rings seem more elastic after long periods with the Dow55 than without.

To my knowledge, no other lubricant offers these properties.

If we were, let's say building a slingshot we would probably choose a different treatment for the elastic material but I guess if I were building a sling shot I might solicit the advise of Dennis the Menace for his anecdotal expertise.

Henry, what would you describe the relationship between the o-ring and the threads on the through-bolt as? Do you compress a tomato with a knife?

After installation, the relationship between o-ring and threads is a non-issue. I have never seen a leaking case o-ring precipitated by cuts (your knife analogy) from case bolt threads. I have seen leaking precipitated by seal hardening and sealing surface degradation (mostly mag cases). Even with case degradation, we see good sealing with the Dow 55.

Truth be told, after the first couple of hours of engine life, you rarely see case o-rings leak no matter what lubricant is used. Most leaks are caused by poor installation techniques. We just like the insurance offered by using Dow 55.

Have you considered there are better options out there? This is what I believe I'm presenting to you and others with the alternative Dupont Krytox. I understand you love the DC55 and you're spinning the lost of strength as a positive now that you're aware of it... but there are options that don't cause that drop in strength. That's insurance Dow 55 doesn't offer.

Haven't we had this little discussion a few times? How about if you professionally agree to disagree rather than have a neurotic conversation and damage an otherwise very valuable thread.

Us mere mortals will pick one side or another and just go with it....personally I am a Dow guy but I only have two engineers in the family so my sample size is small...

Dennis

Indeed we have but it's important to consider the ramifications. If you use Henry's suggestion of DC55 without chamfering/beveling your case holes then you're effectively mixing gasoline with fire. It's a reckless suggestion to not include the machining/beveling requirement next to the grease due to the profound negative effects on the Viton. Not everyone plans on beveling their case halves when tackling the job and if they're shopping for the quick data point of which grease to use when assembling (purpose of this thread) then they could be making a BIG mistake. DC55, as accepted and proven countless times on this forum now, reduces tensile strength (which corresponds to tear resistance) of Viton by nearly half. Will his suggestion of DC55 work as long as you've beveled both halves? The answer is yes, for awhile although it will likely shred on the bolt thread. Henry's answer is also that you must bevel everything. Why play games though? There are alternative greases available that don't pose the same risk. Educated consumers can choose more wisely knowing this information.