6.9L IDI Diesel
The Foundation of the Ford/International Partnership
International began development of the 6.9L IDI diesel in 1978. It was not until 1983 that Ford offered the 6.9L in its 3/4 & 1 ton trucks (the International/Ford partnership was created in 1982). Displacing 420 cubic inches, the natually aspirated (no turbocharger) diesel offered peak torque ratings in 1986, producing 170 horsepower & 315 lb-ft. of torque at a extremely low 1,400 RPM. The 6.9L is known for being simple in design & making torque low in the powerband, both large feats for a V8 diesel. Though the performance of the 6.9L seems low by today's standards, it was a solid performer during its time & has a history of reliability/dependability. Furthermore, the 6.9L IDI became an iconic engine in the diesel industry & helped reshape tarnished image of diesel trucks.
6.9L IDI Specs:
Manufacturer: |
International Harvester |
Production Years: |
1983-1987 (for Ford Trucks) |
Applications: |
Ford F250, F350 |
Configuration: |
V-8 |
Block/Head Material: |
Cast iron block & heads |
Displacement: |
420 cubic inches, 6.9 liters |
Compression: |
20.7:1 (1983) 21.5:1 (1984+) |
Bore: |
4.00 inches |
Stroke: |
4.18 inches |
Injection: |
indirect injection (IDI), Stanadyne rotary pump |
Aspiration: |
naturally aspirated, non-turbo |
Weight: |
860 lbs. (approx) |
Peak Horsepower: |
170 HP @ 3,300 RPM |
Peak Torque: |
338 lb-ft. @ 1,400 RPM |
Reputation: |
Reliable, durable, powerful for time period |
Additional 6.9 L Information:
• The 6.9L was bored out to 7.3L in 1987, eliminating it from the engine line-up in 1988.
• The 7.3L & 6.9L are almost completely identical in design, except that the bore of the 7.3L was increased to 4.11 inches.
• The heart of the injection system on the 6.9L was a Stanadyne DB2 rotary injection pump.
• By the time the 6.9L reached production, engineers had tested the design for a combined 52,000 hours, and racked up 815,000 miles worth of field testing.

International 6.9L Diesel
- Related Topics: