Engine: Description and Operation

The 7.3L diesel engine is:
- a four-cycle turbocharged V-8 with overhead valves.
- 7.3 liter (444 cubic inch) displacement.
- separated into two banks, the right bank numbered 1, 3, 5, 7 and the left bank numbered 2, 4, 6, 8.
- rated at 215 horsepower at 3000 rpm.

The cylinder block has been designed to withstand the
loads of diesel operations by using:
- four-bolt main bearing caps.
- internal piston cooling oil jets.
- a forged steel crankshaft.
- heavy-duty forged steel connecting rods.

The piston and rings are:
- made of aluminum alloy.
- fitted with an upper keystone compression ring.
- fitted with a lower rectangular compression ring.
- fitted with oil control rings.

The piston pins are:
- a free-floating type permitting the piston pin to move/float freely in the piston pin bore.
- retained in the piston and rings by piston pin retainers.

The camshaft is:
- supported by five insert-type camshaft bearings.
- of the roller camshaft design.
- driven by the crankshaft through the use of the crankshaft gear and the camshaft gear.

The hydraulic valve tappets:
- minimize engine noise.
- maintain zero valve lash.
- incorporate camshaft follower guides.
- incorporate a roller follower design that reduces camshaft wear.

The cylinder heads are designed:
- to incorporate electronically controlled/hydraulically actuated fuel injectors
- to locate the fuel injectors in the center of the combustion chambers between the rocker arms.
- with integral high-pressure oil galleys.

The glow plug system is:
- designed to preheat the cylinders for faster cold weather starts.
- controlled by the powertrain control module (PCM).
- mounted directly into the cylinder heads .
- activated by the glow plug control module

The standard block heater is:
- designed to heat the engine coolant and oil for improved cold weather starts.
- located near the oil filter in the oil cooler.
- powered by a 120-volt external power source.
- replaceable but not repairable.

The fuel injection system used on the engine:
- is controlled by the powertrain control module.
- utilizes a two-phase fuel pump.
- circulates through a combination fuel filter, fuel heater and water separator assembly.
- uses eight electronically controlled/hydraulically actuated fuel injectors.
- maintains operating pressures between 21 - 275 kPa (3-40 psi).

The engine lubrication system:
- is divided into two systems: the low-pressure system lubricates the engine, the high-pressure system actuates the fuel injectors.
- maintains pressures between 0-414 kPa (0-60 psi) for the low-pressure system and 4137-20,685 kPa (600-3,000 psi) for the high-pressure system.
- is cooled by an engine oil cooler.
- utilizes an oil pressure sensor and an oil pressure regulator.
- actuates the exhaust back-pressure warm-up system integral to the turbocharger.