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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.

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