head bolt/studs are blind, the only thing that should be on studs is a light lubricant in order to ensure the correct torque is applied, anything like silicone will cause a erroneous head torque reading, which can cause numerous issues, including leaks and catastrophic failure in some case, of course 75+ engines later, i could be wrong.....
Dodge29
I agree. I researched bolt torquing at work years ago. A coworker had a chart from Rocketdyne and NASA. We strive for the correct linear tension (stretching force) in the bolt, inferred from measurements of the twisting applied (torque). The later is affected by both thread angle and friction in the threads and nut surface.
If you oil the threads, it does not increase the final bolt tension beyond what you would get from clean, dry threads. This is a bit surprising. Apparently, the oil gets squeezed out at the high pressure. Oil does give more repeatable results than with dry threads.
If you use a high-pressure lubricant like MbS2 powder (or moly grease) on the threads, the bolt tension will be ~2x higher, even more if you put MbS2 under the bolt head. If torqued to the normal "lightly oiled" value, the bolt may break. I don't know about silicone that Dodge29 mentions, but avoid it also.
Use minimal oil and probably a light one like SAE 10 ("3-in-1") or WD-40. The danger is filling the hole with oil and realizing "hydraulic lock", where the bolt "bottoms out" on the oil and isn't tight (head gasket leak).
Blow out each hole to insure it isn't filled with oil, water, anything else that could bind the bolt. I first install each bolt with the head off to insure they go in smooth and measure they go in slightly deeper than the thickness of the head. If any threads are rough, run a tap down them. Usually clean because oil sits on the threads.
