Rod bearing caps switched..

[FLUX]

So I am currently in the process of honing my cylinders and replacing the piston rings on my engine. (1977 l20b 620) I remove the oil pan, remove the sump pickup and start to remove the rod bearing caps one at a  time. I noticed that each one has the number four stamped on one side and the number of the cylinder it belongs in on the other side. I get to cylinder three and it has the rod cap from cylinder number four and vise versa.... So basically the rod bearing caps in cylinder three and four have been switched at some point in it's life. The rod bearings themselves are NISSAN branded and are standard size, so they have probably never been replaced. They are NOT showing any copper and don't look that bad at all. My question is should I leave the caps where they were or return them to the proper cylinders??

[datzenmike]

Do both the 3 and 4 cap and the rod have a number 4 on it??? If so I wouldn't worry about it. To be sure plastigauge them.

[DanielC]

Keep the cap with the rod it came off of!

 

The connecting rods are assembled with the rod cap in place.  Then the bore for the crankshaft is honed to size, taking in account the bearing thickness, and then the rods are taken apart, bearings installed, and put back in the engine.  If the bearings show no abnormal wear, that is the correct place for the rod caps.

 

Like King Rat said, plastigauge them.   I would also assemble your engine from the back, put #4 piston in,  turn the engine, put #3 in, turn the engine again, and make sure the engine does not get abnormally hard to turn as you assemble it.

[FLUX]

Yes, all four rods and caps have fours on them. I figured I should leave them where they are at since they've been there for a long enough time without anything happening! Thanks!