Camshafts

Camshafts information

Camshafts are generally made of forged steel and/or cast-iron material. The design of camshafts are unique to the engine it is made for, as the ‘lobes’ can be of varying sizes. Camshafts are typically mounted inside the cylinder head on an engine.

The camshaft makes use of lobes that push against the valves causing them to ‘open & close’. The job of the camshaft is a critical one and can have an impact on the engine’s performance.

There are two major types of camshafts – Flat Tappet and Roller Cams.

• Flat Tappet – have what appears to be a flat bottom where the cam lobe contacts the tappet.
• Roller Cams – these use a lifter with a roller on it.

Some engines utilize a camshaft on both the intake and exhaust side of the engines, these are known as Double Overhead Cam (DOHC) while other engines only make use with one camshaft (SOHC).

There are also engines that are considered “Pushrod Engines” – in these instances, the camshaft is inside the cylinder block itself rather than the head. The camshaft pushes on long rods the move through the block and into the cylinder head to move the rockers.

Here are a few indications that your camshaft might be bad:

• Vehicle does not drive like it used to.
• Drop in power or acceleration.
• Check engine light is on.

When possible, check the condition of the cam lobes for where or pitting as these could be indications that you will need to replace the camshaft soon.