‘87 5.7 top end rebuild develops knock n shake

[Dont fake it break it]

Are you sure it's not the TBI injectors ticking? My ears suck, with a stethoscope (super cheap on ebay) I can hear but not pinpoint a ticking in mine. I figure it's the injectors or aftermarket roller rockers for some reason. Its run with that noise a long time, so I'm leaving it alone lol.

You’re absolutely right that my injectors tick like crazy. It’s very distracting and deceiving. I did another valve adjustment last night and had some success in noise reduction but the rocker arm nuts keep working their way loose. I think I’m doing it right but can’t explain why new nuts would do that. It also doesn’t seem like there’s enough torque on them when they’re finally adjusted so wondering about that too. In fact they don’t seem like there is the same torque applied on all of them and I would think it would more or less be the same. Some have no resistance after getting to 0 lash plus a three-quarter turn, and some seem like they got 5 pounds of resistance. Checking them again right now there’s at least one that’s barely finger tight. Even valves fully closed wouldn’t there be some pressure on it?

 

[dyeager535]

I've never had any issues doing rockers. I'm using full rollers now, so it's not a lock nut that has inherent tension.

There are a lot of variables. It's possible the tick you are hearing is a bad lifter. If one or more arent pumping up, or lose pressure quickly, I suppose the nuts could appear loose.

Those nuts are supposed to be one time use, if on their first use, they certainly shouldnt be backing off.

 

[Dont fake it break it]

Hmm. I definitely ordered rocker arm nuts but they look like they are just standard grade 8 nuts I got from the local O’Reillys. The lifters are all new. However I never knew anything about pumping them up with oil or how to do the valve adjustment if they are full of oil or not full of oil. I installed them, primed the oil pump till I had at least a trickle before I ever assembled the engine and did the first adjustment so I thought I was good. However I Did see air bubbles coming out of the pushrods for a while but I think it’s stopped now.

 

[dyeager535]

If they are working correctly, even if they "lose prime" they pump up essentially instantly.

When a lifter "collapses", you will hear it as a tick that most likely never goes away, and is obviously dependent on engine RPM.

 

[Dont fake it break it]

If they are working correctly, even if they "lose prime" they pump up essentially instantly.

When a lifter "collapses", you will hear it as a tick that most likely never goes away, and is obviously dependent on engine RPM.

That’s good information. I never knew that they would lose prime and with the engine shut off that there would actually be slack again until they pump up. That alone has probably caused me to readjust them several more times. I’ve been trying to do it as soon as I turn it on before I gets too hot. Perhaps I should give it a minute or two to make sure they are pumped up? My oil pressure is also on the low side so maybe that would cause it to take a bit longer?

 

[bp71k5]

I’d say you also can’t use regular nuts from oreillys. The correct ones are friction fit and if you aren’t using them, they will loosen up quick.

 

[dyeager535]

They dont all lose prime immediately upon shutdown, my understanding is its just that old ones CAN leak a bit, causing them to lose prime somewhat quick.

I never liked the normal valve setting procedure because of the variables. And if you have leaky or failed lifters, that messes the process up more, as there is no consistency valve to valve when setting.

As mentioned, those nuts need to be lock nuts, stover nuts were what was used by GM. That alone could be the problem if they are non-lock nuts.

 

[imiceman44]

That’s good information. I never knew that they would lose prime and with the engine shut off that there would actually be slack again until they pump up. That alone has probably caused me to readjust them several more times. I’ve been trying to do it as soon as I turn it on before I gets too hot. Perhaps I should give it a minute or two to make sure they are pumped up? My oil pressure is also on the low side so maybe that would cause it to take a bit longer?

Another thing to check, I don't know what kind of rocker studs you have but I had an engine that had that problem, it had stock press in studs and they were pulling out and messing the adjustment

 

[Dont fake it break it]

Another thing to check, I don't know what kind of rocker studs you have but I had an engine that had that problem, it had stock press in studs and they were pulling out and messing the adjustment

Hell I never thought of that. I did actually watch 1 but back itself off though. When I got the heads back from the machine shop, I never thought twice about em. I’m kinda trusting.