rebuilding · FF-0490

What should go on head bolt threads when they are torqued?

It depends on the engine. On an old six-cylinder Steve's best guess is engine oil, and he suggests forums for that engine. Some modern engines go together dry, and ARP sells its own graphite-based lubricant. The lubricant matters because torque only gives the right bolt stretch if the threads turn freely; if they were locked by rust, 50 foot-pounds would not tighten the bolt at all.

Expert

Steve Coppock

Evidence

expert attributed

Component

head bolts

Applicable scope

General engine practice; not specific to the Flathead; asked about a 1977 250 inline six