Subject: Technical - Product Info/Support
Message: I am considering using your coatings to decrease piston to wall clearance during an engine rebuild. I specialize in building Buick V6 turbo engines. My engine builds range from stock rebuilds up to 800 HP full race engines. We have been coating various parts of the power train since 2000, and our coatings have been used on pistons in applications ranging from chainsaws to 2000+ HP drag race engines.
Can you effectively coat used pistons to compensate for honing the cylinder a couple thousandths oversize? We can add up to .012" on the diameter with APC™. Our coatings are self-clearancing, so we recommend building the engine tight (a little too tight) and then allowing the pistons to find the geometry of each individual cylinder while under temp and under load during the break-in cycle.
This is a situation I run into often with customer\'s engines.
How durable is the coating? Theoretically, after break-in and as long as it is riding on the oil film it could last indefinitely. I could give numerous examples but here are just two: Mike Janis, a 2X Pro Modified World Champion, ran the same set of coated pistons for the entire 2014 season and reported that the pistons and the coating still look good at the end.
Roger Williams is a sprint car engine builder who normally replaces pistons after two seasons. He first tried our coatings in 2013 to see if he could get a 3rd season out of a specific set, and after a tremendously successful race year he contacted us in January to have the same pistons recoated for a 4th season. At PRI in Indianapolis last week he said that the pistons and bores still look good so he is going to have us strip and recoat them again for season #5.
As an aside, his driver stopped by our booth at PRI and said "with an 840 HP engine I didn't think I would be able to tell the difference, but since we've started using your coatings my engine runs smoother."
Do you have any issues with delamination? No
How much do you charge per piston? The cost for 6 pistons is $33 each for up to .006" on the diameter. For coating over .006" diametric thickness add $2 per .001". For 8 or more of the same part number the cost is $30 per piston, so you could save by having multiple sets coated at the same time.
Looking forward to your response. Looking forward to coating your parts! Other successful applications for our coatings include oil pumps, blower rotors, bearing shells and gears.
Thanks again for your interest.