Now there is a lot of controversy about which timing drive is better - a timing belt or a timing chain. VAZ used to be equipped with the latest type of drive. However, with the release of new models, the manufacturer switched to a belt. Now many companies are moving to use such a transfer. Even modern units with a V8 cylinder layout are equipped with a belt drive. But many motorists are not happy with this decision. Why is the timing chain a thing of the past? Let's look at its features, advantages and disadvantages.
The timing chain (including VAZ) serves to transfer forces from the crankshaft to the camshaft.
Thanks to it, the correct gas distribution is performed - the valves open and close on time. There are marks on the pulley. They allow you to correctly set the position of the crankshaft relative to the camshaft. Until the 90s, the chain was the main drive for the internal combustion engine. Few automakersthen I imagined that in the 2000s it would be massively abandoned.
Previously, this type of drive was really reliable and trouble-free. It has been used on gasoline and diesel engines. Often, manufacturers used not one, but several rows of links. By the way, on ZMZ 405 and 406 engines, two chains are used at once.
Tearing such a detail, unlike a belt, is extremely difficult. Now there are a huge number of cars from the 80s that “ran” more than 400 thousand kilometers without problems without changing the chain. Classic motors are indeed an order of magnitude more reliable than modern TSI and others.
Practice shows that this transmission stretches over time. Because of this, the timing chain marks do not match. For 10 years, it can stretch by 1-2 centimeters. Yes, it is much longer. But this is enough for her to jump one or more links.
On Ford cars, the timing chain takes care of about 200 thousand kilometers. Then there are characteristic sounds from under the hood. But this roar is completely curable - it is enough to purchase a repair kit with a new chain and tensioner. The problem will disappear for the next 200 thousand kilometers.
It is several times heavier than a belt. Modern manufacturers are making cars lighter, more environmentally friendly, and more compact. In order to meet the new emission standards and use less fuel, they are switching to a belt drive.
As for the chains themselves, their design has now been noticeably simplified. If earlier they used three links, now they use only one. The video has also been removed. Now installing leaf chains. Previously, metal sprockets were engaged with them. Now this function is performed by plastic spikes. But, as noted by the reviews of car owners, the resource of such a system has decreased significantly. In total, such a drive has become 5 kilograms lighter (taking into account the lightweight body). But is it worth it to sacrifice for weight?
Plenty of space under the hood
You may have noticed that the younger the car, the less space under the hood.
Manufacturers equip machines with many additional options and mechanisms. In view of this, it is necessary to rationally use the engine compartment. The belt drive does not take up as much space as the timing chain. Nissan and other foreign manufacturers switched to a belt precisely because of this. By the way, on vehicles with a transverse engine, a chain is not used at all.
What is the result?
As a result, all manufacturers switched to using a belt drive, which does not take up much space under the hood and does not affect the consumption and environmental friendliness of the car. But there is one "but". Such a mechanism tends to break. And it is extremely difficult to determine this, because it is closed in a plastic protective casing. The chain, when stretched, begins to emit a characteristic rumble that can be heard even with the best sound insulation.
Due to the ease of construction and the use of plastic elements, the chain resource has decreased to 100-150 thousand kilometers. There are also problems when replacing it. Due to the design features, it is difficult to get and replace. In service centers for the service of installing a new chain, they ask from 10 to 30 thousand rubles. The more cylinders in the engine, the higher the price tag. It becomes clear why 6 and 8-cylinder engines began to be equipped with a belt drive.
Which is better - timing chain or belt?
First of all, let's note the positive aspects of the chain drive:
- High resource (applies to older engines, where two and three rows of links are used).
- High resistance to external factors. The timing chain rotates in an enclosed space. She is not afraid of water, moisture, dust and temperature changes. For a belt drive, these factors can be critical.
- Adjustment accuracy. Unlike a belt, timing marks can be more accurately set on a chain. Due to this, the camshaft rotates with the required force. Fine tuning is more rational control of intake and exhaust valves. Accordingly, they do not burn through and do not coke, even as the links are stretched.
- Grease. The timing chain is constantly in oil. The belt runs dry. This significantly reduces its resource.
- Resistant to loads. The chain handles high RPMs very well. With a working tensioner, it will not jump a tooth forward, no matter what operating modes are.
It would seem that this is the most technologically advanced transmission in the timing. But worth itconsider shortcomings.
The first factor is the resource. It applies only to modern engines. For example, on Volkswagen cars with engine 1, 2, the chain takes care of no more than 50 thousand kilometers. This is less than a belt drive. The latter serves about 80 thousand. Plus, it's an expensive repair. You can replace the belt yourself.
But removing the chain in the absence of experience will be extremely difficult. The next disadvantage is noise. Such units are an order of magnitude noisier, even when the chain is not extended. The belt is made of rubber-fabric materials. It fits more gently on the pulley and runs silently. Now about the hydraulic tensioners that are used in the chain drive. These parts are very demanding on the quality and level of oil. If your engine is eating up grease, you should check the dipstick more often, otherwise the fluid will not enter the tensioner and the chain will jump on the tooth. The better the oil, the longer it will last.
Are any good manufacturers left?
Speaking of modern chain driven engines, it is worth noting that not all manufacturers have switched to “lightweight” options. Plastic chains are not installed on the engines of the popular Hyundai Solaris and its fellow Kia Rio. Even on the latest generations.
This uses a roller metal chain with double row links. Its resource is from 150 to 200 thousand kilometers. If you change the oil in time, the chain will last longer.
So we found outfeatures of both types of drive. It is quite difficult to answer the question “what is better - a timing chain or a belt”. You need to get away from the design. If it's a classic 2- or 3-strand chain with real, metal (rather than plastic) sprockets, this engine is definitely worth considering. When buying a car with a timing belt, remember that it can break and bend the valves in the engine (the latter does not apply to internal combustion engines with a SOHC layout). This is fraught with costly repairs.