Sunday, April 11, 2010

International DT Engines Overview

DT Engine Design & The Wet Sleeve

International DT Engines have a wet sleeve meaning the cylinder wall is a seperate machined part that presses into the engine block. The sleeve is in contact with engine coolant which is why it comes by it's description "Wet Sleeve"

International runs the wet sleeve design because it increases the durability and the cylinder wall thickness has a much better heat transfer which allows the cylinders to stay round when going through thermal expansion. Also, the cylinder sleeve is much harder than the cast block cylinder making the DT design much more wear resistant.

Rebuilding the DT Diesel Engine is very convenient since the block stays in the frame, hence the term "In-Frame". The sleeves being removeable saves the block from damage since the sleeves are replaced during the inframe process, saving time and extra costs.

With standard cast engine blocks the cylinder bores have to be machined. If there is major damage, in some cases the block might not be salvaged. Standard block cylinders become out of round during thermal expansion and wear much faster than the stronger DT steel cylinder sleeves.

DT Engine Fuel Injection 

DT engines used a Bosch pump-line-nozzle (PLN) mechanical direct fuel injection system  from 1984 until late 1995.  DTs used a Bosch MW style pump 1984 through 1992, while the  Bosch P style pump came into force between 1993-1995 where the New Generation Diesel engine design began, which is still the same basic block design.

Up to 1997 mechanical injection was used but in rare occasions. Emissions tightening started in 1994 and the injection systems were redesigned using electronically-controlled unit direct fuel injection.

HEUI (Hydraulically-actuated Electronically-controlled Unit Injection) injectors, co-developed by Navistar and Caterpillar were unleashed from 1994 to 2004. From 2004 the engines use Electro-Hydraulic Generation 2 Unit Injectors nicknamed "G2 injectors".


Medium/Heavy Duty Truck Engines, Fuel & Computerized Management Systems

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