supraguy@aol;1934167 said:
If the mains are true to the block and there was no debris under the bearing, then its probably a crank journal with a touch of taper. Thats assuming this is a main bearing. If its a rod bearing, it could also be a bad rod.
SupraPieces;1934283 said:
Could it have been cause by blocked oiling holes on the crank? I saw this once before on a motor I parted out and am just curious
The oil filter proved that the machine shop did NOT clean the crank properly and there was debris (metal shavings) inside the crank. I made the rookie mistake of trusting the shop and installed the crank with minimal cleaning.
Besides microscopic dust, there was absolutely no debris under the bearings. I'm a very thorough individual and I measured everything w/ plastigauges 3 times. Everything was torqued properly and my Snap-On torque wrench cost me $575, so I'm assuming that was good and properly calibrated. I also checked torque specs while removing the bolts and it was consistent throughout. That tells me that it was not an improperly torqued rod or main cap.
I'm leaning towards what Suprapieces has suggested that the metal shavings in the crank clogged the oil hole and once released, it scratched the bearing. Another pointer here is that the rod bearings are completely fine from what I recall. Will have to check again.
I'm now concerned about the right side of the bearing bearing being worn out more than the left. I'm not sure if this is a result of what I described above or that the crank journals were not cut properly or the bore on the block is off.
I'm planning on putting new Clevite 77 (NDC) bearings and ARP main studs. The rods already have ARP rod bolts.
This engine is not being built for high HP or racing and in the short life it had it was never redlined. I just want to make sure that it can be reliable and that it would take some abuse if needed.
If anyone had a similar experience with bearings, please let me know what your findings were. I'll try to post a picture of all bearings this weekend. I didn't get to take them all out yet.