thermostat housing bolt hole questions

[Anonymous]

Boy, have I been having fun . Went to do a simple thermostat change. First bolt, on the right facing engine, loosened easily. As soon as I started trying to turn the bolt on the left I knew I was in trouble. Some moron had put a grade 0 (only a slight exaggeration) bolt in. Head turned off in spite of my careful efforts. Try heating around the bolt, penetrating oil, GENTLY tapping, etc. The bolt ended up being flush with the head. The good news was it was easy to drill through since it was so soft. The bad news is the bolt was so soft the "easy-out" just turned, left-twist drill bit just drilled without loosening the bolt. Kept drilling bigger and bigger until I was able to pick the remaining bolt pieces out.

Now for my questions. The bolt hole on the left, facing the engine, is all the way through the cyclinder wall into the water jackect. This was the way it was before I started drilling (I check with mirror). Is this the way it is supposed to be?

I put a thread-chaser into both bolt holes to clean them up. Both bolts are a little loose in the holes (new grade 5 boltds). How do I keep the bolt hole on the left from leaking since it is into the water jacket? I do want to be able to remove the bolt in the future.

I do plan on buying of of the new aluminum cylinder heads and one fo the intakes but for now I need a solution.

 

[63redtudor]

Just to be sure, I checked the spare heads that I have & yes, that hole is supposed to go all the way through. There's a sealer you should put on that bolt, I couldn't find any on hand, but most places should have it. I know that there's at least one head bolt that goes through the water jacket as well, use the same sealer as you would for it.
Edwin

 

[LaGrasta]

Wow, I didn't realize that bolt went all the way through to the jacket. I just replaced mine and didn't use any sealant there. I don't think it's leaking by some miracle. I guess teh gasket keeps the water from getting out.
As for the sealant, use Thread Sealant. You can find it near the Thread Lock.

 

[Nutz4mystang67]

Also remember that the bolt on the right(facing the engine) needs to be just long enough so it does not hit the cylinder wall

 

[Anonymous]

Thanks guys. I will pick some up tonight and hopefully be able to put the car back together this weekend.

 

[gtm1086]

Use Permatex #2 on the threads for any bolt that goes into a water passage.