[gtofreek]

Here are pics of the bearing tuneup. The first pic is of a bearing after I lightly filed the back with a fine file to show high spots. If you look at the outside edges, you will notice they are shiny and black right next to them. The black is a low spot and the shiny is a high spot. The high spot on the outside edge is roughly sticking up about .001". This pushes the bearing into the crank when assembled. If you were to assemble this without doing anything, turn the engine over a few times and remove the rod cap, you would see the outside edges of the bearing would be shiny from rubbing on the crank. By filing the high spots away, this does not happen and the bearings are much happier. After filing I sand the back real nice with fine wet/dry sandpaper and scotchbrite the bearing surface. The same holds true for the main bearings, however, the back side of the flange bearing has a protrusion of the back out near the flange. This protrusion is about .150"-.200" wide, coming out from the flange. This is caused from manufacturing processes. The protrusion also shoves the outside edge of the bearing into the crank. There again when you run a file across the back, you can see what I'm talking about. I file this protrusion down flush with the rest of the back and file good over the stamped numbers as they have high spots around them also. Then I sand it good.

Everyone says you have to run oil restrictors in the lifter bores to keep from burning up the mains, but I do this and never use restrictors and never have bearing problems. I have large 455 journal engines out there running over 7000 rpm for years also, so I believe this mod helps tremendously for bearing life and cooling.

By cleaning up the back and getting rid of the high spots, it gives more contact area with the rod and the bearing can get rid of heat more efficiently. Also, I believe the fine scratch's on the back also help it grab ahold of the rod. Doing this only reduces the thickness of the bearing by .0001". I have never had a bearing failure in any of the hundreds of engines I have done this to.

The last pic of the thrust bearing shows the mod I do to feed pressurized oil to the rear side of the bearing[the chamfer on one side, at the parting line]. The group of rod bearings shows the holes we had to bore in the lower bearings for the aluminum rod caps. The group of main bearings are done and ready to install.