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Isuzu LG6 specs: 3.1L (189 ci) 6-cylinder, 89 x 84 mm (3.5039 x 3.3071 in) bore and stroke. Rated 120 hp, 1991–1994. Used in the Isuzu Pickup and Isuzu Rodeo.
The Isuzu 189ci (LG6) is oversquare — the 3.5039" bore exceeds the 3.3071" stroke by 6.0% — a layout that favors airflow and RPM over leverage at the crank. The 3.3071" stroke does not reach 4,000 ft/min of mean piston speed until about 7,250 RPM, so piston speed is not what limits this engine's revs — valvetrain and breathing are. Each of the 6 cylinders displaces 31.5 ci (516 cc).
4 factory variants share these dimensions, rated at 120 hp across 1991–1994.
| Displacement | 189 ci / 3.1 L |
|---|---|
| Bore | 3.5039" |
| Stroke | 3.3071" |
| Cylinders | 6 |
| Configuration | V6 |
| Bore/stroke ratio | 1.06 |
| Fuel type | gas |
|---|---|
| Advertised HP | 120 hp |
| Years | 1991–1994 |
| Bore/stroke character | 1.060 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves |
|---|---|
| Mean piston speed at 6,000 RPM | 3,307 ft/min — conservative for a street engine |
| Displacement per cylinder | 31.5 ci |
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 |
|---|---|---|
| 1991 | — | LG6 |
| 1992 | — | LG6 |
| 1993 | — | LG6 |
| 1994 | 120 hp | LG6 |
2 factory vehicles, 1991–1994. Each year opens that model's engine table.