Another loose head stud nuts thread

[rs911t]

Gang,

This morning I check all my head stud nuts. I found two quite loose. Grady suggested I cycle thru all and retorque, first at 50%, then 75% and finally 100% spec (or 16, 24 and 31 nM, respectively) and record which moved. The results are in the following table:



The good news is each took full torque without signs of the studs moving or pulling at the base. The case is a 2.4 (not 7R), steel studs (they're magnetic) and no obvious helicoils or case savers.

Thoughts?

BTW: the directions (NW, SW, etc) are relative to facing the top of the head.

[john walker's workshop]

the head nuts really should stay tight if all the engine mating surfaces are on the same plane. case halves centerline, cylinder bases where the cylinders sit on the case, head to cylinder contact area. the heads and cylinder bases on the case are the main culprits.