Head studs leaking coolant

[carl hinkson]

Originally Posted by Tim H

Looking for opinions on the best type of sealant to use on ARP cyl. head studs. Fresh BBC and only minutes after initial fire up some of the lower head studs started to leak. After checking the torque of 80 ft lbs and re-torquing the leakers to 85 ft lbs, we restarted the engine only to discover that many more were now leaking including the ones that had just been torqued.I had used ARP thread sealant and run a tap through all the holes prior to assembly. The studs are new, head gaskets are Fel-Pro 1017-1 on a GM 454 block, using GM "990" cast iron heads. Engine is now back out of car and on the stand.
Never had this problem on my old 468 using same stuff ?

85 FT LBS on head studs on a OEM block that's alot !!!

Hopefully you block was plate honed with studs torqued that much ?? GM blocks are pretty frail compared to an aftermarket block.

If not a leak down test at TDC and 40 degrees Before or after TDC will not be good.

http://www.chevelles.com/forums/13-p...te-honing.html

Head studs are always a pain to seal and should be lock tightened in

ARP sealed works the best, Never seen Aviation sealer work on head bolts once it gets hot it solidifies.

GM seal tabs work great for leaks P/N 10-108