Rod Bearings Top & Bottom

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Ready to install my rod bearings, Clevite CB-481 P. But then I noticed one half was marked with a M or possibly a sideways E and a 1-12. The other side has no M and is marked 1-13. To me this must mean there is one half for the cap and the other for the rod. Is this correct?
 
hi, they can fit either cap or rod. usually , they will be marked top and bottom. I just looked at mine,to double check. no markings. install them.
 
Look the same side by side other than the markings.


The one on the right is marked 1-12 and no M (second pic). If they are not different then why the different markings?


Sorry about the bad pics. Cell phone.
 

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Are you using stock rods?


Those bearings don't have the "notch" for the oil squirt hole for the stock rods. There are bearings available for the squirt holes.


Some aftermarket rods do not have the squirt hole and those bearings will work fine for them.


You have to pay attention to the Main Bearings. Some bearing sets only have holes in the top bearing shell for the oil passages and none on the bottom. If you put the bottom shell in the top hole, then you block the oil from getting up to the cam and top of the engine. For main bearings, the shell with the hole goes into the block, the one without the hole goes in the cap.

For the rod bearings with the squirt hole, it doesn't matter as the notch is opposite the anchor slot and is in the center of the parting line for both shells.
 
Could be they are marked differently because they were built in different batches, Jan 2012 and Jan 2013.

The notches can be added, and should for a street motor. Given modern oils having lower anti-scuff package (ZDDP) levels, it's more important that the cam keeps wet, especially at lower RPM.

The notches went away with the magnum engine primarily for fuel economy and emission reasons. Reducing the amount of oil on the cylinder walls allows a lower tension ring package to be used. Less internal friction=better MPG. Also any oil passing the rings and getting into the chamber will end up in the catalyst causing it to overheat and melt down. The industry standard is 8-80 warranty on emission control equipment so it's worth the manufacturers while to make sure that spendy little bugger lasts through the warranty.
 
These are for a 96 5.9 magnum motor. Do I have the wrong bearings then? Got them all as a package from the machine shop - cam, rod and main bearings. Also was looking at my old rod bearings and they also had different numbers 8 of one and 8 of another.
 
If you're doing a magnum motor there's no need for the oil notch, those bearings are fine. The magnum has a roller cam which is a lot less oil sensitive.
 
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