A timing cover is a component typically found in internal combustion engines and is designed to protect components such as the timing gears and chain or belt. In applications that use a timing chain, the timing cover usually seals the front end of the block, while engines with timing belts typically have timing covers that are less integral. Timing covers can be made from either metal or plastic. Engines with timing chains usually have a metal cover, while those with a timing belt may utilize covers made from a variety of different materials.