... head(s) in an internal combustion engine.Its purpose is to seal the cylinders to ensure maximum compression and ... extreme cylinder pressuresWill not brinell(indent) aluminum cylinder heads Material is optional: metal, non-asbestos, graphite, asbestos, viton, silicone, ACM, NBR ... compromising on quality. 4. Not only the product quality is guaranteed, but also the customer service. Promise to deliver ...