Timing Belts Vs. Timing Chainsby Michael Ryan
Timing belts and timing chains control the timing of the values in an internal combustion engine. Without this synchronization, an engine would be difficult to start and impossible to keep running.
Both belts and chains connect the crankshaft to the camshaft, which is ultimately charged with timing the valves. The valves may be set up in a freewheeling setup, in which there is enough clearance between the valves and pistons to avoid contact if timing is out of sync, or an interference configuration, where engine damage will occur if the timing is interrupted.
Timing belts are less expensive than chains, but they are wear items that must be replaced. Timing chains are normally good for the life of a vehicle, but they are more expensive to design and install if service is needed.
During the 1970s and 1980s, many manufacturers started using timing belts, because of their lower cost and quieter operation. However, timing chains are once again popular and used on many North American and European models.
Although a timing belt and timing chain are not interchangeable, you should consider which setup a vehicle has before making a purchase. Timing belts require regular service and must be changed between 60,000 and 100,000 mile intervals. Regular oil changes are all that is needed to maintain a timing chain.
Some engines driven by both timing belts and chain have interference setups, where advancing or retarding the timing will effectively destroy the engine. If your manufacturer recommends scheduled inspections or timing belt service, do not avoid getting the work done, as it could cost thousands of dollars to fix the resulting damage.
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