It is good to hear your positive comments about that shop.
Respectfully, “machining ability” starts with learning how to measure properly; continues with caring for precision tooling; and ends in a quality finished product with proper fit, form, and function.
In an ISO/AS9100 (International Organization for Standardizations/Aerospace) environment, all measuring tools used for inspection purposes are required to be certified once (minimum) within a year. Some shops that I have worked in take it upon themselves to send all tools out ever quarter for certification because of the tight tolerances they work with. Documentation on all tools needs to be maintained. Some customers even require recording of the serial number of the tool used to measure the feature in the inspection report.
I know that automotive shops are not held to that standard, however it would be nice to know that they at least check their tools for accuracy.
I had a Mopar crankshaft worked by Lunati. When I received that crankshaft, every journal was exactly .010 under nominal size to the tenth (.0001). I could not measure any variation anywhere on that crankshaft. Again, I purchased a Crower BBC crankshaft and when I inspected it, it was dead center in the middle of the tolerance to the tenth per the Chevy Power book. I purchased a new SBC crankshaft from a local (highly recommended) shop. When I received it, it had damage on some of the mains. That highly recommended shop then sent my crank out to another highly reputable crank grinder. When I received the crank, the mains were .0135 to .0155 under the minimum diameter specified in the Chevy Power book. The mains also had .001 of taper over the width of the bearing surface. I took it all back to him and said, again, “It aint right!” I was then told, “You measured it wrong.” I asked him to measure it with HIS tools to show me my error, but he would NOT. Since I had to carry my now worthless junk out of the back of his shop, I now understand why. Once I got behind the beautiful storefront facade, what I saw was a workbench with heads and intakes piled on it, and buried in that pile was a couple micrometers and a Sunnen dial bore gage. That Sunnen dial bore gage cost at least $600, how could somebody be so careless to just throw it on the bench piled with junk. If he can’t take care of his own tools, how can he do quality work? This was reflected in the quality of work that I received. The funny thing is, a sign hanging in the storefront read, “Long after price is forgotten, quality remains!”
Ultimately, it is your money and your project, and I want you to be happy and successful. I would also like to know about quality shops and quality workmanship. I hope that that shop turns out to be such a shop. Good luck with your project.
Cheers,
Joe
