While helping a buddy rebuild his d16 we managed to get all the rod caps mixed up. They were marked with masking tape but the oil washed off the marks so now we're stuck trying to figure out how to get them back together. I know for sure that the arrows were pointing toward the pulley side when I put it together and that they went back exactly where they came from. On the rod caps from rods 1 - 4 It was marked (3,4,3,3). I've read about the magnifying glass on a few forums but I gave that a try and can't see any specific machine marks. I'm curious about the stamps on the top of the rod caps, is there supposed to be a pattern? Rods 1 - 4 it looks like it's facing right, left, right, left. If there is supposed to be a pattern then I'd only have to worry about rods 1 and 3. I'm really confused but if anyone have any suggestions I'd really appreciate it before we have to go salvage some rods with matching caps at the junk. Thanks

 

You could always take the rods out, then take each rod (i.e. rod #1), torque the unknown caps onto it, and measure the diameter at various spots like 45*/90*/135*. If it's the wrong cap the diameter will probably be measurably wrong and/or inconsistent, and if it's the right cap the diameter will be correct and the same at every angle. Also, when you finally get them matched up right take a punch and mark both the rods and caps on the intake side (or the exhaust side, your choice) with something like .|. : .:. ::: so you will always know which is which in the future.

 

Thanks tjbizzo, perfect. In case anyone runs into this thread, I used a digital caliper and checked every 45 degrees. Only issue I had was trying to keep the caliper tight so I can a good reading, wiggling back and forth slightly will do. It becomes pretty obvious after 3 checks if its the wrong cap.