I need a set of rod bearings for my 408 stroker. The kit I bought in 2001 came with Clevite 77's. I just opened the packages and 4 of the 8 are defective. They are brown, look burnt, with blueing around the edges.

Im afraid to use them and need to order another set. The ones I have are CB-481-H Summit lists 2 a CB481HN and CB481HXN, Can anyone tell me what the difference is? Any recommendations are appreciated.
Scott

The NIB bearings were used

I dont think so, they came from a reputable shop, and there is no sign of wear, its hard to see in the pics but it looks like they were overheated during manufacturing. Some of the brown comes off with carb cleaner, its not oil, more like a varnish. Very strange.

Sounds like some residue on the bearing rather than defective bearings. You could (though I'm not necessarily recommending it) take some fine scotch brite and lightly buff the bearing face while under a stream of CLEAN solvent in your solvent tank. It takes a bit of rubbing to take off an appreciable amount so don't be afraid you're going to ruin the bearing (though it can be done so be careful if you try this). If the bearing face shines up, call it good. If the material doesn't appear to be flaking off then the bluing on the bearing shell is most likely caused by the heat using during the bonding of the bearing material.
And the X in the 481 hxn is for extra clearance. Using both halves of the HXN bearings should give you .001" MORE bearing clearance. If you only needed half a thou you could mix standard 481hn's with 481hxn's and you'd be there. If your crank was slightly undersized you could get 481hn1's which would give you approximately .001" LESS bearing clearance. Since you have a new crank, you should not need those. In fact, I would use the bearings you have to check the clearance and then decide which bearings to get. Whether the std's or the X's.

Thanks, if it was just the residue I might try it. There are some with the blueing just right at the bearing edge. Its not worth the risk. Thanks for the info on the part numbers, and the tip on checking them all first with the bearings that I have, at least if some need adjustment I can order what I need.
Scott

Dodgeboy
What is the difference in the part numbers CB481H that I have and CB481HN that I can order now? 4 of the 8 look good so I really just need to buy four if they are still the same.

H bearings have a chamfer, they have been phased out & replaced with a narrower bearing designated HN

Be very careful when installing them to be sure the shells mate properly with the narrowed side to the radiused area of the crankshaft...

Are all currently available bearings the narrow design? I guess I should replace the entire set and not mix the 4 good camfered ones with the new narrow ones.
Scott

I spoke to the place I bought the kit from and my local machine shop, apparantly this discoloration is normal for a high performance bearing and there is nothing wrong with them.

Scott

Nothing wrong with them. that's how they come. However, if you have a cast crank, you might want the HN bearings. Otherwise you may find you have no rod side clearance.