The camshaft is mounted on top of the cylinder head; in five journals; retained by five bearing caps.

These five camshaft bearing/journals are located at the headbolt areas of the head. The camshaft is a hefty piece of rather brittle and stiff iron.

When a cylinder head is made, machined, and heat treated, the camshaft journals are align bored and honed.

When a cylinder head becomes warped due to overheating, the camshaft bearing journals also warp out of alignment. After removing the camshaft, I checked the cam journals for alignment: they were off about 0.032in. Number 3 journal [the middle one] was the high point. A straight edge laid in "flat" from number 1 to number 3 had a 0.032in gap at number 5 journal. The gap was the same at number 1 journal if the straight edge was laid "flat" from number 5 to number 3.

The desired alignment is in the range of less than 0.001in variation; preferably less than 0.0005in.

When this head was resurfaced, the camshaft was NOT removed and the journals were not checked. The journal warpage of 0.020in was NOT detected and corrected. The warped head was resurfaced while the camshaft was still in place stressing the head casting through it's bearing caps.

This was done as a quickie repair: fast and cheap.

The head was reinstalled. The headbolts were torqued down. In this instance, the headbolts were not just clamping a headgasket. They were also fighting the stress of a misaligned camshaft....in other words, the headbolts were trying to bend the camshaft as well as clamp the headgasket. That is beyond their design parameters.

The bottom line:

There is no way that the headbolts could possibly bend the camshaft AND clamp the headgasket sufficiently to contain the combustion pressures and seal the water passages between the head and block. 10,000 miles later, the headgasket failed and the engine overheated....again.