What is the maximum hydrodynamic lubrication pressure that can be achieved between the crankshaft journal and bearing?

The maximum hydrodynamic lubrication pressure that can be achieved between a crankshaft journal and its bearing is generally recognized to be around 1000 PSI in most engine applications. This pressure facilitates the formation of a hydrodynamic film, which is essential for reducing friction and wear by keeping the moving surfaces separated by a thin layer of oil.

When the engine operates, particularly under high load or RPM conditions, hydrodynamic pressure builds up as the crankshaft journal rotates within the bearing. The design of the bearing and the viscosity of the oil contribute to this pressure. At approximately 1000 PSI, the lubrication system effectively prevents metal-to-metal contact, ensuring that the engine components operate efficiently and have a reduced risk of failure due to wear or overheating.

While greater pressures may be theoretically possible in some specialized applications, the typical limit of about 1000 PSI is considered optimal for maintaining efficient lubrication while also ensuring that the engine operates efficiently and safely.