rebuilding · FF-0491

Do head bolts need thread locker?

No. Torquing a bolt stretches it, and that stretch lets the bolt move with the head, block and gasket as they shift a little, if it is tightened properly. Steve says there is no need for thread locker, lock nuts or anything else on a head bolt.

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