Lifter (Rocker?) Noise w/ Rebuilt Heads

Hi Everyone-

I just had the heads rebuilt on my '73 302 and it's running fine except for some noticeable (what I think is) lifter noise. It ran for about 15 minutes total and wasn't going away. The machine shop noted that the heads had been faced before (to almost the limit) and they did what they could and then recommended a cylinder head shim which I followed. Since they're positive stop hydraulic there isn't any adjustment I can do for lash. When the valves are closed I can slightly move the rockers back and forth across the top of the valve, but it's not egregious.

I'm wondering if I need slightly longer pushrods now (either rockers/ pushrods wore down with the reduced height after the first cylinder head facing) to take that movement away, or if I just need to let it run longer and make sure the lifters are re-primed. I did not replace the lifters. I'm not sure how much play is okay. I found something about seeing how many turns the bolt takes after you can't turn the pushrod by hand until the bolt bottoms out and that fell within spec.

Any thoughts? Thanks everyone!

Got it- makes sense. I need to try and isolate which lifter. The ticking was fairly faint as I could only hear it if I was under the exhaust manifold.

I'm also wondering if I didn't let it go long enough to let the oil warm up and get to work- I run a straight 30 (always have, it's what is listed on the valve cover), and the block was around 30 degrees this morning.

Probably some good info to know would be,

Did it have the noises before the machine work?

How much did they cut down the heads?

What was your shim thickness? Most are .020 inches

What was the thickness of the new head gaskets?

Are all or most of the lifters making the noise?

Check the link below for some discussion of preload and there's a link in the linked thread to a Ford tech sheet on how to check preload

It sounds like you may not have enough preload and need longer pushrods, like you're thinking

After 15 minutes of running, your lifters are primed (or broken if they're not)

link

Mark - pretty sure the 460 has the later style pedestal rockers which are much different than the old style positive stop ones that he's is using

Pedestal mount rocker-


Positive stop rocker

Replying to KENO's questions:

- No noises before machine work
- It sounds like they weren't able take much off because they felt like it was already near the limit
- Shim was .02
- Head gasket thickness is .049
- It sounds like just a few are making noise

This thread looks very useful. Thank you!

Gary, you are correct the 460 had the pedestal with the fulcrum just like your uppper picture.
My 78 351W had what you call positive stop in the lower picture. Mine were converted to adjustable rocker arms which look just like your positive stop but have more threads on the rocker arm studs.
Sam, if you find your noisy lifter add the shim as mentioned, the shim will add a little pre load and your lifer should be quiet as soon as you start the engine.

You can run the engine valve cover off and verify you have it fixed before buttoning it up.
They make tools to keep the oil splash controlled while doing this but I have had good success using cardboard for a one time use. Cut some cardboard about 10" tall and 3' long.
Bend it to fit inside the top of the head, make a rectangle that fits tight giving you full access to the rocker arm nuts from above and oil spill protection below. The 10' of cardboard catches oil splash and feeds it back where it belongs. Protect your carpet as you will get a small amount of spill.
If you get a big leak oil can burn on the exhaust so be smart and use a good splash gaurd.

If you add a shim and the noise is gone right away but comes back after 5 minutes you are in trouble. A cam lobe is going flat.
If you add the shim and that exact lifter refuses to quiet down at all you have a lifter failure, the internal adjustment in the lifter is probably stuck and you might need to replace it.
About 1 in 20 will clear up and start working if you blast high pressure air down the push rod while keeping a lot of pressure on the lifter. Sometimes they stick due to a small particle of some kind inside the lifter body and the air once in a while can free it up. Not likely but like I said, 1 in 20 it works. For the amount of time it takes to test with air, 5 minutes maybe, it might save you removing the intake to replace the lifter.
Lets hope the shim works!   
Or as mentioned, you might have an exhaust leak you are chasing, they sound similar.

Lots of variables at play. Sounds like you didn’t take it back to the basics and measure what your installed lifter preload actually is? I would do this on all rockers. It’s highly likely that shim thickness will vary valve to valve on rebuilt heads. Shimming is SOP on non-adjustable ford Windsor heads when they’re reworked.