Why dual valve springs are better than single valve springs? (explained)

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If the outer spring on the valve is broken in the way, what else is going to take you to the destination? Well, if the engine has dual valve springs, the remaining spring can do the job for the rest of the time.

Although the single valve spring is a lighter one compared to the dual one, the latter can last longer. Moreover, a dual spring reduces the resonance of the engine, which keeps the regular strength of the valve.

However, it often appears like a riddle to the users that whether the engine needs dual springs on the valve or a single spring is enough. And we're here to solve it.

Dual valve springs vs. Single

Comparison between dual and single valve springs

If you are worried thinking about choosing between single valve springs and dual ones, you're just in the right place. The simplest way to tell which is better is to consider the safety of the engine.

It leaves no further discussion regarding the safety as the Comp Cams Dual Valve Spring is way safer than Comp Cams Single Springs.

The one and only reason for dual springs being safer than single springs is because of having small, secondary springs inside the outer ones.

Now check out the following comparison chart before moving further in-depth discussion regarding the differences between these two springs.

Dual valve spring

Single valve spring

Two springs, one large and one small

Only one large spring

The secondary spring works as a damper

It works on its own

It ensures safety on the first spring failure

No safety if the main spring fails

Holding the valve from dropping

Can’t hold the valve from dropping

A reduced resonance on the spring

Not much reduction in the resonance of the spring

Higher spring rates 

Moderate spring rates

Long-lasting with similar RPM

Shorter lifespan compared to the dual one

It already works as a damper 

Can be used with a damper 

The number of springs

The distinguishing factor between dual valve springs and single valve springs is the number of springs each of these has.

Michigan Motorsports Dual Spring one has one major spring that works in the same way as the single spring. However, it has an additional spring as well for safety issues.

On the other hand, the single has only one spring. But if you want to increase the strength, it is allowed to add a damper with it.

Working method

The small valve spring included in the dual valve spring is known as the secondary option here. It appears as the rescue one when the main spring fails.

However, the work of both these springs depends highly on the spring rate. If an Empi Single Valve Spring can take the load of the rate, it’s good enough to go with it.

Meanwhile, the picture can be different if the rate seems higher as you may need a dual spring in that circumstance.

Safety measures

One of the main reasons why most users love to go for dual valve springs is because of safety reasons. The small spring inside the main spring of the dual one works as the main spring when the first one fails.

In a similar circumstance, a single spring couldn't save the valve from dropping in the cylinder. However, the secondary spring on the dual-on gets holds of the valve not letting it drop in the cylinder.

Resonance

Reducing the resonance of the springs can result in a reduction of the strength if it reaches the peak. And in this category, dual springs have two different springs with different resonances.

It doesn't allow both of these springs to reach the peak at the same time and lose their strength. As a result, it leaves fewer chances for the valve to bounce back from its seats.  

Lifespan

Comparing two springs keeping them in the same RPM, the oversized dual springs will last longer. Because of the having two different springs, the energy and work are divided into two sectors.

Comparison in similar conditions

If the spring rate is the same, and so is the RPM rate, it's enough going for a single spring. However, you need to ensure that also that the spring is compatible with the spring rate.

Moreover, if the spring can hold the weight of the valve up to a certain amount of RPM, going for a dual spring is a wise decision. The reason is that a dual spring can make the work half in two springs, which also ensures longevity.

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Dual valve springs

Dual valve springs

A dual valve spring is the combination of two springs, where the second one comes to the rescue of the valve if the first one fails. Unless there's a second spring, the valve will fall down in the cylinder.

The ultimate result of this will be the malfunction in the entire performance of the engine. It can also be said that the second spring acts as a safety measure for the valve to hold it up.

  • Dual valve springs rub against each other.
  • It works as a damper.
  • The second spring works as a safety measure.
  • Holds the valve from dropping in the engine.
  • Reduces the resonance of the spring.
  • It allows for higher spring rates.
  • Lasts longer even at a higher RPM.

Dual springs work in the same manner on the valve holding it up using the camshaft like a single spring. But what makes it better than the energy is divided into both springs, which enhances the lifespan.

When the valve has double springs, there is nothing you should worry about the safety. It will no more drop the valve in the engine as the second one will hold it up.

