Edelbrock Heads - Loose Rockers, Oiling Question?

New motor, another new issue. Do rocker arms back off on Edelbrock heads? I have adjusted them twice now and went for a test drive. As it warmed up, one really started making racket. It got so loud I thought a rod had let go!

Got it home and decided it was a rocker arm. Took the valve cover off and I had one that was so loose it was as if I'd never snugged it down at all. I tightened it back down while it was hot and it sounded good again.

Then, when I revved it up a bit, only the rear rocker squirted oil in a strong stream out of the push rod hole. It was only about 1,000 RPM. Should they more than just trickle at 1,000 RPM with the factory gauge showing half way (30-40psi)?

I've just about got all the leaks and other stuff nailed down and debugged. Just need to resolve this issue.

 

This exact same thing happened to me a little over a month ago. Found 2 loose rockers, one so much so, like you, I thought something big inside broke by the sound it made. Brand new engine, dyno time plus maybe 60 miles. Pulled the intake, here's what I found....

This:


And the one on the right:

 

Ah, crap! I hope that's not what happened to mine. I wonder if I can get an inspection camera in there to check?

Mine only took 1/2 of a turn to tighten back up. Yours look like it would have taken several turns to do anything! I think mine is just loosening up.

Did it turn out OK or is your motor still apart?

 

No, I got it fixed. Long story short, that happened the night before bpg, so I drove an hour to the closest place that had 16 new lifters in stock, swapped them that night, broke in the cam the next morning, did a 1 mile test drive, and loaded it for bpg. Got about 300 miles on it since, so far no issues (knock on wood).

If 1/2 turn took it out, its not the same problem. How much did you preload your lifters originally?

 

We had them loosen initially, and now use a good quality locking nut and give them a little turn after tightening the set screw. No problems since that.

 

I set them at 3/4 turn after 0 lash using the four 1/2 crank rotations to adjust the valves in that fashion.

I did start it with the valve cover off this time to at least be sure there weren't any other noisy ones while I was tightening the obviously loose one.

I just have these locking nuts, not set screws. I couldn't get the set screw stuff to work on this motor. The stud was almost flush with the top of the lock bolt and the set screw was only getting 1/2 thread. No way I was going to run that.

Man, those Chevy guys are masochists to run this nasty stuff. LOL

Nut on stud


Set screw and lack of engagement

 

You could double nut them maybe. I used to do that on my old Chevys.

 

Is the actual nut backing off or is something wearing or out of whack such as the lifters in the picture? Or are the pushrods wearing from lack of oil?
Even with TA roller rocker adjusters or adjustable pushrods I always make sure the thread count is fairly consistent with all the other rockers/pushrods. If they are consistent but something is still noisy then something is worn or wearing. If you didn't have screw in studs I'd say check to see if the studs aren't pulling just like a standard Chevy press-in style.

 

The thread count looks pretty consistent. I'll run it a bit and see. It is a brand new cam, lifters, Edelbrock heads, Edelbrock intake, rockers and pushrods. Nothing used in the entire top end. Only used things brought forward were carb, distributor, coil (now swapped) and temp sensor in the manifold.

 

Cam going away?

 

I hope not! So far it has break-in time and about 25 miles on it! Probably only 2 hours total run time.

It runs like a raped ape when it is right. Unfortunately, it is clacking like a team of steel shod horses on pavement by the time I got it home from a mere 5 mile round trip to town.

I'm too disgusted to take the valve cover off again until it cools. I know which one to look at, 5 exhaust. This time I'm going to check that the stud is still torqued into the head and get a new nut or two. Seems to only be this one.

Is there anything special about these nuts or any better nuts to get than the ones I have in previous pictures? I'm running stock chrome valve covers. Don't think I can run set screw locking nuts without some pretty tall valve covers or a different type of locking nuts.

This is just one of the problems I'm fighting right now.

 

Man, I hope not! I ran it the required 20 minutes at 2000-22000 with cam lube and break-in oil with a total of 25 miles on the clock since break-in.

Anyone got a good way to run with the valve covers off without making the biggest, stinkiest, oily mess in the world?

 

Sometimes you have to peen the top edge of the nut a little more than what they already are. You shouldn't be able to run them down by hand. Even using a ratchet you should feel a fair amount of drag.

 

Get yourself one of those flimsy plastic kitchen counter cutting boards like this one

http://www.google.com/aclk?sa=l&ai=...e3cYCFQGXiAodHcMLUA&ei=LF-mVf75G4GuogSdhq-ABQ
cut it in half, and slip one half between rockers and the lip of the head on the lower side and that keeps the oil from flying out over the head....it should stay in place by itself kind of wedged in there.....

 

Greg,

2 thoughts..

First, whoever said to peen the nut a little on the top is right.. it should have some serious resistance going on.. especially if it's just one nut loosening up.

To cause noise from a cam going away, it would either have to be really eating up the lifter, or wearing out the base circle, I doubt you would see that much destruction in that short time, so I think you either have a stud loose,or the nut is loosening up.


Second, rocker arm clips to keep you from getting an oil bath when adjusting a sbc have been around forever, and since we use SBC rockers on those heads, we can use them..

http://www.amazon.com/AMPRO-T70065-...sbs_263_2?ie=UTF8&refRID=1XD4Q1C0VCWP195NWY7D


With those arms and steel valve covers, how is the noise factor, when everything is tight.. I have not had an opportunity to hear those rockers under steel covers yet.

JW

 

I'm seeing that it's difficult to get GOOD self-locking nuts. The self-locking wears out almost instantly, leaving a nut that turns at will. I wonder if GM still sells "real" Chevy rocker nuts.

An alternative is to get proper-length rocker studs, and use the tall "poly-lock" rocker nuts having the set-screw locking feature. This is my strong preference anyway, because adjusting lifter preload is SO simple when the nuts have almost no friction until they're deliberately locked.

Using a paint-pen available at most hardware stores, I paint a stripe in a high-visibility color on the upper part of each pushrod, high enough to see, low enough to not be rubbed by the pushrod guideplate. Then I cut a viewing slot into a spare valve cover or two. I can run the engine with minimal oil loss while I see the stripes on each of the pushrods spin round 'n' round. They may not all spin at the same speed, but they all must spin.

This is a pair of Pontiac valve covers, but you could do the same with covers to fit Buick:

 

There's an idea! I was looking for something easy and that should do it. Was trying to wedge cardboard in and it was too stiff and absorbs the oil.

That's a pretty good idea. Not dealing with much Chevy stuff, I knew they couldn't possibly put up with this crap for long.

As for noise, when they are snugged up and the covers are on, you can hear a little more noise, a light ticking I suspect is the guide plate/pushrod contact. Over all, with my M/T headers, it isn't too objectionable with the hood down.

I hate to cut up a set of valve covers. I'm going to try JW's and moleary's suggestions. That should get the oil mess under control. Your idea would be great if I had a dented up pair laying around.

I'll be passing by Summit this weekend and I'll check their poly lock selection against my current one to see what options I have. Just want to try and keep my chrome valve covers if I can. Might have to stack gaskets and stud the valve covers.

Cross your fingers.

 

same things happened to my 350, lifter tops flipped. And it cracked something as it slowly got worse n worse about pushing coolant out the tail pipe from #8 exhaust, at first not in the oil, then slowly into the oil. Hence my 430 purchase