Engine Timing

Engine Timing


In order for an internal combustion engine to actually run and produce power which is channelled to the wheels to drive a car, it needs to be in tune.

#see also  Internal combustion engines 101

Internal combustion engines have 2 main components, an engine block which houses a crankshaft and pistons and a cylinder head which houses valves and a camshaft/s, these two main components need to be in sync with each other and are kept so with various methods, in order for the internal combustion engine to run. I will cover the 3 main ones, namely:-

  • Timing belt system
  • Timing chain system
  • Timing gear system
A typical timing belt system
A timing chain system
A timing gear system

Timing Belt System

The timing belt system uses a toothed belt made of rubber compound meshing onto square shaped toothed gears to maintain the correct timing between the crank and camshafts,

#see also  timing belts.

It also incorporates a tensioner which allows for maintaining the correct tension on the timing belt automatically. Sometimes additional guide pulleys are also used to control excessive lash on the timing belts.

The cam shaft must be in a position to close both the inlet and exhaust valves. The crankshaft must be in position to place the piston at its topmost point in the corresponding cylinder.

This enables the engine to be in time and able to run. The setup must be maintained as long as the engine is running, so it is important that these components are kept in a good state of maintenance, failure would have expensive consequences.

Timing Chain System

In turn uses chains and spike toothed gears meshing into each other to maintain the all important timing of the engine, an oil pressurized timing chain tensioner system is used to keep constant tension on the chain and chain guides are used to reduce chain slap and guide the chain as it is rotated by the power of the crankshaft.

#More on chain drives

All these components are housed under a timing cover which seals the engine, preventing the oil from leaking out.

Timing Gear (constant mesh) system

This is one of the simplest methods of timing an engine, 2 toothed gears in constant mesh to keep the crankshaft and camshaft in time.

#More on gears

There are no tensioners or guides used.

In Closing

No matter what timing system is used they all need maintenance or repair at some stage, some are longer lasting than others due to its construction and design, it is always a good idea to know the state of these components.

So when you next visit your Auto Mechanic, enquire about the state of your engines’ timing system.

About Me

Gary De La Cruz

I have been 30+ years in the motor industry, still hands on, and have great passion for my chosen profession, I learn new things each day and believe that "if you enjoy your work, you never have to work a day in your life"I believe in honesty, integrity and helping where help is needed.

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