• Ford used the heavy-duty 7.3-liter engine in its F-250 and F-350 pickup trucks.pickup truck image by Tonda from Fotolia.com
  
  The 7.3-liter IDI diesel engine was used by Ford from 1988 until 1994 in its F-250 and F-350 pickup trucks. The 7.3 replaced the 6.9-liter, which Ford had used since 1983. The 7.3-liter IDI was manufactured by International.
  
  

Specifications

• The 7.3 L IDI uses a V8 cylinder design in the engine. The total piston displacement is 444 cubic inches, or 7.3 liters. The bore by stroke is 4.11 inches by 4.18 inches, while the compression ratio is 21.5-1. The maximum horsepower is 185 at 3,000 rpm, and peak torque is 360 pound-feet at 1,400 rpm.
  
  

Design

• The engine block and head are made of cast iron. The 7.3 IDI was not turbocharged until 1993. IDI stands for "indirect injection" and refers to the fuel beginning the combustion process in a pre-chamber before it enters the main combustion chamber. This method can reduce wear on an engine but can also decrease engine performance and efficiency.
  
  

7.3-Liter Power Stroke

• The 7.3 IDI was replaced by the 7.3 Power Stroke in 1994, which used direct fuel injection, a turbocharger and was computer-controlled. Ford produced the revamped and turbocharged version to match GM's turbocharged 6.5-liter diesel and the famous Cummins turbocharged 5.9-liter diesel in Dodge pickup trucks. The 1994 7.3 direct injection Power Stroke had some clear differences compared with non-turbo 1988-1992 version, such as a 17.5-1 compression ratio, a 275 horsepower rate at 2,800 rpm and a much increased 525 pound-feet of torque at 1,600 rpm.