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Author Topic:   Any ideas on what caused this.
posted March 02, 2004 07:22 AM
Does your rear cap have the oil pump hole all the way through? Does the bolt hit the back of the bearing? I've seen motors wipe out the rear main 'cause the wrong bolt (GM used 2 or 3 for the different caps. Some had the whole all the way through, some are blind holes) was used. The difference is only like 1/8" or sumthing but could cause the rear main to distort.

Just a thought.

posted March 02, 2004 11:26 AM
hard to tell by picture but was the crank wearing the bearging? Looks like you can stil see the radial grooves from when the brg was new. If beargings are racing beargings that may have been the color that they where when new. I know our Federal mogul race brgs where a brownish kinda mixed color. Hope this helps

Josh K.

posted March 02, 2004 04:10 PM
It really looks like the oil pump bolt put unnessary stress againt the bearing be sure that you touqued to specs also make sure that you areusing the right bolt


rico 08
posted March 02, 2004 04:19 PM
did you check the clearance?Looks like a really loose bearing clearance

posted March 02, 2004 05:21 PM
Do you know if the engine was line bored or honed?When you do either we cut an old oil pump off and leave the mounting pad so you can torque it like the oil pump is on the block.It can cause the bearing to wear in the center or heat up because the cap can flex enough to wear wrong in some cases.It is kind of like boring a cylinder without honing plates.When you torque the head down without honing plates you can see the stripe marks on the cylinders from the pull of the bolt.We tried this to make sure it was worth buying all the plates.

posted March 02, 2004 08:04 PM
If there h bearings mine looked that way right out of the box.find out what they are if you didn't put them in yourself

posted March 03, 2004 05:51 AM
Yes this engine was line bored. The center of the burn pattern is off to the side of the oil pump bolt hole.

Could there been a high spot on the bearing making it defective?

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