Do you tighten the nut or the bolt head?
In this situation, apply tightening force to the smaller bearing face. For instance, if the bolt head is smaller than the nut, you should tighten the bolt head and not the nut. Apply tightening force to the part that’s against the material with a lower coefficient friction capacity. Torque on the side that’s likely to produce the least friction.
How do I know if my head bolts are torque to yield?
If an engine produces 1,500 pounds of pressure and the cylinder head has 8 bolts, then each bolt must be tightened to 187 foot-pounds of torque to secure the cylinder head to the block. Likewise, how do you know if a bolt is torque to yield?
When to apply tightening force to a nut?
Apply tightening force to the part that’s against the material with a lower coefficient friction capacity. Torque on the side that’s likely to produce the least friction. In this scenario, the tightening force must be applied to the nut to avoid torsional wind-up issues.
Can a torque wrench be used to tighten head bolts?
One of the most common misconceptions about using a torque wrench to tighten head bolts is that the torque reading on the wrench indicates how much load is on each bolt. The reading on the wrench only tells you how much twisting force is being applied on each bolt.
How many head bolts do you need per cylinder?
If each cylinder has four head bolts around it, each bolt has to exert a clamping load of 10,375 lbs. If there are five head bolts per cylinder, the load needs to be 8,300 lbs. per bolt. If there are six bolts per hole, then the load required drops to 6,916 lbs. per bolt.
Why is it important to tighten head bolts on gaskets?
This is especially important with gasketed surfaces because the gaskets have a certain amount of give that must be overcome by the fasteners to maintain a tight seal. When you tighten a head bolt, the force exerted by the wrench is accomplishing two things.
Why are head bolts supposed to be in perfect condition?
Consequently, it’s extremely important that all the head bolts be in perfect condition and are installed and lubricated properly so they are not overloaded. Though head bolts seem to be pretty rigid fasteners, they are actually designed to stretch. Stretching a bolt is like stretching a rubber band.