I ask after a long debate with a good friend and fellow gear head. he says he doesnt apply any sealent to the threads on head bolts, just a little bit at the top of the bolt below the head where it meets the surface. I always put a little bit of silicone on the threads to keep coolent out. He says putting it at the top of the bolt does the same thing. He doesn't like anything but oil on threads because he thinks it alters torque readings. I do it my way he does it his and we both swear our way works. just curious what engine builders on the hamb think?
I do it on SBC engines where there is interface with the water jacket as security. DON'T do it on a Chevy inline 235 six! Oil flows up around one of the center bolts to the rocker shaft. Sealant will clog the oil p***age at the head gasket. Don't ask me how I learned this little tiny bit of trivia....
yes, we were talking about small block chevys. I had always been taught that you need to seal the threads in the water jackets. He says he hasn't had any leak doing it his way. Got me thinking, looking for more opinions!
ARP Thread Sealer, on the threads and under the head of head bolts that go through into the water jacket.
GM thread sealer, strangely enough. goopy honey-like stuff. smells really nice!! I use it on flathead head studs, never had a weepy stud using this stuff.
I always use the ARP products with my ARP bolts and you must follow ARP's torque specifications as well ! Retro Jim
The brown Permatex goo in the white bottle with the brush attacked to the cap.This stuff works better than anything on less than clean threads.
As an aside.... Don't use sealer on the end of a bolt if the tapped hole has a "bottom" to it, especially if you are reusing head bolts. The bolts will have stretched and putting anything that would effectively make the bolt "longer" will cause disasterous effects when you torque that baby down into a "too shallow" hole. Like the man above said: "Don't ask me how I found this out"....
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