Abstract:
Reduction in power loses, fuel economy and check and control on emissions are the key
common drivers of automotive industry. Improvement of technologies and lubricant
formulations are considered to enhance engine performance and in order to do so an extensive
demand for comprehensive experimental work and precise measurement tools are required to
validate the effectiveness of these technologies. In roller follower valve train configuration, cam
and roller contact surfaces are largely responsible for power loses as friction between two
surfaces at cam roller interface based on different operating conditions and lubricant rheology.
In this research project, a real production gasoline engine with end pivoted roller follower
which is widely used in today’s passenger vehicles has been developed following new
development techniques using advanced sensor technology to measure the friction at a single
cam roller interface following actual engine environment. Following technique avoids any major
modifications to the roller and cam while observing their behavior at live operating engine. This
technique studies the friction at single cam lobe and follower by considering multiple variables
such as oil pressure, operating temperature, lubricant type and rotation speed. A good agreement
between theoretical data and experimental evidence also established. It is strongly believed that
the obtained realistic data will provide flexibility in validating the mathematical models on cam
trains and also beneficial for engine modifications and lubricant formulations in present efforts to
improve engine tribological efficiency.
