Cylinder Head Bolt Torque Values (2024)

FAQs

Cylinder Head Bolt Torque Values? ›

Tighten Cylinder head bolt to 7.5 kgfm (Hold for 3 seconds) in sequence as marked. for 10 seconds.

Tighten Cylinder head bolt to 7.5 kgfm (Hold for 3 seconds) in sequence as marked. for 10 seconds.

They should be torqued to 60NM, +90, +90 degrees on a cold engine.

Do the head studs only go in hand, or finger tight? Yes, cylinder head studs are installed only hand tight.

For cylinder head bolts to work properly, it is very important to follow the instructions and specifications for tightening and fitting cylinder head bolts exactly. If this is not followed, larger sealing problems such as leakage may occur. Over-tightening of bolts can also lead to damage and incorrect sealing.

Torque-angle Method

In the first step, the bolt is snugged down to the cylinder head by means of a pretorque. With the second step, the so-called torque or tightening angle, the bolt is tightened into the plasticregion, i.e. beyond its elastic range.

Initial tightening: An initial tightening is performed at a specific torque. This tightening ensures that the cylinder head gasket is properly seated and that the engine components are in their proper position.

Oil leaks: you may not be aware of this, but cylinder-head bolts are largely responsible for the sealing between the cylinder head and the engine block. If they are applied incorrectly or without the due pressure, oil leaks might occur, compromising not only the engine's performance, but also its lubrication.

HI,Over torquing the head bolts can mash the head gasket enough to cause leaking or loss of compression, it can also stretch the bolt threads, which leads to loosening of them allowing the headgasket to leak or worse case, the head to warp.

Recommended torque is equal 75% of the fastener's yield strength. Simply read down to the correct fastener size, then across to find the torque value for your application. Always lubricate the fasteners prior to applying torque to ensure accurate readings.

What is the preferred procedure for torquing cylinder head bolts? ›

Usually it is a two-step process; go through the pattern tightening the bolts to maybe 45 ft lbs and then going through the sequence again tightening them to their final torque of maybe 85 ft lbs. There is no one-size-fits-all. Each model of engine has their own torque specifications and tightening sequence.

If the head isn't torqued down properly, then the most likely failure is of the head gasket, which could lead to loss of compression, the mixing of oil and coolant, exhaust gases getting into the oil ways or cooling channels, erosion of the cylinder head, overheating and warping of the cylinder head.

HI,Over torquing the head bolts can mash the head gasket enough to cause leaking or loss of compression, it can also stretch the bolt threads, which leads to loosening of them allowing the headgasket to leak or worse case, the head to warp.

Each vehicle type has different torque specifications, set by the manufacturer, which must be respected when servicing the vehicle. Not only for the wheels, but also for any other bolted parts such as the cylinder head, a torque controlled solution must be used to tighten at the required torque.