Importance of Proper Torque
When a head gasket is installed between the cylinder head
and engine block, tightening the head bolts compresses the
gasket slightly, allowing the soft facing material on the
gasket to conform to the small irregularities on the head and
block deck surfaces. This allows the gasket to “cold seal” so it
won’t leak coolant before the engine is started. The head
gasket’s ability to achieve a positive cold seal, as well as to
maintain a long-lasting, leak-free seal depends on two
things: its own ability to retain torque over time (which
depends on the design of the gasket and the materials
used in its construction) and the clamping force applied
by the head bolts.
PermaTorque® head gaskets are made with top-quality
materials and designed to remain resilient so they retain
torque, so no retorquing is necessary. (Some competitive
head gaskets alleged to be “no retorque” can lose as much
as 50 to 60% of their original torque after only 100 hours
of service.)
Competitive Head Gasket:
PermaTorque® Head Gasket:
III
