Which engine is better – with the timing chain or timing belt?
What is better in the car – timing belt or timing chain?
You like questions like “Which car is better?”, which, in principle, there is no right answer? Usually these issues cause the rapid wave of debate and even harsh polemics. Today we decided to talk about the timing system (timing) in internal combustion engines (ice). Everyone knows that in internal combustion engines to synchronize the operation of the engine use timing chain or belt.
But how do they differ from each other? Has long many motorists wondering what’s better? And I must admit that since then, how to replace timing chain came strap, disputes among motorists continues. Especially on modern engines that have a lot of complaints on service life. I must admit that is a great question. But to answer which is better – the chain or the belt, the fly will not work. We will try to make an unusual comparison of the two systems that each made his choice.
A time bomb under the hood of your car
In chapters 1-5 we will tell you that from a historical point of view, the variant with the timing belt is neither the best nor the worst, as well as the timing chain. Our personal opinion that the chain and timing belt are not a perfect system of valve timing in internal combustion engines. In General, this technology has long proven itself reliable and has stood the test of time. Nevertheless, she mercilessly outdated. In the 21st century, and trust me, automakers today are attracted to more modern technology. That is why more and more companies are beginning to think about electric cars and hydrogen cars.
In principle, finding out which is better – chain or timing belt is a thankless job. Those who love to argue on this matter, still not achieved the truth. All these artificial debate similar to the dispute between those who like foaming at the mouth to prove which car is the best.
Most interesting is that those who argue about what type of drive system timing is better, for some reason do not think that the entire system timing is a ticking time bomb. Especially in modern cars. Because of the timing system, the car’s engine is short-lived. Timing is the weak link in many cars.
The evolution of the system timing
Chapter 1: Gear gear
The main purpose of using chains or timing belts in internal combustion engines is the transport of energy (torque) from a crankshaft rotation to a valve device in the cylinder head, which are usually controlled by a camshaft (Cam).
This problem is not so difficult to solve. The obvious solution is the use of gears. It is through them that easy to transmit a torque in the lateral direction.
Here gear gear Volvo P1800S:
Yes, it’s gear that Volvo P1800S 1966, which drove almost 5 million miles. The motor in this machine without a single repair ran more than 3 million kilometers. Next, we conducted an expensive repair, and he would have cycled more than 1 million kilometers. And now about the sad.
What do you think, is it profitable to automakers to produce the cars which can serve the owner for a long period of time? The more the life of the car, the less sales of automakers. Can you imagine how today went cars if they were equipped to transmit torque from the crankshaft to the camshaft toothed gears? Imagine if you were CEO of a company that sold the product, who served 50 years, not 10.
As far as we can judge, the leaders of major car companies decided at one point in the history of automobile industry to design engines to reduce their service life. We don’t know, it was done on purpose or out of necessity. But the essence remains the same.
Starting to design the engine with a smaller resource companies have sought first and foremost to their advantage to operating in the world, faster cars were in the junkyard that would have increased new car sales. But how to do it without the complaints of car owners? Very simple. Need to come up with clever new technology!
Chapter 1.5: the Nylon toothed gear
The first solution to the problem of durability of engines, which we want to discuss is quite revealing – replacement metal gear gear on gear with nylon teeth, which are mounted directly on the metal.
This is gear from the engine of the Chrysler 383 1969. It is important to know that these gears are more expensive than regular metal gear-mechanism.
This is because the nylon is very expensive. As an alternative you can certainly use a cheaper plastic. But plastic gear is actually more expensive than steel. As for the production of plastic gears need 30 times more material than in the production of metal. The only way to ensure that the plastic gear was kept the same load, and steel.
What do you think the excuse invented for the automakers, which have recently become instead of steel gears use plastic? They explained the replacement of steel gears by the need to make engines quieter. However, this is a weak argument that can only believe Amateurs. More on that below.
Chapter 2: timing Chain
When some manufacturers began to use nylon gear, there is one problem: gear was too weak. In the end, the automakers began to receive a lot of criticism. The following technology of energy transmission synchronization engine steel timing chain. It’s a smarter way to reduce engine life so that consumers are not complaining.
From an engineering point of view, the principle of operation of the circuit timing in a timing mechanism based on the torque transmission on large distances, like on this bike:
The importance of this mechanism has a rear spring that helps keep the chain stretch when you switch speeds on the bike. After all, when the chain jumps to another star, its length of the line segment is changed. If it were not a special mechanism, when you shift the chain on the bike was loose or even came off.
This problem in the car does not exist. But there is in the car his troubles. For example, the timing chain will wear out eventually (and if you compare with toothed gears, chain wear is happening very, very quickly). This leads to an increase in the effective chain length over time. Therefore, the makers have equipped the timing chain tensioner to correct her sagging. Well, here you have another proof that the manufacturers intentionally decreased the lifetime of the engine components by using timing chain.
In principle, to use a circuit was not necessary. The more that torque from the crankshaft to the camshaft to be transmitted to small distances. But no. Automakers decided to equip all the engines with a timing chain that wears out very quickly compared to gears.
It certainly solved the problem of durability of engines of the 60-ies.
Here are two solutions chain drive timing system:
The picture on the left you can see the engine is equipped with long valve tappets (scheme OHV). This motor uses a small chain. On the right you see the engine, with OHC or DOHC, which uses a long chain. The design on the left is designed for a longer service life. Also, the motor design on the left is cheaper and easier. More the long chains used in engines are OHC design, with time and more worn out and stretched. The worst is when the engines with two chains one chain wears out faster than the other. In this case, the tensioner is more worn the chain will degrade the ideal timing of the motor.
