Modern Hydraulic Lifters: Advanced Lubrication More Important than Ever

Engine technology constantly evolves as engineers work to deliver more power, efficiency and emissions control. This relentless innovation improves vehicle performance, but places new challenges on engine components that operate under increasingly demanding conditions.

Hydraulic lifters are a prime example. They play a crucial role in ensuring optimal engine performance and efficiency. And, as they become more sophisticated, the task of motor oil to safeguard them against wear and failure becomes more challenging.

Hydraulic Lifters

The two primary types of valve lifters are mechanical (or solid) and hydraulic. Mechanical lifters are solid metal components that transfer the camshaft’s motion to the pushrods. They require a small clearance, or lash, to account for the thermal expansion of engine components. This lash must be periodically adjusted to maintain engine performance and prevent excessive wear.

Hydraulic lifters, also known as hydraulic tappets, are designed to maintain zero valve clearance regardless of engine temperature. They ensure the timing of valve openings and closings is precise to optimize engine performance, fuel efficiency and emissions. Their design allows them to adapt to the thermal expansion of engine components to maintain consistent valve timing. This not only contributes to smoother engine operation, but extends the life of the engine by minimizing wear on valvetrain components.

Each hydraulic valve contains an internal piston that operates under the pressure of the engine’s oil-circulation system and a one-way check valve that traps oil inside, allowing them to act as a solid lifter during valve operation. As oil enters the lifter, it pushes the piston upward, automatically compensating for any changes in engine dimension due to thermal expansion. The lifter’s self-adjusting mechanism negates the need for periodic manual adjustments, a task that was once necessary with traditional mechanical lifters.

Mechanical lifters can handle higher rpm and provide more precise control over valve timing, making them the choice for performance and racing applications. On the other hand, nearly 100% of modern production vehicles are equipped with hydraulic lifters due to their quieter operation and lower maintenance demands.

Hydraulic lifters have seen significant improvements to meet the demands of modern engines that are increasingly lighter, more compact and more powerful. Manufacturers make them with materials that offer greater wear resistance and durability, allowing lifters to operate effectively even under the high-stress, high-heat conditions found close to the combustion chamber. Lifters have also been designed to be compatible with lower-viscosity oils.

Common Issues

Hydraulic lifters face challenges. One common issue is lifter collapse, where the lifter fails to maintain proper pressure, leading to increased valve clearance and noisy operation. This can be caused by a variety of factors, including motor-oil contamination, air infiltration into the lifter or insufficient oil pressure. Over time, such conditions can lead to significant wear and eventual lifter failure.

Lifter noise can indicate problems such as improper lubrication or wear. If left unaddressed, these issues can escalate, leading to catastrophic failure. Regular maintenance and the use of high-quality motor oil are crucial to prevent these problems and maximize the longevity of hydraulic lifters.

Motor Oil’s Role

Motor oil plays a critical role in the protection and operation of hydraulic lifters. These components require constant lubrication to protect them from wear. The buildup of sludge and deposits can impede lifter function and lead to premature failure.

Motor oil with excellent thermal stability is important for protecting engine components from extreme heat, and that’s especially true with hydraulic lifters, which are exposed to the high temperatures generated by the combustion process.

AMSOIL Protection

AMSOIL motor oils provide exceptional protection for engine components, including hydraulic lifters. For example, AMSOIL Signature Series 100% Synthetic Motor Oil provides 75% more engine protection against horsepower loss and wear.1 It is fortified with a heavy treatment of detergent additives, delivering 28% more acid-neutralizing power than Mobil 1* and helping engines stay cleaner, longer.2 Robust anti-wear additives form a strong fluid film that separates metal surfaces, significantly reducing wear in metal-to-metal contact regions. Keeping components clean helps lifters last longer and maintain optimum performance.

Keep Lifters Lifting

Hydraulic lifters play a critical role in the operation and efficiency of modern engines. As hydraulic lifters become more advanced to support engines that are increasingly more compact, powerful and efficient, the importance of maintaining them with high-quality motor oil is more important than ever. Hydraulic lifters operate in extreme heat and require premium protection to perform optimally for the life of the vehicle. AMSOIL motor oils deliver premium protection and performance, ensuring that your engine, including its hydraulic lifters, remains in peak operating condition for many miles to come.