912ULS Headbolt replacement

I am wondering if you put red Locktite on the case end and then torque it in to the relatively mild 90 in-lbs, then if it sets long enough for the Loctite to fully cure, when you torque the head nut to its hi recommended value the case end may not turn to tighten up to the same torque value. So that end is just held in by the Locktite and a small torque. Years later the Loctite may deteriorate from heat, etc. and fail; now that whole stud has no proper torque and could easily back out.

The solution is easy; don't put the case end in with the Loctite until you are ready to also torque down the heads without too much delay.

When you Apply Torque to a Bolt/Stud the object is Not to twist(Torque) it.

The object is to apply compression to the connection via the tension in the hardware.

Torque is just a crude but convent way to gauge the tension.

The tension(Torque) is the same throuout the length of the stud; With or without threadlocker.

The Locktite is only there so that on the day when the head nuts are eventually loosened, the threads on the case end of the stud don't turn instead.

Under any crankcase conditions normally seen in a 912 engine, the Lockitite is never going to exibit any noticabe deterioration due to heat and age.

The Locktite spec sheet shows 100% of initial strength still remaing after being immersed in 125°C (257°F) Motor Oil for 5000 hours.

That would place the engine in its second TBO Rebuild and still going strong.

The reason that Victor's Stud turned out is that the assembler at the fatory was having a bad day and forgot to locktite the stud in.

The missing Thread Locker was a non-issue and would have remained a non-issue forever had the head never been removed.