What is the sequence for tightening head bolts?

These head bolts need to be tightened in a very different fashion. Normally you would tighten conventional head bolts in a crisscross pattern in three steps, to one-third, two-thirds, and then to the final torque. Stretch bolts are tightened in a torque-plus-angle sequence.

What is a torque sequence?

Bolt tightening sequence, or torque sequence, is defined in the torque tightening procedure. Flange joints are torqued tight with the help of a torque wrench (manual or hydraulic). Torque bolts and nuts in a “CRISS-CROSS” sequence using a minimum of three torquing passes and the maximum bolt stress as defined.

What procedures should be followed for installing and torqueing the cylinder head?

General Manager at…

• Before installing the cylinder head, rotate the crankshaft to the top dead center position of the first cylinder.
• When installing the cylinder head gasket, the side marked (part number) must be visible.
• Replace the cylinder head fastening bolts.
• Tighten the cylinder head bolts with a torque of 40N.

How do you torque a bolt?

Place the socket and torque wrench on the fastener and tighten the bolt, holding the torque wrench by the handle at the end of the wrench. Rotate the torque wrench slowly and smoothly, continuing through the arc until the wrench clicks. The click indicates that you have reached the desired torque.

Why do you torque head bolts?

Some head bolts can be reused while others can’t. Many modern engines use Torque-To-Yield (TTY) bolts, which can’t be reused. These bolts achieve clamping force by stretching during the torque process. Other bolts, such as the high-strength bolts and studs from ARP can be reused over and over.

How do you sequence torque?

Tightening sequence The first pass, lightly tighten the first bolt then move directly across or 180 degrees for the second bolt, then move1/4 turn around the circle or 90 degrees for the third bolt and directly across for the fourth. Continue this sequence until all bolts are tightened.

Do you have to torque head studs?

Do I need to re-torque my head bolts or studs? If you follow the ARP installation instructions, there should be no need to do a re-torque. However, it may be necessary under certain circumstances if the gasket manufacturer’s instructions require it, particularly if a fire ring has been installed.