| such as a Sunnen SV-10. Ask them how close they can hold cylinder taper and out-of round. Ask them how they finish their cylinders? Do they use a diamond hone? Do they plateau hone as a final step? I also like a shop that has a Newen single point seat cutter. Otherwise a nice Serdi with a skilled operator will be ok. Single point cutters are less prone to seat chatter, however. Some shops claim they have equipment that they don't have. Ask for a tour of the shop. Treat this as if you are interviewing them for a job, because you are. Ask them how they verify valve seal. You should either buy or borrow the instruments needed to verify their work. A decent non-digital preferably non-china dial bore gauge and a set of micrometers. Or maybe have them measure cylinder bore/taper while you watch. NEVER assume it is correct...always verify. Some machine shop owners are skilled bullshitters. Some shops experiment with bore and bearing clearances without telling you. It is much easier to diagnose and assign blame BEFORE you turn the key. If you wait until you blow your engine or encounter an oil consumption problem, good luck proving a machine shop error. Before you drop your engine in...perform a leak down test. This will identify any valves not sealing or cylinder out of round issues. I would certainly expect less than 5%. Before you take them your engine, disassemble it and inspect for unusual wear problems. Uneven wear on the main bearings indicates either a bent crank or block that needs to be line honed (not uncommon). Do they have the right mandrel for the job? Remove the lifters and reinstall the cams. Do the cams bind or drag at all? If so, they engine was probably overheated at some point and warped they heads. If this is the case, they can deck the heads, but they MUST also line hone the cam journals. Does the shop have the right size mandrel for your cam journals? You can't correct one and not the other. Otherwise you can seize the cams in the heads. A set of warped heads will flatten somewhat when they are torqued down, which also straightens out the cam bore. If you deck the head nice and flat but don't touch the cam bore...boom!
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