Sealing the case (or tomb)

From pcarworkshop

This article is about sealing the case halfs. This part is not that difficult but it helps if you are very anal and like to go at it step by step.

Here is a picture of our 993 oil pump...its a thing of beauty. It has two stages, one for the high pressure oil fed to the bearings etc. and the other to pickup the foamy oil from the case back to the tank. This end is the pickup end of the pump...that is why the cavity is so large. My pump was in great shape with no wear that I could see. I lubed up the pump with assembly paste anyways....

Putting assembly lub on the main bearings...carefull not to get any dust or particles in since that could easily scratch a bearing.....

I put some Curil-T on the main seal by the clutch for insurance. i also put some on the #8 - large bearing as well. Curil-T is wierd stuff...its does not cure and remains pliable so its flexible and provides a good seal. Besides that the green color is kindof cool!

Ok, oil pump is in, chains are in, crank and rods are in, supports for the rods are in and the case is getting prepared for sealing. Notice how bit the oil intake filter is that rests at the bottom of the case...mine was really clean so no debris was in the case before I ripped it apart for no reason...

Testing the backlash between the layshaft and the crank is important. If these two gears are too tight they could bind and cause all kinds of havoc. If they are too loose they could cause cam timing errors since the cam chains are run off the shaft. My reading was right in the middle of the spec...good stuff!

Here is the fixed end of a through bolt. These bolts hold the main bearing webs together and have to be sealed at each end for oil leaks. The O rings provide the oil seal...but how to we get them on without having them shred on the threads.....??

Well, its either a $100 tool from Porsche or the top of my felt marker...lettme see, hmmmmmm, I will use the felt marker! I had to drill it out a bit because it was too tight but it worked like a charm!

Ah tools of the trade. The 1104 is a very good case sealant which I used instead of the factory locktite...it has better sealing capabilities. The Curil-T I used for various spots that required a flexable seam and the Locktite 574 is the factory case sealant. I still used this sealant on the bearing webs....

Here I am spreading out a thin layer of the 1104 on the case perimeter. if you look closely you can see some orange goo on the main bearing webs...that is the Titebond 574. Its wierd stuff since it only drys when its out of contact with the air...like when pressed between to pieces of metal.

The tomb is being shut off again for several years (I hope). This is an interesting part since you are racing with time...the glues do setup and the whole operation once the case halfs touch is about 45 minutes or less...

Now the cases are touching each other (with the help of a rubber mallet) the through bolts have to be installed. The O ring has to be placed past the threads or they will be shredded and leak like crazy so out comes my trusty felt pen cap..

Once the O ring is in hold it down with two plastic shafts while the pen cap is pulled off......yank!

If you look carefully you can see the O ring in the right position..

The retainer which presses down on the O ring is next and then the final nut..repeat 11 times

Going through the torquing sequences...it takes two people since you can't let the through bolt twist since that might tear up the O ring again...so my buddy is holding the other end still while I torque up the main bearings. At this time the perimeter nuts and bolts have been lightly torqued. They will be finally torqued after the main bearings are done.

Its starting to look like a block again...notice the brand new perimeter nuts!

A bit of squeeze out from the Titbond 1104...just perfect!

Its starting to look like an engine again...with the new sprockets, new chains, etc.

Links to Rebuild Tour

1. Getting started, dropping the engine and superficial stripdown
2. Checking the default timing and Cams
3. Looking at the heads and the SAI passages
4. Valve guides, valves and carbon
5. Further Dissassembly
6. Exploring the SAI passages
7. Cleaning and getting ready to put it all together again
8. Rods and last minute checks before putting the case together
9. Sealing the case (or tomb)
10. Putting the pistons/cylinders back
11. Camshaft timing Part I
12. Camshaft timing Part II
13. Messing up a clean looking engine
14. Not quite there
15. Cranking it up