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It seems I have a oil leak on two of the head bolts where they go into the casing on the right side. I looked through the assembly manual and can't find anything about if there is any Permatex put on these bolts.
So, is there supposed to be any on these bolts when assembled. I hope so as I can remove the bolt and put some on and hopefully stop the leak.

Thanks, John

I could be wrong but I thought the head bolts didn't go through the case. I thought they were blind holes or are you talking about a leak on the head side and not the case side of the bolts?

Keith
#554

The leaks are definitely on the case side. Enough so I get drips on the exhaust.

John

I had oil coming from one of the studs on the number 3 cylinder. I put some yamabond around it which has stopped it for now.

Mine is also on #3 cyl. Going to try what you did Mike, thanks
John

See my post dated 1/5/16 concerning the possibility of oil leakage coming from the cylinder/head hold down studs where they thread into the case halves. All the threaded inserts in my case halves are not blind and are wide open to the case half interior. After much thought and discussion I elected to use permatex on the threads and threaded the studs down to where I could barely feel them using my finger on the inside of my case halves, being very careful that they did not extend into the case half interior. They all took approx 12 full rotations each. My engine is all together and has not been started yet and I am very curious to see if I do get oil leaks around the studs when I do.
An added note is that a friend of mine who builds v-dub engines for road use has shown me in his stacks of used case halves that some do indeed have blind inserts and some do not.
Surfly

(An added note is that a friend of mine who builds v-dub engines for road use has shown me in his stacks of used case halves that some do indeed have blind inserts and some do not.)

That's interesting, who would have guessed?
John

I have not used any sealer on any of the engines I've built, and I haven't had any head studs leak (yet). If you are going to put sealer on them, make sure to use something that's not going to glue the rods in so that they can't be removed. I'd suggest using something like Fuel Lube. It's a great thread sealer and stays soft for easy removal later.

If you are going to put sealer on them, make sure to use something that's not going to glue the rods in so that they can't be removed.

For this reason be sure if you do use the Yamabond use the Yamabond 4 and not the 5 as the 5 will harden, the 4 is more RTV like.

For what it is worth, the early VW cases had 12mm studs. the "AS41" case (more magnesium for additional hardness) started part way into the 1971 production year still had 12mm studs. Denoted by AS41 0n the lower case half, this case still had 12mm studs without inserts and still screwed directly into the case. In ~1974-75 VW started
Installing steel inserts in the cases for 10mm studs. Some of the inserts were open to the inside. In any of the case combinations I've never seen a stud leak oil at the threads when properly installed. An exception
to this is in early "soft cases", prior to the introduction of the AS41 case, head studs would pull the threads out resulting in an oil leak, and a loose cylinder head.
As a last note, VW did require the use of their case sealer on the studs that penetrated the case to the inside, through a case insert or not.
FWIW
My 2 cents worth
Sticking my nose in, etc.
Frank
ONEX 090
N1970T