But many automakers use a variety of technologies to prevent such an asymmetry in the synchronization engine as a result of chain wear or stretching.
In some engines there is a system variable valve timing, such as VTECH or VANOS. In such engines, the chain tensioner is connected to the device timing synchronization. On such motors in the event of sagging of the chain from wear and tear, it is automatically slightly moving a few links.
But in all these examples, when using the chain, we do not see systems, to prevent rapid wear of the chains. Instead of trying to figure out how to prolong the service life of the timing chains, the brands are all made in order to strongly stretched chain experienced the maximum mechanical friction. This means that, over time, is violated not only stretch the chain causing it to wear, but also wear out the chain tensioners.
Chapter 3: timing Belts
The durability of the engines can be solved by using the straps? If you are an engineer in a car company that wants you to figure out how to shorten the life of engines, then you certainly do not dwell on the timing chains. You will definitely come up with something else, happily telling his leaders that instead of the timing chains need to use timing belts.
And that is exactly what happened in the history of automobile industry. Timing belts have become the next step in the conspiracy against car owners who dream all my life to own one car. Timing belts have replaced chains in many cars.
Belts timing came on the scene back in 1962. But early belts were not as popular as in those years there was no technology capable of producing strong belts. And it was in rubber, which made the first belts. It is known that rubber at high temperatures is rapidly aging.
In the end, the first belt was short and rushed, which often lead to significant engine damage. Then, belts have become more reliable, and the brands began to abandon the chains, also stating that it is necessary to reduce the noise of the engines. But despite the technology of production of timing belts, they are still on the service life of inferior timing chains. Automakers have done so, car owners often came in for maintenance to replace the timing belt (which costs a lot of money).
In modern cars the timing belts are more long term in comparison with old cars. In some cars the timing belt should be changed every 100-150 thousand km, while more recently, some car manufacturers recommend to change the belt every 30-45 thousand.
But this does not mean that now the timing belts have the advantage over the circuit. It also does not mean that you should run to buy only cars with the timing chain. It is not so simple.
Chapter 4: Chains with plastic guides
The following solution to the problem of durability of the vehicles was the transition of manufacturers with the use of conventional circuits on the circuit, which use a curved plastic rails. This plastic is falling apart with time. But don’t be surprised. It was originally invented so that the plastic guide broke down after a certain mileage.
Plus, these modern motors use indirect long chain. That is the principle, as this 10-speed bike:
From an engineering point of view in order to effectively transmit a torque along the long chain of necessary additional gear. But in the above example in the video chain in modern engines is curved and constantly interacts not with the gear, as expected, but with a piece of PLASTIC!
What is more expensive – timing chain or timing belt?
So, we looked at how brands have moved from the gear on the timing chain, then the timing belts and now has again decided to use a chain. Now to understand that it is cheaper to maintain a car with a timing belt or chain? Of course, it all depends on the make and model of the vehicle. But overall something that is what comes out, as it may seem at first strange.
The timing belt is, of course, cheaper chain. But as soon as the timing belt you get the pulleys and everything else, the cost of replacing the timing belt and drive rollers will be approximately comparable to the cost of replacing the timing chain.
If we talk about old used cars, then of course, it is preferable to buy a car with a classic chain that is ancient technology, time-tested. If to speak about new modern cars, it is better to buy cars with timing belt, since the new chain technology timing, is gaining popularity again, is flawed and less reliable than the old classic chain timing system.
But with cars that use timing belts need to be careful because belts tend suddenly to break from wear or factory defects. In this case, many engines waiting for the crash, because the motor valves will meet pistons.
Chapter 5: variety is the spice of life
We only touched the question of what happens to the evolution of cars. All really complicated. Here you can read why modern engines are much worse than the old one.
The car manufacturers have a lot of questions. For example, why is the Mercedes E-class released for the taxis of Germany, can easily travel 500 thousand km, while the normal version can not always without repair to reach such a mileage? Or why modern trucks, as well as old, can still easily wound without repair for more than 1-2 million kilometers, despite the fact that the engines of the trucks higher the compression ratio and torque?
Or, for example, why modern oxygen sensors fail much faster than in older machines? Or why the manufacturers of steel in the construction of many components to use metal parts instead of plastic that eventually led to a significant reduction of the service life of the vehicles? And these issues are thousands.
Usually manufacturers all the questions are answered simply: replace metal parts with plastic is necessary to reduce the weight of cars. But wait a minute, what in the world is aluminium? But no, the car manufacturers continue to degrade the car, facilitating all mostly plastic.
Really need to write a textbook to list all the details that have deteriorated in modern machines.
Summary: So which is better?
As we have already noted, to determine exactly what is better – a belt or a chain, is not possible. Those who are arguing about it, wasting my time. Artificial is a pointless argument. Each type of timing has its pros and cons. It all depends on the type and design of the engine, as well as the cost of the replacement belt/timing chain in a specific car. For example, some cars have a belt/chain change is pretty easy and costs nezaoblachno amount, whereas in other machines to replace the chain/belt need to disassemble almost half a car, which eventually comes in a round sum. In conclusion, here are some key advantages of timing belts and timing chains.
The advantages of timing belts
- The best timing accuracy helps improve performance and reduce emissions
- Low noise
- Lower harmonics of the crankshaft (intermittent speed) that influence the dynamics and phase distribution
- Reduced friction
- Reducing lubrication requirements (oil is not required for belt)
- Ease of adjustment (for racing)
The advantages of the timing chains
- The chain has more resources
- When replacing the timing chain requires replacement of fewer components
- Less risk of breakage