Engine cylinder with textured surface.

Smooth Ride Ahead: How Texturing Cylinder Liners Can Revolutionize Engine Performance

Elliot Brynn in Tech & Innovation September 2025 • 4 min read.

"Discover how innovative surface texturing can adapt engine lubrication to different combustion modes, improving efficiency and reducing wear."

As the world grapples with dwindling fossil fuel resources and escalating air pollution, the automotive industry is under immense pressure to design high-efficiency, eco-friendly internal combustion engines. This push for sustainability has led to increasingly stringent vehicle emission regulations, demanding higher standards for emissions and fuel consumption control.

In recent years, the focus has shifted towards innovative in-cylinder combustion modes that promise to reduce soot and NOx emissions in diesel engines without sacrificing fuel efficiency. Modulated kinetic mode, premixed charge combustion ignition (PCCI), and homogeneous charge combustion ignition (HCCI) are at the forefront of this revolution. However, these novel modes introduce significant changes in combustion phases and peak gas pressures compared to conventional combustion (CC), challenging the lubrication systems of critical engine components.

The cylinder liner-piston ring (CL-PR) pair, a core component of any engine, is heavily influenced by these changes in external load. The shift in combustion mode can lead to unstable friction properties, particularly around the top dead center (TDC) of the compression stroke where lubrication is often poor. This is where the innovative technique of surface texturing cylinder liners comes into play, promising a smoother, more adaptable solution.

The Magic of Micro-Dimples: How Surface Texturing Enhances Lubrication

Surface texturing involves creating micro-dimples on the cylinder liner's surface to improve lubrication and reduce friction. These micro-dimples enhance hydrodynamic effects between the ring and liner, increasing oil film thickness and its bearing capacity. By strategically modifying the surface, engineers can optimize the tribological properties of the ring/liner pair, making it more adaptable to varying combustion modes.

A mixed lubrication model was built to investigate the tribological properties of a liner textured with micro-dimples. The simulation results indicate that surface texturing can improve the lubrication and friction properties of the ring/liner pair and adapt to different combustion modes in an engine.

Enhanced Hydrodynamic Effects: Micro-dimples increase the oil film thickness and bearing capacity.
Reduced Asperity Contact: Decreases direct contact between surfaces, minimizing wear.
Improved Tribological Properties: Optimizes friction and lubrication for better performance.

The study detailed how the numerical fluctuation ranges of key parameters like maximum asperity pressure, average friction force, and frictional loss were significantly reduced. Specifically, these parameters were narrowed by 21.6%, 27.8%, and 24.5%, respectively, across three different combustion modes around the top dead center of the compression stroke. This reduction signifies a more stable and predictable lubrication performance, crucial for engine longevity and efficiency.

The Road Ahead: Optimizing and Verifying Surface Texturing

While the simulation results are promising, the journey doesn't end here. The next crucial step involves optimizing the parameters of these micro-textures to maximize lubrication adaptability across different novel combustion modes. Future research will focus on conducting engine bench tests to validate these findings and fine-tune the surface texturing designs for optimal performance in real-world conditions.

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Everything You Need To Know

What is the primary goal of surface texturing on cylinder liners?

The primary goal of surface texturing on the cylinder liners is to improve lubrication and reduce friction within the cylinder liner-piston ring (CL-PR) pair. This is achieved by creating micro-dimples on the cylinder liner's surface, which enhances hydrodynamic effects, increases oil film thickness, and improves the bearing capacity. This ultimately leads to better engine performance and efficiency, particularly in the context of varying combustion modes.

How does surface texturing adapt to different combustion modes like PCCI and HCCI?

Surface texturing on the cylinder liners is designed to adapt to different combustion modes by optimizing the tribological properties of the ring/liner pair. Novel combustion modes like modulated kinetic mode, premixed charge combustion ignition (PCCI), and homogeneous charge combustion ignition (HCCI) introduce changes in combustion phases and peak gas pressures compared to conventional combustion (CC). The micro-dimples help the lubrication system to deal with the unstable friction properties, especially around the top dead center (TDC) of the compression stroke. Surface texturing provides a more stable and adaptable solution, crucial for the engine's longevity and efficiency across various combustion modes.

What are the key benefits of micro-dimples on cylinder liners?

The key benefits of micro-dimples on cylinder liners include enhanced hydrodynamic effects, reduced asperity contact, and improved tribological properties. Micro-dimples increase the oil film thickness and bearing capacity, which leads to less direct contact between surfaces and therefore minimizing wear. By optimizing these properties, the friction and lubrication are improved, resulting in better engine performance and a smoother, more efficient ride.

In what ways did the study demonstrate the effectiveness of surface texturing?

The study demonstrated the effectiveness of surface texturing through a mixed lubrication model. The simulation results indicated that surface texturing on the cylinder liner improved lubrication and friction properties and adapted to different combustion modes. The numerical fluctuation ranges of key parameters like maximum asperity pressure, average friction force, and frictional loss were significantly reduced. Specifically, these parameters were narrowed by 21.6%, 27.8%, and 24.5%, respectively, across three different combustion modes around the top dead center of the compression stroke. These reductions demonstrate more stable and predictable lubrication performance.

What future steps are planned to further optimize and validate surface texturing techniques?

The next crucial step involves optimizing the parameters of these micro-textures to maximize lubrication adaptability across different novel combustion modes. Future research will focus on conducting engine bench tests to validate these findings and fine-tune the surface texturing designs for optimal performance in real-world conditions. This includes the investigation of parameters like the size, shape, and density of the micro-dimples, to ensure optimal lubrication performance across a range of engine operating conditions and combustion modes. This validation process is essential to move from simulation to real-world application.