5-111.bk Page 9 Monday, July 10, 2006 2:26 PM ABOUT THE MACK ASET™ AC DIESEL ENGINE Although the drive to reduce emissions levels is primarily the result of government mandates, the ASET™AC engine is designed to be durable and easily maintained and to provide customers with good performance and fuel economy. This publication is intended to provide technicians with a working knowledge of the ASET™ AC diesel engine with cooled exhaust gas recirculation. MACK offers a similar engine to the AC which is more suited to the vocational applications called the AI/AMI. The AI/AMI engine is an internal exhaust gas recirculation design engine.
For service and overhaul procedures for the ASET™ AI/AMI engine, refer to the 5-110 ASET™ AI/AMI Engines Service Manual. ASET™ is an acronym meaning Application Specific Engine Technology. Mack Trucks, Inc. is looking beyond the borders of North America to increase its market and bring the quality, toughness and technology associated with the MACK name to a worldwide audience. The current environment of global regulations concerning exhaust emissions, noise and other factors has leveled the playing field on an international basis. This means that the improvements made to meet the North American environmental regulations are now applied worldwide.
The ASET™ AC engine design is based on the E-Tech™ left-side redesign (LSR) with its plate-type oil cooler and oil filter mounting arrangement. A redesigned Centri-Max ® ULTRA, and later ULTRA PLUS, centrifugal oil filter assembly and cover housing with an integral oil fill tube, is incorporated on all AC engines. Heater Core and Optional Fuel Heater Hose Connection Revisions Beginning second quarter of 2004, a cooling system revision was phased into production that affects the ASET™ AC engines to move the heater core and optional fuel heater coolant return hose connection point.
This change moves the heater core and optional fuel heater coolant return hoses from the thermostat housing bypass area to new locations on the lower radiator tube. This change is described in detail in the ENGINE DESIGN FEATURES section of this manual. The ASET™ AC utilizes a new EECU with greater capacity which is relocated to the front left-side of the inlet manifold. The increased capacity of the EECU requires the addition of a cooling plate to help dissipate heat. The AC design also provides for cooling of the exhaust gases being recirculated through the combustion chambers.
Descriptions of these design changes and the other features are provided in detail in the DESCRIPTION & OPERATION section. Additionally, the service effects of these changes on removal, installation, disassembly, assembly, setup and adjustment procedures, etc., are included in the MAINTENANCE and REPAIR INSTRUCTIONS sections. Development of the ASET™ AC engine has been driven by three basic requirements. It is designed to: Meet the year 2004 exhaust emission regulations. Meet customer demands for improved fuel economy, driveability and engine braking. Compete in a world market. Page 9 INTRODUCTION