Technical SBC minor engine shrapnel id (what was it?)

I have the rocker covers and intake off, doing some cleaning up because removing the intake dumped some coolant in the valley and around the valvesprings. Cleaning the tops of the heads around the valvesprings, I found some metal and rubber bits.




The silver bits are metal, pretty hard. Can’t easily bend them. The darker bits are rubber. On the right, these were found in the area around the rear most head bolt on the passenger side. The bits on the left were around the rear head bolt on the driver side.

Anybody got a guess as to what these were? The metal bits are similar enough to each other that they seem like they were once a single part. The rubber bits could be anything.

I have the oil pan off too, there’s no debris down there.



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Valve seal.

 

How big are they? Valve seals?

 

Should be about the diameter of a Nickel, or just slightly larger.

Once the rubber lets go, it will flatten out.

 

That looks about right. Thanks Gimpy. Good thing it’s already this far apart. I’ll get some new seals in there while I’m at it.


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Those metal pieces look like the seal retainer rings.... Woh!....

 

"Minor'' and ''engine shrapnel'' have never appeared in a sentence together before.
Glad you caught it.

 

Check lift of cam you may be crushing them.

 

Take the oil pan off and clean it. I have had bits of the rubber seals get in the oil pump. Sometimes it just blocks the pump, sometimes it can get in the pump and jam it up.

 

Give the valley a good wash with solvent, make sure nothing is around the push rods and lifters. Short of taking it all apart this should do ya. Good call on dropping the pan and give it a new oil pump.

 

There's other chunks missing from your pictures.... Where are those??????

 

Wait until you look at your oil pump intake screen.
If your valve springs don't have machined seats in the heads you need some spring seat steel inserts.. You need to hold the valve spring bottom from moving...
This can also be fixed by running steel sided valve seals. They are made for triple springs but I run them on everything. Summit, Jegs, Competition Products, etc all sell them.

 

I lost an engine because of those bits, when the shop rebuilt my heads they installed those seals on the tapered guides that originally had umbrella seals, the PC seals expanded enough to make contact with the spring damper and about 10 of the shredded like you show.

 

I wasn’t sure how else to describe it. If I think of engine shrapnel, I picture something like



and clearly this isn’t as catastrophic as that. But broken metal bits are bad for engines. So, yeah, feeling kinda lucky, maybe. And glad that somebody long ago taught me to be picky, clean everything, and check everything you can. These were hiding in puddles of oil, and if I hadn’t decided to clean the area out, they’d still be there.




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Oil pan is already off, haven’t cleaned it yet, but that’s on the list before this goes back together. Right now there’s some oil still in it, along with some coolant from taking off the intake manifold. I didn’t see any debris when I took it off, but will be double checking that.



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Don’t know. They may be long gone.

Backing up, this started about a month ago. I had a hub failure on my DD, and with a one car garage, and weather that’s already running colder and snowier than normal, needed to get that fixed. So I backed my Chevy out, and pulled my DD in one evening after dinner. Swapped the hubs for new ones. About 11pm, done with the DD, I backed out again, and went to put the Chevy back in the garage.

Turned the key, engine started, but with a loud banging noise at about 1/4 engine RPM. Bang! Bang! Bang! So, I shut it off, and pushed it back up the driveway and in to the garage.

Didn’t know what I’d find, but Bang! is bad. Got the jack and stands out, and started pulling things apart. Oil pan first, checking to see if I’d lost a bearing or rod or something along those lines.



I poked around the bottom end, not finding much. I haven’t pulled off any of the caps, but the bearings and rods seem ok. There’s no vertical play in anything, and the side clearances are in spec for a basically stock SBC. The short block is out of a 74 Chevelle, and as far as I know, the bottom end has never been apart.

Moving up, I took off the drivers side valve cover, and found



Backing up further, I bought this car three years ago. I don’t know its history as well as if I’d built it myself. I’ve been working on it, learning its details, and changing it to suit my tastes. The odometer shows 80K miles, about 15K of those are mine. And this wasn’t a new short block when it went in, so I assume it has to be over 100K miles now.

It has always had what I now know to be valve noise, a ticking noise while running. I probably should have checked in to this sooner, but didn’t. Having found #3 off completely, I checked the others and all of the rockers were floppy loose. Like grab it and rotate it side to side 3/8” or so loose.

I pulled the passenger side cover and found the same thing. All of the rockers were floppy. To get the passenger side cover off, I had to remove the A/C compressor and its bracket, which let the coolant in to the intake valley. Discovered that when I suddenly found a puddle of coolant under the car (oil pan still off).

