Lubes, sealants and different approaches...
 

** updated with other opinions**

After reading Wayne's book and taking the engine rebuilding course with Jerry Woods I am now doing the preliminary planning for my rebuild of my 993 engine. An interesting part of the course was comparing what Gerry does as compared to Wayne's methods. I now have updated this thread so its a place were I can summarize what various builders have said they use in different threads on the list. MY appologies if I have misread or misquoted anyone.

Of course now I have to decide which one is my preferred choice!

Case Sealant
Wayne - Locktite 574
Jerry - Dow Corning 730
Henry - Threebond 1104 ;
John Walker - Erling Dirko

#8 Bearing
Wayne - Nothing
Jerry - Dow Corning 730
Henry - Threebond 1211 (aka "Yamabond") on #8
John Walker - a smear of elring dirko sealant in the bore where the #8 o-ring would contact

Copper Base Gaskets
Wayne - Locktite 574
Jerry - Dow Corning 730
Henry - Elring Curil-T (because of the movement) ; Threebond 1211 for the 964/993 base O-rings
John Walker - K&W Copper Coat

Bearing Journal Webs and through bolts
Wayne - Locktite 574
Jerry - Nothing
Henry - Locktite 574
John Walker - Nothing

Cam Towers
Wayne - Locktite 574
Jerry - Locktite 574
Henry - Threebond 1104
John Walker - Elring Dirko

Through Bolt o-rings
Wayne - Permatex Black Silicone
Jerry - Does not use any sealant but lubes the O rings

Gaskets
Wayne - no sure
Jerry - Nothing
Henry - Very thin coat of 574 (like a glaze)

O Ring Lube
Wayne - Not sure
Jerry - Dow Corning 111

Heavy thread locking
Wayne - Locktite Red 271
Jerry - Locktite Red 271

Light thread locking
Wayne - Not sure
Jerry - Locktite Blue 242

Shaft Seals
Wayne - Curil-T
Jerry - Claims its not needed

Assembly Lube
Wayne - Lubro Moly Engine Assembly Lube
Jerry - Torco MPZ

Gasket Solvent
Wayne - Not sure
Jerry - Dykem
xxxxx - MEK
Other - Permatex Gasker Remover good for 574.

Bearing Clearances
Wayne - Plastigauge
Jerry - Does not use Plastiguage because he only want to crush bearing shells once

Other notes and little tidbits from the course:

1 - Jerry thought the Curil-T was an older solution that was OK but he was suspicious of its mechanical characteristics in the long term. He does not like using a silicon seal type of material near or on an O ring since the O ring is designed to move.

2 - The Locktite 574 tends to go on too thick and then cases will leak. He has used the 730 for 28 years with no problems including many race cars (including LeMans). He likens the 730 product to "liquid viton".

3 - He uses a bead on the case half and does not spread the 730 out but lets the case to case pressure spread the product out.

4 - He does not recommend Platinum plugs for a Porsche '; they tend to wear and at times they could loose the tip. Bosch plugs are the best because of the metal they use for the body does not gall and appear not to lock themselves into the aluminium heads.

4 - Jerry's run in procedure is different because he has a dyno. For a home rebuild he does not recommend that the car run unloaded as the initial break-in even at a higher RPM. If the engine is in a car then

a - Start and run the engine for a minute at higher RPM to check for fuel and oil leaks. If all looks good then
b - Go for a 20-30 minute run-in with a light load such as a freeway drive, light throttle at 20-30 mph i.e. 1/2 hour with gas pressuring on the rings then
c - run 700 to 1000 miles then change oil, adjust valves.

When Jerry does a rebuild the engine is run on the dyno for a full hour under various loads before its installed in the car. He also does not recommend changing the oil after 20 minutes of running but changing it after the first 800 miles. Its a bit contradictory since disconnecting an engine from the dyno and installing it forces an oil change. ;-)

It is not necessary to retorque the heads but it certainly can be done to double check.

From my point of time I will dump the oil after the 20 minute first break-in and I also like the idea of going onto the road to give a sustained load.

Cheers,

Mike

WOW, Mike! Thanks for taking the time for the great write up! It's these different thought schools that makes me VERY nervous when I get ready to assemble my 930 engine! I'm just trying to gather the facts. Anyone else have some thoughts to share about this?

Hi sand_man,

I would not get nervous about it...they both have valid approaches and its interesting to see some differences. The idea is to take a combination that works for you. For instance after seeing the Dow Corning 730 its likely that I will use that stuff rather than the 574 ; its easier to apply and you don't have to worry so much about getting the coating exactly even. But just use your own judgement...in a lot of this stuff there is no one right answer.

Cheers,

Mike

Great information, Mike! I've noticed that Henry Schmidt hasn't weighed in yet. He uses some of the ThreeBond products on his assemblies and guarantees no leaks (when he does it). Here's a link to a good thread on the topic.

I thought I did a search for this stuff befor I posted...must of been fingeritis and I screwed up. That thread is great reading...thanks!

Another difference....Jerry does not put any sealant on the main bearing supports but only on the perimeter of the case. Maybe that is because of the nature of the 730.

The comment about the 730 is not easily removed is valid...Jerry confirmed that during the course that the stuff is hard to clean off and immune to almost all solvents.

Maybe there should just have a reference sheet on the site with all of this listed in some printable form...it would make life easier for use newbies...

