Answer
Both Technicians (A and B) are correct since the aluminum cylinder head surfaces should be scraped clean only with nonmetallic tools to avoid gouging and it should also be chemically cleaned in accordance with the manufacturer's recommendations before the inspection.
Explanation
Cylinder heads are the cover ends of a cylinder which are in an internal combustion engine. These cylinders are made of aluminium. This is because they are mainly produced by gravity or the low pressure. This being that they allows a more rapid extraction of the combustion head compared to others. Note that even when the blocks of the engine are made of cast iron which contains a little carbon some amounts of silicon and manganese and traces of other impurities. The cylinder head is made of Aluminium
To avoid gauging the cylinder heads should be scrapped only with non metallic tools.This will prevent them from wearing out.The chemical cleaning is also done,this is by use of chemical cleaning agents.