Which is how I got to this point



The intake manifold is off, and cleaned up. The valley and tops of the heads have been cleaned up. I was being picky, cleaning all of the oil and coolant out of the crevices and crannies, just because it’s the way I learned to work.

I had already gone around and set the lifter preload on all of the valves. I guess I’ll be doing that again. I bought a valvespring compressor yesterday. So the rockers and springs need to come off, and then I’ll see what’s in there, what’s damaged, missing, or worn or whatever.

While I’m at it, that A/C bracket got modified yesterday so the passenger side valve cover can be removed without disassembling the whole top side of the engine. And the 1980s big square aluminum valve covers are being replaced by some finned covers.




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These are stock SBC heads. The cam is a Crane Fireball II, hydraulic. With floppy loose rockers, I guess everything could have been moving around. I was just going to go with umbrella seals. Should I reconsider that? Now would be the time to change my mind if I should run something else.



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If anything, I have not been getting full cam lift, with too much play in the rockers for the hydraulic lifters to take up all of the lash.

I haven’t taken it out to verify it, but this is supposed to be the cam that’s in there.



With the lifter preload set, rotating the engine by hand, I don’t have anything hitting or binding, but will recheck that to be sure.



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Looks like you have a shroomed valve stem tip... I'd replace those heads with a pair of new ones.... The guides are probably shot also....

 

Can you say floating valves.

 

If umbrellas will fit at max lift and their od will clear id of damper/spring I would use them..

 

Time to back up a bit , first is what made that rocker jump off the valve ? Broken valve spring , bent pushrod , cam going flat ?. After you determine the cause there are other issues like the beat to hell Valve tip , exhaust rotaters. With roller tip rockers , why were " all the valves loose " ?

 

It looks like too much thread above the adjuster nuts, as if the lifter preload is excessive. Could you describe how you set the preload?

 

What made it jump off is unknown, other than being loose. Valvespring doesn’t look broken, but I haven’t removed it yet to confirm. Had to work this weekend, so haven’t been out to the garage since Thursday.

Pushrod is not bent. Checked that by taking it out and rolling it. No wobble or wiggle of the tip.

Cam lobes looked ok from what I could see from the bottom side of the engine. Now that the intake is off, I am going to remove the lifter and see if there’s any better view from the top side.

Why were they loose? That’s the real question. I don’t know. I didn’t build it. Until this, I hadn’t had the rocker covers off.



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Starting with them all loose (as found), spark plugs out, rotate the engine to TDC on cylinder 1.

Tighten adjuster nut while spinning the pushrod until it stops being easy to turn. 0 lash. Tighten adjuster nut a further 1/2 turn to set the preload.

Repeat for 8 4 3 6 5 7 2.

On a new assembly, this should be enough. But in rotating the engine around, by the time I got back to 1, it was loose again. Not as loose as before, but no longer 0 lash. Turning it further, all of them had lost preload to some degree. I went around again, setting all to 0 plus a half turn. And a 3rd time around. They now seem to stay preloaded, though I’ll be taking it all apart again to remove the springs.

I was thinking the lifters were still pumped up with oil, so the first time I set the preload, there would be little pressure on them, but in rotating the engine they would be exposed to pressure from the valvespring, which would have then forced them to retract.

I read somewhere that it’s difficult to set preload correctly on an engine that has been run, because the lifters may not fully retract. They recommended removing the lifter and retracting it in a vice before setting the preload. I think I did essentially this but using the valvesprings.

Thinking about it some more, could this have started with the lifters failing and collapsing? It’s have to be all 16 of them, which seems unlikely. I can’t otherwise explain the slop in the valvetrain, unless it was simply assembled wrong in the first place.




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If you're going to remove the valve springs to check the seals , why bother adjusting the valves now? No need for further speculation until you pull the springs and check the bottom of the lifters

 

Right. I already did the valves, before finding bits of seals. So now it has to come apart.



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The studs might be 'growing'...

 

When you put it back together leave the intake off so you can see the lifters. With both lifters for cylinder no. 1 on the heel of the cam tighten the adjustment nuts just until you cannot get any vertical movement of the pushrod. At that point the p/r seat of the lifter will still be against the retainer clip. Now you can give the nut another 1/2 turn, that will move the p/r seat away from the retainer approximately .020 establishing the correct preload.
Run through the rest of the lifters the same way and you are done. No need to adjust them any more, providing your rocker nuts still have enough built in friction that they retain your settings.

 

Would that be directed at me?