with about any performance cam that you might install, compression will not start until about 50/60 degrees AFTER bottom dead center, when the intake valve finally closes, according to the advertised specs. Thus pits in the zone of more than 3.315 from the top of the piston, are inconsequential to making pressure.
With an Ica of 55* the Effective stroke is 2.76.
By 60* the E-stroke is down to 2.66. and
by 65* it is just 2.54.
At say 2.66 Effective(60*Ica), from 3.315, that is .655inch, from the bottom of the area that is swept by the rings, where there ain't no compressing going on.
If your pistons come to Zero deck, this means any pits below ~2.66 from the deck, are meaningless.
Pits above that, could however, affect the bottom of the intake stroke, (mostly meaningless by this time) but, potentially, could trap oil that could lead to detonation, depending on your compression ratio, and the amount of oil entering the combustion chamber.
I'll wager that the pits are from water sitting on the top of the piston while in storage. If the piston was at the bottom of the stroke, the pits would be at about 3.315 plus the deck height plus the crevice distance so let's estimate the bottom of the pit at 3.62 from the deck going to perhaps 3.5 from the deck. That would be a non-issue.
But if the pit is up closer to 1 inch from the deck, that might have the potential to hurt, as the pressure scoots by first the top ring then the second. However, Firstly; this is only gonna be for a couple of crankshaft degrees and once the rpm gets up, this will only be for micro-seconds. And secondly, not much oil is gonna get up to that pit cuz the squirters will never really get to it.
So, IDK, it's sortof a judgement call, based on where exactly the pit is.
But if your machinist thinks another .020 will clean it up, Ima thinking to pretend I never saw it, no matter where it is; thats my judgement, lol.
