I agree. You can always add errors and compromise to any machining process. From the factory these things had tolerances all over the map.
I’ve never checked it (because the fix is worse than the disease) but I’m betting it you lined up 10 brand new OE blocks and measured cam to crank distance they’d all be different and Id bet good money that some wouldn’t be within blueprint specs.
I always line hone everything. If the crank needs a grind I size the bore to minimum (or a few tenths under), snap the bearing in there and measure the bore. Then I tell the crank grinder where I want the mains, even if it’s UNDER a minimum. I leave the hole a few tenths under in case the guy grinding the crank misses and gets the crank big. Then I can take a bit out and still be on the low side of the bearing bore and get my clearances.
I’m not into using different size bearings to get clearance. Drives me nuts.
If you aren’t using the line hone to set your clearance you are swapping bearings or you have to let it be what it be. I’d rather know what I have, with straight round holes then to save a bit of money.
