Solid vs hydraulic lifters are often on the balance sheet for comparison, so which is the better choice?
Both will have advantages and disadvantages, affecting your vehicle’s performance. Depending on each car model or brand, the automobile will be equipped with one of these two types.
If you are confused, then we are here to help! Keep reading to learn more about them in the next sections!
What You Should Know About Solid And Hydraulic Lifters
A lifter cylinder separates a car’s cylinder valves and engine camshaft. The valve will be opened momentarily since the camshaft will actuate when it passes through the lifter’s top body.
Also, each comes with a different lifter because the exhaust and intake valves have to open at distinct times. Lifters can be made in multiple ways.
Solid Lifters
What do solid lifters look like?
A solid metal cylinder, as the name suggests, is what is meant by a lifter. The cylinder heads are either pressed down or allowed to rise while the solid lifter cam rotates.
This greatly lowers noise and boosts efficiency, especially at higher RPMs.
They have a few significant advantages over hydraulic pressure ones, even though they may be noisier. They are excellent for economy cars because they are inexpensive and low-maintenance.
Since they function dependably at higher RPMs than normal, performance cars can also benefit from them.
Hydraulic Lifters
It was first created in the 1930s to quiet down outdated mechanical lifters. But they didn’t reach the mainstream market until the 1950s due to their greater price.
The cylindrical body of this one has an internal piston.
The valve lash, or the distance between the valve tippet and the rocker arm, is something the lifter float piston design seeks to minimize, out of the lifter bore.
Larger levels of the lash can generate a rattling and engine knocking sound but are more forgiving. The ride will be quieter and smoother the less lash there is.
Solid vs Hydraulic Lifters Comparison
How to tell the difference between solid and hydraulic lifters?
We can base on these criteria to carry out: performance, configuration, mechanism, design, and noise and wear. And solid models seem to outweigh in performance.
Performance
As you rev up the engine, solid lifters improve adjustable valve train control and minimize the deflection.
This also enables the valve train to generate more RPM. Solid lifters offer better engine performance at 7,000 RPM or higher.
Configuration
Solid lifters vs. hydraulic comparison also shows differences in configuration. The cam lobe and valve stem must typically have some mechanical space when installing solid lifters.
Preload or the distance between the plunger seat and retaining snap ring while the engine valve is closed. This is necessary for hydraulic roller lifters, though.
An engine camshaft controls the timing, lift, and duration that valves are open and closed.
The intermediate parts of an overhead hydraulic and solid lifter cam design are unusual because they use a follower instead of a pushrod and potentially a tappet.
Design
The hydraulic design has a free-moving internal lifter piston assembly inside the outer body.
This piston assembly moves to account for temperature increase and component extra wear to maintain a net zero lash in its valve train.
Throughout the engine’s life, they often never need to be modified again once they are set to the recommended preload.
There is zero effective loss and no internal moving parts in the design of the solid ones. This intimate lifter needs some initial valve lash to allow for thermal development in the valve train.
Throughout an engine’s lifespan, this valve lash will fluctuate. And it must typically be readjusted to maintain the fair value specified by the engine manufacturer.
Mechanism
With a different design, the mechanism of hydraulic vs. solid lifters is not the same.
Self-adjusting mechanisms are a feature of the former. Via one aperture, engine oil pressure enters the lifter, and through another, it enters the hollow body of the plunger.
The hydraulic lifter, which helps to zero out the clearance in normal operation, can either bleed down or pump up under the strains of high RPM.
By allowing fluid to flow past the plunger piston of the lifter during the lifting cycle, all of them can absorb a tiny amount of the cam’s lift profile when operating.
Solid lifters need extra clearance – so-called valve lash – to function effectively since they lack an internal mechanism to handle clearance.
The lifter needs to upload the valve train and let it close as the cam approaches the base circle.
Noise And Wear
The noise is generated when the clearances are stretched, and the engine is cold. Besides, the excessive wear as the parts move around are problems that come with a lash in a mechanical valve train.
Additionally, the rocker arm ratio and the multiplicative effect of the lash setting. This results in an effective old one lower than the height of the cam lobe.
Between hydraulic lifters vs. solid lifters, the latter will make more noise and wear out faster.
When To Use Solid Lifters vs. Hydraulic Lifters?
The pumping design is typically regarded as the downside of hydraulic lifters. As the cam pushes up, this sort of lifter slightly compresses, but the pushrod is kept in place by the rocker arms resistance.
Because of the small buffer created, they open the valves more slowly than solid roller cams.
The additional protection the valvetrain provides on a street-driven car justifies this cost. However, this reaction loss might harm actual performance on high-revving racing vehicles.
Hydraulic flat tappet lifters are taller, heavier, and more likely to pump up than solid ones. However, many engines with them can now readily manage 7,000 RPM or more.
It is because of advancements in its design, etc.
If you are into higher RPMs (say 8,000 or more), solid lifters will do a better job in safety.
How To Identify Solid Lifter vs. Hydraulic Lifter?
- To reach the valve train assembly, use a socket wrench to remove one of the valve covers.
- The valve train assembly will be visible once the valve cover has been removed.
- Find the position of the valve lash measurement.
- For rear-wheel drive engines, people measure the valve lash at the rocker arm’s closest end when standing on the side of the car. This is a transverse front-wheel drive engine, which we measure at the front of the vehicle.
- Each valve stem is surrounded by a valve spring pressure at the end of the roller rocker arm.
- Check for any space between the top of the valve stem and the rocker arm.
- There is a space between the top of the valve stem and the adjustable rocker arm on a solid lifter assembly.
- Identify a gap by inserting a feeler gauge.
- The gap’s size is irrelevant because a gap’s presence or absence can distinguish both of them: solid lifters come with a gap, while hydraulic ones don’t.
Bottom Lines
Obviously, solid vs hydraulic lifters have their pros and cons, depending on your requirements.
Most vehicles already have one, but you can also consider upgrading.
This means you need to pay a relatively large amount of money to improve your car performance.