I'll weigh in on the question of clearance. I think "tolerance" is the
wrong word here.
The shop that did the bearing work on my 5.0L ford engine for my Cobra
replica selected bearings individually for each journal to give me
greater clearance than the middle or low end of the tolerance range, his
premise being that an engine being pushed harder develops more heat and
should have proportionally greater clearance at cold. He builds lots of
race engines.
Larry Colen wrote:
>When Armando did my crank, he machined the rod journals to tighter
>than stock tolerance, and told me to use thinner oil. The premise
>being that with the blower, the tighter tolerances will allow less
>room for the rods to pound on the crank.
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