Why should head gasket bolts be tightened in a criss cross sequence?
A good tightening sequence ensures that an even preload distribution is achieved in the joint (See Dia. A). Since joints containing conventional gaskets have a comparatively low compressive stiffness, bolt preloads in such joints are particularly sensitive to the tightening sequence.
What happens when you tighten the bolts on a gasket?
With the ends of the head now locked in place by the end bolts, you now tighten the ones in the middle forcing the arch down. This will cause movement on the end bolts. There is a good chance now that the gasket will fail to do its job.
Which is the correct way to tighten a cylinder head?
For example, a typical cylinder head tightening sequence might look like this-. Tighten all bolts in sequence, and in two stages to a snug torque value of say, 30 Nm. Apply a 90 degree rotation to all bolts in the proper tightening sequence. Apply a further 90 degree rotation to all bolts in the proper tightening sequence.
What should I do before installing a gasket on my head?
Before installing, inspect all of the bolt threads. And replace deformed and worn threads. Even if all of your head bolts are brand spanking new, it won’t matter if the bolt holes are deformed or dirty. In most cases, you need to run a bottoming tap down each of the holes.
How to tighten engine bolts the right way?
1 Tighten all bolts in sequence, and in two stages to a snug torque value of say, 30 Nm 2 Apply a 90 degree rotation to all bolts in the proper tightening sequence 3 Apply a further 90 degree rotation to all bolts in the proper tightening sequence
With the ends of the head now locked in place by the end bolts, you now tighten the ones in the middle forcing the arch down. This will cause movement on the end bolts. There is a good chance now that the gasket will fail to do its job.
For example, a typical cylinder head tightening sequence might look like this-. Tighten all bolts in sequence, and in two stages to a snug torque value of say, 30 Nm. Apply a 90 degree rotation to all bolts in the proper tightening sequence. Apply a further 90 degree rotation to all bolts in the proper tightening sequence.
How to tighten engine bolts to yield torque?
How to tighten torque to yield bolts 1 Tighten all bolts in sequence, and in two stages to a snug torque value of say, 30 Nm 2 Apply a 90 degree rotation to all bolts in the proper tightening sequence 3 Apply a further 90 degree rotation to all bolts in the proper tightening sequence More
Before installing, inspect all of the bolt threads. And replace deformed and worn threads. Even if all of your head bolts are brand spanking new, it won’t matter if the bolt holes are deformed or dirty. In most cases, you need to run a bottoming tap down each of the holes.