Introduction

In - cylinder components are expected to experience higher operating temperatures and loads in future diesel engine designs, especially for the ring and liners. This will reguire the development and use of new materials, improved lubricants, and possibly new ring designs to provide an acceptable

Tribological System. Screening of these new systems in an engine is expensive and time consuming. To expedite screening. the Hohman-A9 high temperature wear simulator has been developed. This is a bench type fixture capable of testing potential lubricant, liner and ring combinations under simulated engine conditions of speed, load, temperature and lubrication.

In this paper operating characteristics and test results from the Hohman-A9 tester are described, and a comparison is made with results from the Cameron Plint tester, as well as diesel engine tests. Wear test results from the Hohman-A9 are presented for a plasma sprayed chromium oxide ring and liner (identifieid from engine testing as being a good combination), and a titanium carbide ring and chromium carbide liner (a poor wear combination). . The above combinations were tested at 427 C under loaded conditions with and without lubrication. Results are compared with a production chrome electroplated ring and gray iron liner combination.

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