Engine knock and bad bearing

[MAC71]

On my way home from work on Friday the engine started making a knocking and rattling sound. It starts around 2000 rpm and is coming from the lower right side of the engine around cylinder #2. Pulled the engine out and it looks like #2 bearing is the issue.


Rod bearing #2



What the other rod bearings look like


Main bearings


The crank has groves and has .030 bearings in it so may have to find a different crank.

[snj8198]

Awe that sucks. What are your plans and budget for the rebuild?

[hamjet]

Dont see any signs of the bearing spinning on the rod, wonder why it started knocking all the sudden? looks like the babbits wiped off the one rod bearing thow. Sorry to hear that. Really sucks...

[MAC71]

The #2 cap side of the bearing was also like the ride side. The rod bearing that was not wiped out is how the other 7 rod bearings look.
I did not build the engine and it came out of a truck I bought a few months ago that I am using as a daily driver, it's a 69 c20 camper special. It is a .030 over block with no ridge. I am on a tight budget with this as I am restoring my 71 c10 right now. I think I am going to take the crank to a machine shop on Monday and see if it can be turned and have them resize that one rod. Than reassemble with new bearings.

[mechanicalman]

Originally Posted by MAC71

The #2 cap side of the bearing was also like the ride side. The rod bearing that was not wiped out is how the other 7 rod bearings look.
I did not build the engine and it came out of a truck I bought a few months ago that I am using as a daily driver, it's a 69 c20 camper special. It is a .030 over block with no ridge. I am on a tight budget with this as I am restoring my 71 c10 right now. I think I am going to take the crank to a machine shop on Monday and see if it can be turned and have them resize that one rod. Than reassemble with new bearings.

It looks like some abrasive substance has went through the oil. I'd cut the oil filter open and see what is in there besides bearing material. Inspect the cam/lifters do not mix up the lifters.

What does the top of the piston on the failed rod bearing look like, and also the flat surface of the cylinder head on the same cylinder?

I'm sorry but I think you may need to remove the cam bearings, oil galley plugs, have the block tanked and new cam bearings/galley plugs installed.

Dis-assemble, clean the oil pump, including the pressure regulator piston.

If the rings are good you should be able to re-use them without honing, boring, or glaze breaking. Try not to rotate them from where they came out of the engine, otherwise mark their orientation relative to the piston.

Check the wrist pins for excessive wear.

Make sure new rod bolts are installed on the failed rod bearing rod. Consider doing all 8 rods with all new bolts.

Saving money can sometimes cost you more money.

[GRX]

^^ good advice right there.