As the subject says it, my #1 cylinder exhaust valve's roller rocker adjustment has been a nightmare. I've adjusted all the valves to 3/4 turn past zero lash, and I am using brand new Crane OE lifters and a CC 305 cam. On the Comp Cams rocker arms, I adjust the nut to zero lash, go 3/4 turn, then screw down the set screw tightly with a 3/16" alan key. I go WOT to about 6000-6200 rpm for a couple gears, then when I'm idling, I can tell by the tap that my rocker arm has come loose again. The set screw backs ALL the way out (to the very top of the nut). I am thinking I may have to replace the whole nut and set screw, because the threads on the rocker stud look fine. Any suggestions?

Thanks in advance,
JR

 

Maybe try some high temp threadlocker on the set screw.

 

If the top of the stud is not flat, it may not hold. Is that stud different from any others? Just to rule out the nut, swap it with another and see if the trouble stays in the same place.

 

Good idea shoebox, I'll try that next time... in the process I'll check the tips of the rocker studs. I'd rather not use Loctite because if something's wrong there, I don't want to mess up anything else in the process. In the meantime I'll cross my fingers and hope it doesn't break at the wrong time.

Peace,
JR

 

I'd use some type of threadlocking compound!

 

The last guy that used threadlocker posted on here that he could not get them unlocked. I don't recommend that. The torsion lock of the set screw should work. Since you only have one that is not staying locked, obviously there is a problem with it, only.

 

Woh..It sucks.

 

You might try what I do, and that is once I get the set screw tight I JAM it and the main rocker bolt another 1/8'th of turn or so by reefing on both simultaneously. Those suckers are brutally tight then.