Which is Better, Timing Belt or Timing Chain?

What is the Difference Between a Timing Belt and Timing Chain?

The timing belt and timing chain are both very similar in what they do. They keep the camshafts and the crankshaft pulleys in sync, ensuring that the pistons and engine valves do not collide. The main differences between these two are materials used and the location in the engine. Timing chains are made from metal, usually steel, and are installed on the inside of the engine whereas timing belts are made from reinforced rubber bonded with a strong fibre material and are installed on the outside of the engine.

So Which is Better?

Due to constant development, it is very difficult to determine which option is better. In this article we will explore the advantages and disadvantages of both and see if we can come to a conclusion.

The Timing Belt

The timing belt is a more simple system than the timing chain. It does not require dedicated guide rails and does not need lubrication. From a manufacturers point of view the timing belt is cheaper to produce and results in a quieter engine, which can be more appealing to some drivers. It can be argued that the timing belt is also more efficient than the timing chain. This is because the belt rotates smoother, has more precise timing and less friction loss due to the teeth designed to mesh with those on the sprockets, giving it a tighter grip

The timing belt is much easier to replace as it is on the outside of the engine. Additionally, as the water pump is part of the same system this can be replaced at the same time for a reduced labour cost.

The timing belt would need replacing every 40,000 – 60,000 miles (80,000 – 100,000 with some modern belts). The belt will start to dry and crack with age and this is accelerated by any contamination of fluid, such as oil or coolant, extreme high and low temperatures and the quality of driving. Additionally, the timing belt can snap without warning and this can lead to catastrophic engine damage.

The Timing Chain

The main advantage of a chain over a belt is that they tend to be more durable and can handle more power, which is why more demanding vehicles will favour a chain over a belt. There is a common misconception that once a timing chain is fitted it will last the lifespan of the engine. As with most mechanical components the chain is still subject to wear over time. The quality of construction varies between manufacturers meaning that some timing chains will need to be replaced prematurely.

The timing chain is installed on the inside of the engine meaning that it can be more difficult to replace. As the water pump is not part of the same system there is extra work involved to replace it resulting in higher labour costs. Most manufacturers don’t specify a replacement interval.

As a chain starts to wear down and approaches the end of its life the chain links will start to elongate, a consequence of the sprocket teeth grinding against the link. As this happens the chain will start to rattle and this is a good indicator to the driver that the timing chain may need replacing. This is a huge advantage over the timing belt which will give no clear indication that it may be about to snap.

On the rare occasion that the timing chain breaks while driving this can result in some serious damage to the engine. If the chain were to snap while the vehicle is operational this will throw pieces of metal chain around the engine like shrapnel.

In Conclusion

Overall, there is no definitive answer as to which one is better as they both serve the same purpose with a few pros and cons each.

The timing belt is a lot tighter, cheaper and you may see slightly better results in terms of efficiency. On the other hand a timing chain can be used for more powerful applications, may last longer and can give a clear auditory indication that it is about to fail.

Timing chains seem like the better solution but due to the inconsistencies across manufacturers and the efficiency lost due to chain rattling it’s hard to place them as the truly superior option. Timing belts are cheap, easy to install and can be quite reliable with regular maintenance but with the risk of destroying the entire engine with no warning it is hard to place them at the top either.

GT Automotive Timing Chain & Timing Belt Kits

At the end of the day vehicle manufacturers will continue to use both and with persistent issues it’s important to have a good range of aftermarket timing belt and timing chain kits. We understand the importance of the system and this is why we stock a range of timing chain and timing belt kits to cover most relevant applications. Our kits are designed to match or exceed OE quality, with 4 decades of combined OE experience coming together to establish our high level of standard.

Find out more about our Timing Chain Kits

Find out more about our Timing Belt Components

Timing Belts VS Timing Chains