Shavings in oil pan that are not metal

[1970 skylark 350]

The engine doesn't knock John. Could that also be a sign that maybe it is a cam bearing issue? If it is worn cam bearings, is it possible to replace the cam bearings if the other bearings are not shot?

Or should the entire engine undergo an overhaul? It would be a shame if the entire engine had to be rebuilt over worn out cam bearings.

I guess I need to make the examinations you suggested first and pinpoint the issue.

[TexasJohn55]

If no cam bearings spin and there is not evidence of heat or discoloration around any of them, they are likely OK. Cam bearings usually have to be sized when installed as you may have a tight one even when new ones are installed. Consider it rare to drive in a new set and the cam spin freely.

If any main bearings are failed, they may not knock. Evidence of a main failure should be visible at the edges of the bearing at the cap. The bearing will not be fully visible without numerous rotations of crank to give the best view of each side. There should not be any discoloration of any caps and the bearing mating area at the cap and crank should be clean and crisp without any "flaring" of the bearing surface where it meets the crank. If any main bearings are seen to rotate with the crank, it is failed and stuck to the crank and I would expect you to find more metal and maybe even cast iron "powder" which would stick to the magnet.

It is entirely possible that you do NOT find any bearing failure, but it is still prudent that you at least inspect it as best you know how without replacing all the rod and main bearings.

So, inspect cam bearings first, when satisfied none have spun, check crank end play with feeler guage, if ok, then inspect main bearings and caps as mentioned above. Drop main caps that look suspicious. As you said, a rod bearing would likely knock but look at each cap to be sure none are discolored from heat.

If you know anyone with alot of engine experience, a second set of trained eyes would be useful.

[1970 skylark 350]

Well so far I have not found anything yet. I had a friend rotate the crank shaft while I looked around for a locked cam bearing. I didn't see anything. It was pretty clean too.

I checked underneath for heat spots and shavings and uneven bearing edges. Nothing. Everything is surprisingly clean for an engine this old. There is a little windage tray towards the back of the crank train. I am going to take it off and see if there is any shavings on the top of the tray and see if I find anything glaring around any other bearing caps.

I'm tempted to remove a cap, but I don't want to disturb anything.


A Buick friend of mine thinks I have nothing to worry about. He says when the pan is removed for the first time on such an old engine, there is bound to be some debris. He says if the oil light doesn't come on at hot idle, it can't be too bad.


I'm going to spend some more time on this inspection before I am confident I can go ahead and put it back together and continue to run it.

I wonder if this oil pan debris is something that was a by product of when the engine was manufactured. I have yet to find any of this elsewhere in the engine.

I cut the oil filter open and the pleats were clear of any shavings or particles. It wasn't really very dirty either. It seemed normal.

[TexasJohn55]

That is good news so far, maybe you can check crankshaft end play and put it back together.

[bob k. mando]

you know what this really calls for?

engine oil analysis.

http://www.blackstone-labs.com/

then you'll know exactly what is in the oil. i should think you'd be able to send discrete samples of the mystery solids as well, but you'd need to call them and ask.


i suppose you've already thrown away the waste engine oil?