Development of the Cylinder Block with Engine Oil Cooling Function

Abstract

In recent years, enhancing the engine thermal efficiency is strongly required. The high thermal efficiency raises the temperature of the combustion chamber and engine oil. So we developed new cylinder block structure which makes cool oil efficiently by engine cooling water near combustion chamber. We invented oil jacket structure with a function to cool oil in the cylinder block. The point of technology is the best balance of oil cooling performance and life of casting die by optimizing the shape of oil return passage near the water jacket. This invention could remove an oil cooler device and achieve lower cost. Toyota adopted this structure in Japan and a European market with 1.2-liter inline 4-cylinder engine (8NR-FTS).