Here’s a good video showing the basics of how a timing chain works: While several timing chains complicate the system, the basic functionality remains unchanged. And one or more timing chain tensioners may be employed to keep the chain taut and to account for eventual chain stretch.ĭepending on your engine configuration, it may have just one timing chain or several. Idler sprockets may be present to change the chain path of travel. Additional timing chain design features may include chain guides to constrain chain motion and reduce noise. See Also: Variable Valve Timing (VVT) Engine AdvantagesĮngine designers often use the timing chain to operate other engine components like the fuel pump, distributor, balance shaft(s), and/or the oil pump. It is the timing chain that makes this valve and piston coordination possible. This synchronized event is called ‘correct valve timing’. When the engine runs, the motion of each valve is precisely synchronized to the arrival and departure of each moving piston. A sprocket on that shaft drives the timing chain which in turn rotates the camshaft to operate the valves. These valves must open and close in precise coordination with the motion of the pistons. The timing chain operates the engine’s intake and exhaust valves. (complex timing chain) Credit How a Timing Chain Works Timing chains should not be confused with the timing belt which serves the same function but is uniquely different in design as well as failure modes. This housing is sealed and the chain(s) are lubricated and wear particles flushed away by the engine oil system.

Timing chains are enclosed in a housing located typically on the front of the engine. Roller chains operate in concert with high precision alloy steel sprockets. Larger, more powerful engines demand a double row design. Their design enables them to pass around smaller diameter sprockets thus demanding less space than the link chain design.įor light duty automobile engines, the roller chain may be of a single row configuration (like the bicycle chain). Roller chains are much like bicycle chains in appearance but are larger, far stronger and more durable. For this reason, this design is sometimes referred to as a ‘silent chain’. The link shape is intended to smoothly engage each sprocket. Each link’s shape conforms to the driving surfaces of both the crankshaft driving sprocket and camshaft driven sprocket. Link chains consist of many precision links fabricated of flat hardened alloy steel held together by pressed pins. These designs have their origins back into the late 19th century. Two types of timing chains are in service today, the link chain and the roller chain. See Also: DOHC vs SOHC Engine Types of Timing Chains In this regard, see the discussion regarding interference vs. Worse, this can also result in severe damage to the internal components of the engine. Click Here to chat online with a verified mechanic who will answer your questions.

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