454 valve adjustment

[fnny6770]

I have this 1978 454 it does not have a lot of miles on this engine since it's been rebuilt but I hear light ticking and clacking coming from the right side, I haven't ran it yet since I pulled the valve covers off but I'm going to do that soon, are these rocker arms adjustable or are they the torque to spec type? There is one or two that feels a little loose compared to the others, what's the best way to go about diagnosing this?

 

[bucket]

You can't really just guess with valve lash adjustment. But, if you can wiggle a rocker arm up and down, that's too loose.

You can start with a basic valve adjustment.

Are you sure the ticking was not a cracked exhaust manifold, or other exhaust leak?

 

[fnny6770]

At this point I'm not real sure what the ticking sound is, I've heard enough valves over the years that it sounds just like a rocker arm, but then as the engine starts warming up there's also the sound of a light metallic scraping noise that comes louder and louder. And not terribly loud just a little noticeable for someone who's listening. Maybe the scraping noises nothing I don't know yet.

 

[csft66]

Those are adjustable.
Rotate the motor by hand, when the intake starts to close adjust the exhaust, when the exhaust starts to open adjust the intake.
1/2 turn after the play is removed from the pushrod/rocker arm.
Hydraulic lifter cam.

 

[77Dmax]

Solid or hydraulic cam?

 

[xm20k]

I just made a YouTube video out of sheer frustration explaining the easiest way to do this for a buddy of mine.

If I sound annoyed it's because I'd been through this with him on the phone like a dozen times and made the video to just send him, so I didn't keep going round and round saying the same things over and over. LOL It's my day off I'm trying to do as little as possible but appear busy enough people will leave me alone and enjoy a few cold snacks in the process.

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Should have said 3-4 full revolutions forgetting that the cam is half the crank speed and you need to ensure it's been gone over several times to make sure you didn't miss one at some point in the process.

 

[Sgt Gus]

I just made a YouTube video out of sheer frustration explaining the easiest way to do this for a buddy of mine.

If I sound annoyed it's because I'd been through this with him on the phone like a dozen times and made the video to just send him, so I didn't keep going round and round saying the same things over and over. LOL It's my day off I'm trying to do as little as possible but appear busy enough people will leave me alone and enjoy a few cold snacks in the process.

xc_hide_links_from_guests_guests_error_hide_media

Should have said 3-4 full revolutions forgetting that the cam is half the crank speed and you need to ensure it's been gone over several times to make sure you didn't miss one at some point in the process.

Lol, I hear your frustration. Thanks for that though Brother! Makes sense, I've watched the piston by piston method. We're fixing to replace our hydraulic lifters. Question...
After your 1/2 turn, to lock down the polylocks, are you holding the polylock still, or turning with the Allen screw? Thx! Never done it.

 

[nvrenuf]

Once you’re done adjusting, hold the poly lock nut still with a wrench and tighten the Allen set screw - not crazy tight or you’ll split the nut. The set screw prevents the nut from loosening.

 

[Turbo4whl]

but then as the engine starts warming up there's also the sound of a light metallic scraping noise that comes louder and louder.

Scraping noise could be the timing chain, water pump or push rods. About the push rods, those 454's could have one of 3 different diameter push rods. The push rod guide plates need to be the right size. Some of the cast heads may have a smaller hole cast in the head where the push rod goes through. The other issue, if the stamped steel rockers are a higher ratio, the parts may not all play nice together.

Look close where the push rods go through the guide plates and the cast holes in the head. See any scrape marks?

 

[xm20k]

Lol, I hear your frustration. Thanks for that though Brother! Makes sense, I've watched the piston by piston method. We're fixing to replace our hydraulic lifters. Question...
After your 1/2 turn, to lock down the polylocks, are you holding the polylock still, or turning with the Allen screw? Thx! Never done it.

Do the half turn with your wrench hold it in place and crank down the set screw with the allen wrench the half turn is the preload you want to keep that consistent and just jam it in place with the setscrew.

 

[bucket]

I'm not fond of relying on the little set screw to keep the adjustment. I prefer to get the adjustment almost tight enough, snug up the set screw, then tighten the nut further to get it locked in place.

 

[xm20k]

I'm not fond of relying on the little set screw to keep the adjustment. I prefer to get the adjustment almost tight enough, snug up the set screw, then tighten the nut further to get it locked in place.

Ya you could go short of half turn say 2/3rds of the way set the screw and finish the half turn to really mash it on there, however the cheaper poly locks might not take that, so I tend not to suggest that.

But then again, I tend to not buy cheap valve train parts and size up on what I can, 7/16 studs instead of 3/8, 3/8 pushrods vs 5/16, stainless rockers over aluminum etc.

 

[bucket]

Ya you could go short of half turn say 2/3rds of the way set the screw and finish the half turn to really mash it on there, however the cheaper poly locks might not take that, so I tend not to suggest that.

But then again, I tend to not buy cheap valve train parts and size up on what I can, 7/16 studs instead of 3/8, 3/8 pushrods vs 5/16, stainless rockers over aluminum etc.

Yeah, I wouldn't want to go cheap on poly locks. Would just assume to keep factory stuff in that case.