SwRI: Caterpillar 1-N Procedure for lubricants categories API CG-4 and API CI-4

The Caterpillar 1-N procedure simulates high-speed, turbocharged, heavy-duty diesel engine service prior to 1998 with low sulfur fuel.

This procedure is part of categories:

• API CG-4

• API CI-4

The Caterpillar 1-N procedure evaluates the performance of crankcase lubricants with lower sulfur fuel for:

• Piston deposits

• Ring sticking

• Piston scuffing

• Ring scuffing

• Liner scuffing

• Oil consumption

Caterpillar 1-N Procedure Equipment and Procedure

The fixture is a Caterpillar 1Y540 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 14.5:1. Keystone top ring and rectangular second ring are used.

Procedure parameters are: 2,100 rpm, 70 bhp, 1,800 bmep, 7,990 Btu/min fuel input, 200 °F coolant temperature, 225 °F, 260 °F inlet air temperature at 71 inches of mercury and 125 grains/lb, 29:1 air/fuel ratio for 252 hours.

Halterman reference fuel with a sulfur specification of 0.03-0.05 mass percent and an API gravity specification of 33-35° is used.

Caterpillar 1-N Procedure Results

Piston, rings, and liner are evaluated at the end of the procedure. The piston is rated by the Coordinating Research Council (CRC) demerit procedure. Lubricant analysis includes:

• Viscosity

• Total base number (TBN)

• Wear metals

• Fuel dilution

For CG-4, based on reference oil 1004, the following acceptance limits apply. Based on the time period in which a procedure is completed, an appropriate severity adjustment factor may be added to the result.

• For a first run, the adjusted results are compared to the first procedure limits below.

• For a two- or three-procedure program, the average of the adjusted results are compared to the appropriate pass limits.

For more information about the Caterpillar 1-N procedure 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.