Santana 27 exhaust system

[sastanley]

Laszlo, There you have it...from the legend himself!

[Laszlo]

Hi Don,
Thank you for your advice on this, I greatly appreciate it. I already repaired the water jacket crack with JB weld and the repair kit last fall. I had prepared the surface (sanding), and a bought a brand new side-plate from you guys. I also applied the sealant on the gasket, so I believe the water jacket side cover is sealing well now. I will proceed with the steps you suggested for JB welding the block top surface to remove the impurities. I will also probably get a few new studs, because the old ones definitely have some erosion on the bottom of the threads. I will try to JB weld those crack as best I can, and JB weld the studs in place for those two holes.
However, I fear that if I JB weld all the studs in place, I will never be able to remove the head again. The last time I re-installed the head, it didn't fit right on, I had to gently tap on either side to make it slide down along the studs. There was a ton of friction there. Perhaps I will try to JB weld only the studs with the cracked holes, and the rest of the studs I seal with thread-locker.
~Laszlo

[sastanley]

Laszlo, you can use the head itself as a guide for re-fitting those loose studs into the block. Do not try to get it on all the down, just use it as a guide to allow the adjustment of the pesky stud(s) to reduce the friction you were talking about during the last installation.

Generally, if you have 4 threads on the water jacket side of the stud, it is considered OK, but personally, I would replace any that are suspect. I pulled the manifold for repair of one bad stud, but while I was already in it that far I got three new studs, and larger shouldered nuts at Ken's suggestion and considered it money well spent. Also keep in mind, that if in fact you are not able to repair this block even with Don's help & guidance, all these parts you are buying will move over to another engine block!!

[Laszlo]

Hi Stanley
Thanks for the input, but I am not sure what you are suggesting. Do you suggest that I install the studs with slow-cure JB weld, but not tighten them up completely? Then use the head, do a fit check, and then try adjusting the studs if the head doesn't fit perfectly? Then iterate, until, it slides on nicely?
~Laszlo

[sastanley]

Since I am not doing the work I don't have to think about all those things...but the slow cure JB Weld I think should provide sufficient time to align everything with a couple adjustments, and then if the head slides up and down nicely, you can remove it and let the epoxy cure.

If you have not been using anything so far and a stud(s) out of alignment, that would suggest that even with dry studs there is a problem with threads/alignment, I think.

I would get everything to fit dry first, and then mix up some JB Weld and re-align with the head as a guide, allow to cure, and then I won't have to force the head on.

We are getting into theory now though on my part...I haven't actually tried this particular procedure.

[Don Moyer]

Laszlo, ditto all of sastanley's input. With specific respect to my earlier posting, you need have no fear of removing studs later after using JB Weld. A little heat (very little) will enable you to remove the studs later if you wish. Don

[Laszlo]

Thanks again! I will give it a go.
~Laszlo