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EM7-300 Mack Semi Engine Specifications

by Shea Laverty

Mack Trucks was founded in 1900, and has since become a well-recognized name in the world of truck manufacturing. Specializing in heavy-duty trucks and engines, Mack Trucks have produced vehicles to suit many industrial and transportation roles. The Mack EM7-300 engine was installed in Mack's RB and RD model lines until both the RB and RD were discontinued in 2004 and 2005, respectively.

Engine Type & Performance

The Mack EM7-300 is an 11.96-liter inline six-cylinder engine. This diesel-powered engine produces 300 horsepower at 1,750 rpm, and has a peak horsepower of 310 horsepower at 1,500 rpm. It generates 1,425 foot-pounds of torque at 1,020 rpm.

Oil System

The Mack EM7-300 features a full-flow ESI lube oil system with a Centri-Max centrifugal oil filter. It was designed to only require servicing every 16,000 miles.

Air Intake System

The Mack EM7-300's air-intake system features a 13-inch dry type single element air cleaner with an external cowl. It also features a gradual lock-up type air-restriction monitor.

Cooling System

The Mack EM7-300 uses a shutterless liquid cooling system. This system features a 1,050-square-inch radiator, and antifreeze effective up to -10 degrees Fahrenheit. This system also employs a viscous fan drive with an automatic tensioner-equipped polyvinyl fan belt.

Starting System

The Mack EM7-300 is equipped with a 12-volt electric starter. This starter is powered by two 12-volt batteries, each with a 925 CCA rating, for a combined CCA of 1,850. The alternator in the EM7-300 is a 12-volt, 100-ampere Delco 22 SI alternator.

Other Features

The Mack EM7-300 features a V-MAC III vehicle electronics system, and an aluminum flywheel housing. The hoses and tubing on the engine are made of silicone, and the heat-shielded exhaust system is vertically mounted. The air compressor can move 14.0 cubic feet of air per minute.

About the Author

This article was written by the It Still Runs team, copy edited and fact checked through a multi-point auditing system, in efforts to ensure our readers only receive the best information. To submit your questions or ideas, or to simply learn more about It Still Runs, contact us.

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