Wendell Allen

Been driving my '77 as a daily driver for a month now with no valve train problems - till now.

Yesterday I noticed a slight clicking sound coming from somewhere in the top end of the motor, so today I decided to adjust all the lifters just for grins. left bank was fine. However, #6 on the other side was a problem right off the bat. I noticed that the bolt on the intake side was backed way off, to the point I was able to remove it without a ratchet/socket. So I pulled the rocker arm and push rod off to examine them. All looks fine to me. I thought maybe the nut just backed itself off, so I tightened it back up just to confirm my thoughts. I noted that all the other rocker arm studs were protruding about 1/4" past the top of the nut, so I tightened #6 down that far as a baseline.

Then I fired up the engine to adjust it. The engine had a noticable miss then, so I started backing off the nut to find my adjustment point. And to my surprise, I have to back the nut off so far before I get the clicking noise that it's almost completely off the stud.

Is this what is referred to as lifter pump up? Someone in one of the archived threads mentioned about a missing retainer clip. Could this be happening and it's causing the lifter to try to come apart, and as a result pushing the push rod too far up?

As always, many thanks.

W

rcastor426

the only thing that i can think of to check without pulling the intake is look at the push rod position when valve is closed then compare it to another closed vavle, if it is sitting higher than the other valve then it sounds like what you have alreayd talked about might be the problem. good luck

BB68Vett

Is it possible your rocker arm stud is pulling out of the head?

Wendell Allen

Why do people do this kind of crappy work?

I noticed when I changed the oil pan gasket earier this week that there was what appeared to be part of a push rod end in the bottom of the oil pan, so I was really concerned that I'd lost one somehow. So I pulled the intake so I could examine all of them. They all checked out fine.

And I'm standing there staring at it and scratching my head when I noticed that the stud for this particular rocker arm is about a quarter of an inch shorter than all the others. Someone put the wrong length stud in it! So my guess is that the nut just eventually opened up enough back itself off. I got a new one and mashed it a little more with a couple of hammer blows for insurance. And I also put a new lifter on this particular cam lobe. The nut's on quite tight now, and I'll just check it periodically until I pull the heads for replacements.

My guess is that this has happened before, hence the push rod piece in the bottom of the oil pan.

And more good news out of this is that I now have a shiny new silver Performer RPM on the car just in time for dyno day tomorrow!

Cheers!
W

Fevre

Good time to ditch those stock nuts and get some polylocks.

burners

Interesting, it sounds like someone just installed it too far. You could just get polylocks rather than the stock style nuts. I would be concerned that there wouldn't be enough threads to hold that rocker on there. It may strip the threads after a while.