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
Info took from [Only admins are allowed to see this link]
Home 
