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Isuzu GM 2.8 V6 specs: 2.8L (171 ci) 6-cylinder, 89 x 76 mm (3.5039 x 2.9921 in) bore and stroke. Built 1989–1991. Used in the Isuzu Trooper.
The Isuzu GM 2.8 V6 is oversquare — the 3.5039" bore exceeds the 2.9921" stroke by 17.1% — a layout that favors airflow and RPM over leverage at the crank. The 2.9921" stroke does not reach 4,000 ft/min of mean piston speed until about 8,000 RPM, so piston speed is not what limits this engine's revs — valvetrain and breathing are. Each of the 6 cylinders displaces 28.5 ci (467 cc).
3 factory variants share these dimensions across 1989–1991.
| Displacement | 171 ci / 2.8 L |
|---|---|
| Bore | 3.5039" |
| Stroke | 2.9921" |
| Cylinders | 6 |
| Configuration | V6 |
| Bore/stroke ratio | 1.171 |
| Fuel type | gas |
|---|---|
| Years | 1989–1991 |
| Bore/stroke character | 1.171 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves |
|---|---|
| Mean piston speed at 6,000 RPM | 2,992 ft/min — conservative for a street engine |
| Displacement per cylinder | 28.5 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 |
|---|---|---|
| 1989 | — | GM 2.8 V6 |
| 1990 | — | GM 2.8 V6 |
| 1991 | — | GM 2.8 V6 |
1 factory vehicle, 1989–1991. Each year opens that model's engine table.