Engine Timing Drives

Engine timing is of much importance to the motor vehicle engine. In all internal combustion engines, inlet and exhaust valves are to be open and closed at proper intervals. In diesel engines, fuel has to be injected with proper timing and in case of petrol engine ignition spark is to be introduced at correct timing. Only then the four strokes, i.e. suction, compression, power and exhaust occur and generate useful power.   

In early motor vehicle engines, timing wheels were employed to do above function and needed almost no attention other than lubrication. With the development of motor vehicle it has been needed to design engines with more power and efficiency, lower height, lesser weight, more silent operation and so on. In the attempt to achieve these properties engine timing wheel had to be replaced by metal timing chains and later even rubber timing belts. 

Timing chain is comparatively less liable to damage and needs almost no maintenance other than lubrication. In later motor vehicles we find toothed timing belts drives which are made of canvassed rubber material. Compared to metal timing chains rubber timing belt needs much attention. 

Under normal driving conditions a genuine timing belt can be used about 100,000 km or 4 years without damage. Timing belt replacement interval will be further reduced for vehicles operating continuously in low gears, carrying excessive loads and operating in hilly terrains.

Timing belt indicator bulb will show the correct time to replace the timing belt, if the system is set properly. The system can be adjusted to glow the timing belt indicator bulb at a predetermined distance of kilometers. Always the system has to be reset at every timing belt replacement so that the indicator bulb glow at the next replacement distance.

Timing belt drive replacement requires much attention to avoid engine timing being mismatched. It is essential to follow timing marks punched on timing gear wheels. The necessary instructions are given in the Service Manual.