Abstract
Keywords
Friction Coefficient, SAE No.2, Low Velocity Friction Apparatus, Gear Pitting
Abstract
A four-stroke cycle (herinafter referred to as a "4-stroke") engine oil for motorcycle needs to lubricate not only the engine but also the clutch and the transmission. Higher frictional properties for motorcycle oils are required in contrast the lower frictional requirements of passenger car engine oils. Differences in frictional properties between motorcycle and passenger car engine oils were clearly found in our investigation with the SAE No.2 and the Low Velocity Friction Apparatus (LVFA) tests Modern passenger car engine oils having lower frictional properties may reduce clutch capacity in motorcycle engines. As such, it is important to develop 4-stroke engine oils for motorcycles which have high frictional properties and which also satisfy other critical engine performance requirements. Since many additives are being used in motorcycle engine oils, a study of the additive effects on frictional properties was conducted. Based on our study, a new additive package was developed which resulted in high frictional properties and good overall engine performance.