Cheers,

Mike

In this thread Henry mentions that the 574 is used where there are gaskets...Henry could you be more specific? Does that include the chain-box to case interface, the troublesome chain-box cover, the cam backing plates. Which gaskets exactly. It's sort of been my experience and understanding, not to treat most gaskets with anything...however, I don't want ANY leaks this time!

Also, by applying 574 at the through bolts, do you mean the inner bearing saddles/webs? This too has gotten mixed opinions. Some say not to apply sealant inside because it screws up the bearing tolerances...others say that avoiding this area could cause the case to buckle a little. I'm by no means attempting to second guess anyone...I just want it to be right! I won't have the luxury of doing this again!

Cool stuff, thanks for putting up the differences. I have used the loctite 574 to seal cases and just ran a bead, I never smeared it around. Around the cylinder base gaskets I used an airplane engine sealant called permatex but only very lightly. So far no problems.

I remember in Ralph's writeup on his 3.5 build that Yamabond was mentioned as a case sealant. Never run across the stuff but he said his engine builder recommended it. At least that is what I remember.

Also, I dont think there is one way to do all this, everyone has their preference and plenty of reasons. A spreadsheet of all the different "big" and or well respected engine builders and their sealants and what not would be very interesting and provide plenty of fodder for constructive criticism.

I'm a big fan of Elmer's white glue for the case halves. For all the O-rings and gaskets - for continuity - I use Elmer's rubber cement. :rolleyes:

Porschekid962 said "big" builders, not "model" builders... :p

I guess my sarcasm meter is broken today...not understanding WTF your probelm is? But thanks for the useful information.

:D Just kiddin' around. Sorry if I upset you.

On the serious tip, Yamabond and 574 are what the factory recommends/uses and I find it hard to wrap my head around a reason why anyone would stray from that recommendation. Maybe the addition of a little Gray silicone for strainer plate gaskets and timing covers for added security.

On top of that you use the tougher Viton o-rings lubed with either motor oil or white grease and you'll have a dry motor. THE KEY to having a dry motor is that all your sealing surfaces are clean - i.e. case halves, timing cover/chain boxes, strainer plate (for early motors).

The reason these cars leak (in this case I'm referring to after a rebuild and not those that are high mileage and/or abused) is because people get lazy or are in a hurry and they don't take the TIME and CARE to CLEAN everything properly. That, or because the motors have been together and apart so many damn times that the sealing surfaces are worn out. In the latter case I recommend a lap and line bore (to get happy case halves) back to standard (unless you have a .10 under crank etc. etc.).

Key words for today's lesson: CARE, TIME, CLEAN

There, now that I've contributed to the thread, I just want to say that I stand behind my first recommendation of Elmer's White and Elmer's Rubber Cement. :p

No worries...I thought you were kidding, but the :rolleyes: threw me. And THANKS for the useful info in your updated response. I'm still thinking that the Elmer's suggestion might be a good idea! Save a few bucks and all...HAHAHA!

Very good memory!

Yamabond = 3 Bond 1104 = what Andial & PMNA use for case sealant.

It can also be used successfully for mating the head/cam tower assembly.:)

I agree, you'll get a ton of different options and every engine builder has their favorites.

Ralph

And the answer is...

All of them are correct. It works for them.

Although I followed Wayne's book for my 930 rebuild, I did not use anything on the copper cylinder base shims or on the bearing journal webs. The engine works and does not leak.

Okay...got my crank case split open early this morning, and was shocked to see that there was NO sealant between the case halves! I guess with all of this worry about what product to use, I thought for sure the factory must use a sealer of some sort. However, all I can see is just perfectly smooth and shiny surfaces! Can someone explain? I know that the case is a precision casting. I've also rebuilt too many aircooled VW engines to count and nearly all of them had a sealant of some sort between the case halves. I think I'm just gonna use a thin coat of 574 and call it a day! Seeing that there's nothing there from the factory, puts a different perspective on it for me.

Wow. Out of all those products listed, the only ones I used on my engine were the black silicone (case throughbolt o-rings), the DowCorning 111 grease on the return tube o-rings, and motor oil.
For all the other applications I used products i use in my shop on industrial pumps and turbines.

Funny thing is, after a year my engine does not leak a drop.

I too believe that the surface preparation and assembly are more important than the sealant.

I am wondering about comparative costs of these sealants. For example the Dow 730 is almost $80 for a small tube now. What does the Threebond 1104 run and Loctite 574 cost? Surely if all things are equal most reasonable people would take this into concideration?

Up here in the far north (Canada) a tube of 730 is about $75CDN (or $65US). A tube of 574 is about $23 on the Pelican store. So there is a price difference but when you are doing a $5K rebuild the $50 is not much if a product seals better. I now have an idea about some of the characteristics of each product but I still have not chosen any particular one. I have no idea about the cost of Threebond.

Mike,
Did you take pics in the class. I took some when I took the class a few years ago but lost them on my hard drive. Do you happen to have a pic of the Dow 730 when it is placed on the case? If you do could you post it. If I remember correctly, Jerry used Dow 730 and placed it on the case half that was installed on the stand (4-6 cyl - right case half) but in Wayne's book he mentions that 730 should be placed on the left case half. Or am I wrong and did Jerry put it on the left case. I do remember him making a point to make a wide arc around the oil relief hole on the case.

In Wayne's book he mentiones that 574 be applied to the right case half.