SwRI: Caterpillar 1-P Test Method for crankcase lubricants for category API CH-4

	Caterpillar 1-P test method apparatus at SwRI

The Caterpillar 1-P test method evaluates the performance of crankcase lubricants, with a steel top, aluminum skirt, two-piece piston, for:

• Piston deposits

• Ring sticking

• Piston scuffing

• Ring scuffing

• Liner scuffing

• Oil consumption

The Caterpillar 1-P test is part of lubricant category:

• API CH-4

High-speed turbocharged heavy-duty diesel engine service prior to 2002 is simulated.

Caterpillar 1-P Test Equipment and Procedure

	Pass
	Fail

The test fixture is a Caterpillar 1Y3700 single-cylinder, direct-injection diesel test engine with a four-valve arrangement having a 5.4-inch bore and a 6.5-inch stroke, resulting in a displacement of 148.8 cubic inches. Compression ratio is 16.25:1. Keystone top ring and second ring are used. The top ring is closer to the piston top than in the Caterpillar 1-K or Caterpillar 1-N. The engine features overhead cam and electronic injection control.

Test parameters are 1,800 rpm, 55 kW, 185 g/min fuel rate, 95 °C coolant, 130 °C oil, 60 °C intake air, 272 kPa intake air, 17.8 g/kg water vapor, 360-hour test length.

Caterpillar 1-P Test Results

The piston is rated by the Coordinating Research Council (CRC) demerit procedure. The following are evaluated at the end of the test:

• Piston

• Rings

• Liner

• Viscosity

• Total base number (TBN)

• Total acid number (TAN)

• Wear metals

• Fuel dilution

	Typical Reference Oil Result

The following are not allowed:

• Piston distress

• Ring distress

• Liner distress

• Stuck rings

Based on the time period in which a test is completed, an appropriate severity adjustment factor may be added to the test result. For a one-test run, the adjusted results are compared to the first test limits below.

For a two- or three-test program, the average of the adjusted test results is compared to the appropriate pass limits.

For more information about the Caterpillar 1-P test capabilities at Southwest Research Institute (SwRI) or how you can contract with SwRI, please contact Jim McCord at jmccord@swri.org or (210) 522-3439.