The less resonance on the spring, the fewer chances are there for the spring to lose its strength. And in this field, two-valve springs work in a better way to reduce the resonance. When it reaches the peak of resonance, the strength is reduced.

If you put both single valve springs and the dual valve springs with the same RPM rate, one with two springs will provide a longer lifespan even in the similar RPM that refers to revolutions per minute.

Single valve springs

Single valve springs

To avoid any failure in the engine or have relentless compression inside, springing the valves is a name of necessity. Between the two most common springs, a single valve spring only comes with one major spring.

A single spring supports the valve on its own, because of not have any additional smaller or secondary springs inside. However, the main downgrade of it is that if somehow the spring fails, the engine fails as well.

As there isn't any extra spring available to hold up the valve, it drops inside the cylinder and stops the engine mechanism.

  • A single spring that works on its own.
  • Failure of the spring means failure of the engine.
  • No secondary small spring is available.
  • It shuts off the valve.
  • Doesn’t allow the valve to bounce off the seat.
  • Can’t reduce the resonance much.
  • It can also work with a damper.

The selection between a dual spring valve and a single spring valve depends on the spring rate of the car's engine required. If the single spring can go on to match the required spring rate of the engine, it is fair enough going for it.

However, if safety is a key issue for the user, a single spring may not be the right one to choose as it comes alone. There isn't any extra or small spring in rubbing with the main spring here.

The engine can malfunction or drop the performance level if the main valve spring fails. The reason is that the spring creates a direct relation of the valve with the camshaft and the intake-exhaust system as well.

Are dual valve springs better than single?

Yes, dual valve springs are better in many ways compared to the singles. However, you need to make sure what actually the valve or vehicle’s engine requires from the spring.

Here are some of the major reasons why dual spring stays on top compared to single ones.

  • Dual springs work as a safety measure.
  • A longer lifespan.
  • Divides the work into two springs.
  • No worry about the engine or valve failure.
  • Reduces the resonance on the springs.
  • Provides higher spring rates.

Although a single spring can provide the required RPM rate to the valve, it still doesn't ensure the safety or relentless working of the engine.

And the deciding factor of which spring type is better than the other is the safety measure anyway. If somehow the main or large spring fails, the secondary spring works as the main function for this.

Due to the reduction of the resonance, it goes without saying that the dual spring can support the valve system for a longer time compared to the single one.

Moreover, a longer lifespan for the spring is another key factor that tells you the story about which one does the job better.

More about a valve spring

The valve spring is here to lift the weight of the valve when it is opened through the camshafts and closed through the valve spring.

Typically, the spring works with either one single spring or with two springs that contain one large, which is the main, and the smaller one which is the secondary one.

  • It holds the weight of the valve.
  • The camshaft opens the valve, and springs hold it.
  • Again, the springs close the valves.

Do valve springs make a difference

In a vehicle's engine, a valve spring does make a huge difference. It is an integral part of the engine as it holds the weight of the valve whether it's opened or closed.

If the spring fails, the valve just drops inside the cylinder. Ultimately, it affects the entire engine’s function as well. However, the double spring can get you relief from this problem.

The secondary spring comes into work when the first or the main spring fails. Therefore, it's fair enough to say that springs do make a difference in the engine.

Do I need dual valve springs?

If the spring rate with the camshaft is okay while the valve has only a single spring, you don't need to go for an extra one. However, some major reasons insist you go for a dual spring.

Ensures safety when the large spring fails.

  • Provides longevity.
  • Better working as the division of it between two springs.
  • Higher spring rates.
  • Reduction of the resonance on the spring.

Why do valves have a single spring?

Why anyone on the earth won't want to ensure safety while driving? And when the question is about safety, a dual valve spring does a better job for sure.

  • A single spring can work with a damper.
  • Keeps the valve in its place perfectly.
  • It works on its own.

Final verdict: Which springs should I go for

The decision depends on the engine and valve type of your vehicle. However, experts suggest going for the dual one as it can ensure the better safety of the engine.

On the other hand, if the single spring can produce the required spring rate that is good for the valve, it's a waste of money to go for a double one.

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DESIGN AND ANALYSIS OF ENGINE VALVE SPRING .pdf

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