The guy who just completed re-boring my cylinders and cleaning up my valves suggested that I DO NOT want to do a powder coat now because of the parts needing to be heated to 400 degrees.

Is he right or wrong?

I could do the painting myself, but, I'm not real good at that kind if thing.

 

the valves have to come out to do the heads, not all powder needs to go to 400* but i see no issue in this at all. We have done it countless times with no problem at all. I mean hell a typical motor will run upward of 350* so i can not see how 35-45 min at 350-400* would create any issues at all. we just did a set of jugs last night that where freshly honed. no issues... we have also coated and then run a hone down jugs in the past to check for things like this and never seen any indication of any type of issues

 

I also agree that the 400 or so bake temp wont hurt any tolerance from machining. The typical engine runs around 400 degrees and can get hotter depending on moving at highway speeds or in stop and go traffic.