Crankshaft journal surface

Had to replace a crankshaft recently. Bought one from a jeep repair shop in Denver. Just got ready to install it and noticed that there are some small "pits" in the surface of center main and 4th cylinder.

These are visible and you can feel them but otherwise the journal surface looks good.

They are not perfect. How imperfect is ok? I don't want to install if they are just going to fail my bearings again.

 

Picture? I would think that a pit with no raised metal will be fine just another place for oil to pool.

 

Cast cranks often have pits in them. Mine had pits in them that were simply voids from the foundry. If they are small, say no more than .030" across they should be fine so long as there are no burrs on them.

 

I presume this is not for your F134?

 

If this is for a 134 than it has a forged crank and there should be no pin holes or voids.

 

It is for my F 134. There are no burrs or raised edges. It's not perfect for sure, I'm getting so I expect perfection from the machine shop though. This whole engine thing has been a long disappointing story. Anyway I'm ready to install... except for the pits. I'm just frustrated that nobody can do a job right anymore. If I produced work like I've been seeing I'd be fired... and should be.

So a general consensus is that if it's not a rough raised surface it should be ok...???

I just want the engine to run, and reliably so for a few years.

 

Hard to say how rough it is from your description. Apparently there is a roughness measure called "RA" which will indicate the fineness of the finish. This article http://www.aa1car.com/library/cpolish.htm indicates that OEM crankshafts are polished to RA of 8-12, with a tape grit that's roughly (pun intended) the same as 600 sandpaper. So, I'd guess if you can improve the finish with a strip of #600 WOD emery paper, the finish is overly rough.

Do you think that these pits are machining artifacts or something in the casting? I'd think if you can feel them, they are unacceptably large.

 

I've re-built two 134's and one 225 and I've never seen roughness or pits on a re-ground crank.

 

I had a crankshaft of a rare motor repaired at a local shop that usually does marine diesel motors. The crankshaft had to be flame sprayed and ground down. It had several areas with very small pits. When I asked them about it they said that the flame spray was hard and was also a little porous. They claimed that it would also help retain oil and that no engine life would be lost, I had no problems. If you can, you might at least give them a chance to comment on their work.
Good luck.