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What is the head bolt torque?

What is the head bolt torque?

A crucial component of engine building is setting the torque on head bolts. Torque refers to how tight a bolt should be. When setting the torque, reliance on the specifications set by design engineers is vital. One essential tool you must have is a good quality torque wrench.

What is the sequence for tightening head bolts?

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. Various engines use similar but different sequences and specification.

How tight should head gasket bolts be?

Many cylinder heads require multiple torque sequences to achieve proper tension. For example, a 10-bolt cylinder head may require you to tighten them all first to 42 foot-pounds in a specified order, then to 75 foot-pounds in the same order. Improper sequencing or torquing of the bolts may result in damage.

What is the final step after torquing head bolts?

The final step is to twist each bolt a specified number of degrees to stretch the bolts to their design limit. * If a bolt breaks when you are tightening it, you may have over-stretched it. Or, there may be debris in the bolt hole that is binding the bolt.

What happens if a bolt is under torqued?

Typically, an under torqued bolt will deform and be unable to provide as much clamping force as needed. An over torqued bolt will break.

What are the torque specs for a Ford engine?

Ford Engine Bolt Torque Chart Fastener Type Torque Spec Main cap bolts 60-70 ft-lbs Outer 2 bolts of main cap bolts 35-40 ft-lbs. (for 4 bolt main bearing c Connecting rod bolts (40-45 ft-lbs. for 289 HP & Boss 302) Cylinder head bolts 65-72 ft-lbs.

What are the torque specs for stock bolts?

These specs are for stock-type bolts with light engine oil applied to the threads and the underside of the bolt head. Moly and other lubes offer reduced friction and increased bolt tension, which will affect the torque figure. If you use after-market performance bolts like ARP’s, you should follow the recommended torque specifications.

How big are the bolts on a Ford Mustang?

Ford Engine Bolt Torque Chart Fastener Type Torque Spec Main cap bolts 95-105 ft-lbs Connecting rod bolts 40-45 ft-lbs. Cylinder head bolts 90-100 ft-lbs. Rocker arms 17-23 ft-lbs.

What are the torque specs for a boss 351C?

If you use after-market performance bolts like ARP’s, you should follow the recommended torque specifications. 351W Torque Spec. 351C, 351M Torque Spec. 40-45 ft-lbs. (45-50 ft-lbs. For Boss 351C) 105 ft-lbs. (125 ft-lbs. For Boss 351C)