Lou64

'64 w/ L-75 engine

Took off the oil pan today to replace the gasket, saw some very sharp and worn edges on the crank. Is this
A) totally normal
B) concerning
C) need for rebuild very soon

The bottom side of the pistons and the cylinders look impeccable--I can see where someone wrote the cylinder numbers on the bottom of the pistons in pencil (am wondering if they are replacements) and cam looks great too. I think the engine was rebuilt in the mid or late 80's and only driven a hundred miles a year (until I got it in 2010).

pop23235

"B" Can't tell a lot from pics, but don't remember seeing that before. Maybe the crank has a troubled past?

BADBIRDCAGE

If you are referring to the shiny areas on the crankshaft counterweights thise areas are not wear areas and are normal in appearance. The countersunk area on the counterweight could be from a balance job.

I don't see anything abnormal.

Pop Chevy

Those are machining marks --normal--run it !

pop23235

Well, it's obviously running now. And no metal found in the crankcase. Didn't mention noises or vibration, so no problem now. Just never have seen the first pic. Looks like a piece missing on the counterweight right by where the factory drilled to balance. On the second pic, that strange bright area shows machine tool marks, so it's intentional, not accidental or interference. Just as I said, maybe the crank has a shady past, not in this configuration. Yeah, I'd run it, but I'd be concerned with why, if I'm seeing the pics correct.

Lou64

Ok, so to follow up, the first pic where you see the shiny area and above it, the edge is very sharp and it doesn't show in the pic but it looks like jagged and has some metal bits hanging on, very unlike the other weights (is this their proper name?)

wmf62

if the engine runs fine (no vibration), then when you rotate the crank and you don't see anywhere that the counterweight(s) may have hit, don't worry about it. if the "jagged/sharp" part concerns you, use a grease covered file (greased to collect metal) and lightly remove the edge.
Bill