ford 302/289 valve adjustment question

[UKjohnnycobra]

I have a 1968 vintage 302 with 1966 vintage heads from a 289. I think the valves are out of adjustment. I have followed the "accepted" procedure of; seating the valve; loosening the rocker nut; waiting a couple of minutes; and then tightening the rocker nut unitil I can no longer turn the pushrod by hand (zero lash); and then giving it another half turn. The thing is after a couple I've done this, the pushrod loosens up again (possibly due to the relaxing of the lifter?). Should I retighten the nut a second or even third time, or is zero lash established the first time I tighten it?

All help is gratefully received and thanks.

[Jac Mac]

Zero lash should be what you got on the first attempt. As you rotate the engine to set others the valve springs will collapse the lifter and give you the impression that its wrong-dont worry its normal. When you first start the engine after setting these there will be some tappet noise until the lifters pump up to there normal run position.

Jac Mac

[troll]

check to see if the studs are pulling out.Most fords dont use screw in studs

[UKjohnnycobra]

Guys thanks for the input. Jac Mac I followed your advice and got a real improvement. Clearly the valves were overtightened and I thinbk I was losing compression. Car now starts better and runs smoother. I think I can now back off the timing a bit which I will try next week. Thanks again