1989-09-01

Testing an Anti-Friction Coating in a Small Engine 891761

This paper describes tests of friction-reducing coatings applied to single-cylinder, splash-lubricated, gasoline engines. The suppliers of the coatings anticipated a significant, (10-15%), decrease in fuel consumption as a result of covering most engine contact surfaces with a proprietary, FIFE-type plastic. However, a brief analysis indicates that possible benefits should be closer to 3% at high engine loads. To establish coating effectiveness, carefully controlled fuel economy testing of two engines was performed on a water-braise dynamometer at one engine speed and two output torque levels (approximately 70% and 95% of rated load). Test results showed increased fuel consumption on both coated engines compared with uncoated engines. Direct comparisons showed fuel consumption was 8% higher at full load and 10% higher at part load. This unexpected increase in fuel consumption was attributed to increased friction in the journal bearings of the engine. The coating interfered with the normal hydrodynamic lubrication,

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 43% off list price.
Login to see discount.
Special Offer: With TechSelect, you decide what SAE Technical Papers you need, when you need them, and how much you want to pay.
X