Oil system myths

yellow rose said

The second was about lubrication for the timing chain. He pointed out several OEM’s are now specifying pumps that have a built in spray hole to put direct pressure oil on the timing set. He mentioned the OE’s doing it and I don’t recall exactly which engines they were but IIRC one was the late model Hemi.

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I don't know about the V-8 mopars (can't remember)but the slant six did have pressure oiling to the timing chain from the factory.The factory number 1 main bearing had a 45 degree champher on the parting line of the upper bearing shell. Oil sprayed out this channel directly on the chain/slinger. I have never seen a after market replacement bearing with the champher. I always put the champher on that bearing if not using OEM bearings. This can be proven by the fact, that the oem bearings had a different part number for #1 then for #2 and #4. The after market bearings have the same part number for all three locations.

Edit: Just did some checking and the big blocks had the same "oiling" champher on the #1 upper main bearing shell. I did not find any referance of this on the small blocks.