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Ford 7.3L diesel specs: 443.6 ci (7.3L) 8-cylinder, 4.11 x 4.18 in (104.4 x 106.2 mm) bore and stroke, 21.5:1 compression. Rated 180 hp, 1988–1991.
The Ford 7.3L diesel is close to square: 4.11" bore against 4.18" stroke, within 1.7%, which splits the difference between a high-revving layout and a torque layout. The 4.18" stroke puts mean piston speed at 4,000 ft/min around 5,750 RPM, which is where a production bottom end is generally considered at its limit. Each of the 8 cylinders displaces 55.5 ci (909 cc).
At 21.5:1 this is a compression-ignition engine: the ratio is the heat source that lights the fuel, not a knock limit to be managed.
It is one of 7 engines in the IDI Diesel V8 family, the largest at 443.6 ci. 4 factory variants share these dimensions, rated at 180 hp across 1988–1991.
| Displacement | 443.6 ci / 7.3 L |
|---|---|
| Bore | 4.11" |
| Stroke | 4.18" |
| Cylinders | 8 |
| Configuration | V8 |
| Compression ratio | 21.5:1 |
| Bore/stroke ratio | 0.983 |
| Fuel type | diesel |
|---|---|
| Advertised HP | 180 hp |
| Years | 1988–1991 |
| Year | Version | HP @ rpm | Torque @ rpm | Comp. |
|---|---|---|---|---|
| 1990 | net | 180 @ 3300 | 345 lb-ft @ 1400 | 21.5:1 |
Factory specification sheet.
| Bore/stroke character | 0.983 — square — bore and stroke are within 5%, a balanced compromise |
|---|---|
| Mean piston speed at 6,000 RPM | 4,180 ft/min — in the range typical of performance street engines |
| Displacement per cylinder | 55.5 ci |
| Static compression | 21.5:1 — high enough that pump premium or better is normally required |
Each link opens the calculator with this engine's specs already filled in.
These records share identical bore, stroke, displacement and compression. They differ by model year and factory power rating.
| Year | Advertised HP | Code |
|---|---|---|
| 1988 | 180 hp | 7.3L diesel |
| 1989 | 180 hp | 7.3L diesel |
| 1990 | 180 hp | 7.3L diesel |
| 1991 | 180 hp | 7.3L diesel |
1 factory vehicle, 1988–1991. Each year opens that model's engine table.