Timing Belts V Belts & kits

What is a timing belt & how is it used

Timing belts & belt kits are a key item in keeping your engine running. It is recommended that the belt along with tensioners, pulleys and water pump (if belt driven) are replaced at the same time.

In an internal combustion engine a timing belt connects the crankshaft to the camshaft(s), which in turn control the opening and closing of the engine’s valves. A four-stroke engine requires that the valves open and close once every other revolution of the crankshaft. The timing belt does this. It has teeth to turn the camshaft(s) synchronized with the crankshaft, and is specifically designed for a particular engine. In some engine designs the timing belt may also be used to drive other engine components such as the water pump and oil pump.

What are timing belts made from

A timing belt is typically rubber with high-tensile fibres (e.g. fiberglass or Kevlar) running the length of the belt as tension members. The belt itself is manufactured from materials such as moulded polyurethane, neoprene or welded urethane. Various standard, non-standard or metric pitches are used for the teeth. The distance between the centres of two adjacent teeth on the timing belt is known as the pitch.

Heat and contact with engine oil degrade the belt material, which reduces the life expectancy of the belt. Modern high performance belts are made of temperature resistant materials such as “highly saturated nitrile” (HSN). Reinforcing cord life is also greatly affected by water and antifreeze. This means that special precautions must be taken for off-road applications to allow water to drain away or be sealed from contact with the belt.

Modern belts utilise curved teeth that are quieter and last longer, as opposed to older belts which have trapezoid shaped teeth leading to high rates of tooth wear.

MAR Motorsport stock a large range of timing belts & belt kits