I can remove OEM powder coat from all grease free engine items, especially cylinder heads and cylinders, using a very effective but expensive solvent designed specifically for powder coat removal. I've personally tried a number of solvents involving methylene chloride with no success. I've had powder removed from cylinder heads by North Carolina's largest coating removal service with good results but they still had to media blast some of the parts, especially at the base of the fins. The only media blasting that might be needed is the combustion chamber and ports, especially the exhaust port. No outer surface normally needs blasting. The process I use is extremely fast and leaves the base metal looking exactly like the original cast item before powder application. This stuff is fantastic.
