The idea behind the lubro-moly is that it builds a layer of slippery molybdenum on all internal parts, including the upper valve train. So even the upper parts of the engine have lubrication in those critical few seconds at cold starts before the oil reaches up there. I don't doubt there may be an issue with the size of some oil galleries that prevent good flow till the oil thins, all I know is that for me I was able to severely reduce the knock to what I would call normal for any car by using this oil additive.
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