So, I'm replacing valve stem seals in my '79 L48, and the #3 intake valve looks like some kind of gorilla has been beating it with a hammer for hours. I was able to get the keepers out and replace the seals without too much trouble after carefully polishing the burr off.

When I bought it one of the rockers was tapping badly and I adjusted them all when I got it home, but I have never had the rockers off before. I have driven it for 15k+ since then with no trouble. Can I assume that, while obviously not ideal, I can just continue to run the engine like this with no issues? Or is this a compelling reason to pull the heads off and replace the valve?

Money is tight right now and I am looking at a 383 crate engine in the next couple years anyway, so I'd prefer not to put much more cash/parts into this engine. Thoughts?

 

This could've been the one that was tapping badly and this is the result. It's possible that if the lash is kept in check, it'll run a long time with no issue. Just keep an eye on it.

 

I would tend to agree with this. Monitored it will likely run fine in that condition. If you were running 500#'s open pressure it might be a different story. Stock springs with flat tappet cam run a relatively low spring pressure.

 

I would replace the rocker and make sure the valve stem top is as smooth as possible, no burrs.

 

Well, I did the other side today and found another damaged valve. No pics this time, but it is worse. The valve stem on #4 intake has been hammered down so much that the keepers were bent as well.

I put it back together and ran it, and got all the lifters adjusted. Then I went for a drive, and it blew up. The noise made me think it dropped a valve, but that is not the case. All the valves are in place and the rocker nuts still feel properly tightened (ie no rockers flopping around or anything like that). The #4 exhaust pushrod was sitting much lower than it should have been, however.

Pulling the intake revealed that the #4 exhaust lifter has a missing retainer clip, and the top dished portion of the lifter (not sure what its called?) was sitting in the bottom of the lifter valley. I have no idea how this could have happened, unless I had the rocker on that pushrod way too loose. Is that a thing that could cause this? If not, what could?

Last question is where to go from here. Do I get a new clip and put the engine back together with the old lifter? Replace just the one bad one? New cam and all new lifters? Maybe pull the heads and see if anything else is worn/broken?

Motor is an L48 with supposedly ~100k on it if that matters. It has a weiand intake of some kind, and I dont know if anything else has been changed.

 

Too bad about your engine. With that mileage, I would do a complete re-build or consider a crate replacement.

 

Edit: I misread your reply, and thought you were asking about the mileage. I got it now.

About 100k, I think. History is really unknown. It ran ok until I started messing with it, other than burning oil and fouling the #1 and 3 spark plugs after a few hundred miles (hence the seal replacements). I dont think there is anything really wrong with the bottom end or the heads, but IDK. As far as I can tell its just a bad lifter

 

All these things together sound like loss of valve control. The springs are not right for the cam or they are fatigued and cannot control the valve movement.
Check all the valve stems. The one that is hammered down to the locks I would consider unservicable. You may end up dropping a valve and that will cause significant damage.

 

See if you can find a running 350 on craigslist or something and pop it in......I see them all of the time here.....of course you would have to pop the heads off and check things out but it is a cheap alternative.....

Jebby