by Joanna Swanson
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The 3.9-liter Cummins turbo diesel engine is part of the B-series of engines created by Cummins. Its trade name is Cummins 4BT, a reference to its four-cylinder position as a B-series engine and the addition of a turbocharger. It is manufactured for use in commercial vans, marine and agricultural applications, among other applications.
Type and configuration
The 3.9-liter Cummins turbo diesel is an in-line four-cylinder engine with four cycles. It has turbocharged aspiration that is not intercooled. The bore is 4.02 inches and the stroke is 4.72 inches. The first cylinder to fire is number one, followed by three, four, and two.
The Cummins 4BT measures 37.7 inches high, 30.6 inches long, and 24.6 inches wide. It weighs between 745 and 782 pounds and has a gross vehicle weight rating of 16,000 pounds. It consumes 7.6 gallons of diesel per hour and the fuel pump operates between 0.5 psi and 10 psi.
Cooling and lubrication
The 3.9-liter Cummins engine cooling system can hold 8.8 quarts when it leaves room for the coolant to expand. The engine thermostat allows temperatures between 181 and 203 degrees Fahrenheit. Oil pressure ranges from 10 psi at idle to 30 to 65 psi in normal operation. The engine can carry up to 10.4 gallons of oil and can reach a maximum temperature of 250 degrees Fahrenheit.
Admission and Escape
The 4BT’s air intake system can generate 270 cubic feet per minute. The exhaust gas flow is 700 cubic feet per minute at 900 degrees Fahrenheit.
The 3.9-liter turbocharged engine can produce 150 horsepower at 2,800 rpm and 265 pound-feet of torque at 1,600 rpm. Its compression ratio is 17.5 to 1. The pistons operate at 2.205 feet per minute and the mean effective brake pressure is 177 psi.