SwRI: Caterpillar 1M-PC Test Method for engine oil categories API CF and API CF-2

The Caterpillar 1M-PC method simulates high-speed, supercharged, off-highway, heavy-duty diesel engine service and evaluates the performance of crankcase lubricants for:

• Piston deposits

• Ring sticking

• Piston scuffing

• Ring scuffing

• Liner scuffing

The Caterpillar 1M-PC method is part of API engine oil categories:

• API CF

• API CF-2

Caterpillar 1M-PC Test Equipment and Procedure

The Caterpillar 1M-PC test uses a Caterpillar 1Y73 single-cylinder indirect injection, diesel test engine with a two-valve arrangement. The test engine has a 5.125-inch bore and a 6.5-inch stroke, resulting in a displacement of 134.1 cubic inches. The compression ratio is 16.4:1, and this engine uses rectangular rings.

Test parameters are: 1,800 rpm, 42 bhp, 141 bmep, 5,850 Btu/min fuel input, 190°F coolant temperature, 205°F oil temperature, 255°F inlet air temperature at 53 inches Hg and 125 grains/lb, 23.5:1 air/fuel ratio for 120 hours.

Test parts meet Caterpillar's 3L quality specifications and include:

• Liner (1Y3995)

• Piston (1Y3589)

• Ring set (1Y3588) 

Caterpillar 1M-PC Test Results

Lubricant analysis includes new oil viscosity only.

	Results of Caterpillar 1M-PC analysis

Pass / Fail Criteria

• Ring sticking

• Piston scuffing

• Ring scuffing

• Liner scuffing

For API CF:

• Weighted total demerits (WTD) < 240

• Top groove fill < 70 percent

For API CF-2:

For CF-2, only the WTD rating applies using the following location factors. Limit for WTD is 100.
 

For more information about the Caterpillar 1M-PC 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.