Too many peaks/valleys microburrs on crank&lack of edge in camfer in L87=Massive Failure GM engine as too many oil pressure waves

 https://www.youtube.com/watch?v=zglEmlYAu04

Wow - just because the crank was made with too much angle in the too big chamfer in the oil bearing holes - it caused too many peaks/valleys in the crank and therefore cause the oil to have too many pressure waves in the rod bearing and thus loss of oil pressure....

You want the oil pressure wave to stay ramped up, you don't want it to fall off...if you don't have that sharp edge for that wave to come out of there - it just kind flattens out....

 So the RZ [five extremes] is supposed to be six times max of RA aka "roughness average" but in the L87 it's ten times over! So there's too many "valleys" and "peaks" and this causes loss of oil pressure...

You can barely see this with the naked eye - it is super fine engineering precision.

 GM received over 28,000 complaints for its L87 V8 engines by early 2025, with about half (14,332) involving loss of propulsion, leading to a major recall and ongoing investigations by the Autopian and the NHTSA for manufacturing flaws causing bearing/crankshaft damage. GM expected about 3% (around 18,000) of recalled engines to need replacement, but the broader issue affects hundreds of thousands of vehicles across Silverado, Sierra, Tahoe, Suburban, Yukon, and Escalade models