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Mitsubishi G64B specs: 2.4L (146 ci) 4-cylinder, 86.5 x 100 mm (3.4055 x 3.9370 in) bore and stroke, 8.5:1 compression. Built 1985–1987.
The Mitsubishi G64B is undersquare — the 3.937" stroke exceeds the 3.4055" bore by 13.5% — a layout that trades peak RPM for leverage and torque low in the range. The 3.937" stroke puts mean piston speed at 4,000 ft/min around 6,100 RPM, which is where a production bottom end is generally considered at its limit. Each of the 4 cylinders displaces 36.5 ci (598 cc).
8.5:1 is low by modern standards and generally happy on regular pump fuel.
It is one of 5 engines in the Mitsubishi 146ci family, all of them 146 ci — the differences between them are in compression, heads and rating, not displacement. 3 factory variants share these dimensions across 1985–1987.
| Displacement | 146 ci / 2.4 L |
|---|---|
| Bore | 3.4055" |
| Stroke | 3.937" |
| Cylinders | 4 |
| Configuration | I4 |
| Compression ratio | 8.5:1 * |
| Bore/stroke ratio | 0.865 |
* Compression ratio from a single source; not yet cross-verified.
| Fuel type | gas |
|---|---|
| Years | 1985–1987 |
| Bore/stroke character | 0.865 — undersquare — stroke exceeds bore, which favours low-end torque |
|---|---|
| Mean piston speed at 6,000 RPM | 3,937 ft/min — in the range typical of performance street engines |
| Displacement per cylinder | 36.5 ci |
| Static compression | 8.5:1 — low by modern standards, generally happy on regular pump fuel |
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 |
|---|---|---|
| 1985 | — | G64B |
| 1986 | — | G64B |
| 1987 | — | G64B |
1 factory vehicle, 1985–1987. Each year opens that model's engine table.