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Mercedes-Benz M117.968 specs: 5.5L (339 ci) 8-cylinder, 96.5 x 94.8 mm (3.7992 x 3.7323 in) bore and stroke. Rated 238 hp, 1986–1991.
The Mercedes-Benz M117.968 is close to square: 3.7992" bore against 3.7323" stroke, within 1.8%, which splits the difference between a high-revving layout and a torque layout. The 3.7323" stroke puts mean piston speed at 4,000 ft/min around 6,450 RPM, which is where a production bottom end is generally considered at its limit. Each of the 8 cylinders displaces 42.4 ci (694 cc).
It is one of 2 engines in the Mercedes-Benz 339ci family, all of them 339 ci — the differences between them are in compression, heads and rating, not displacement. 6 factory variants share these dimensions, rated at 238 hp across 1986–1991.
| Displacement | 339 ci / 5.5 L |
|---|---|
| Bore | 3.7992" |
| Stroke | 3.7323" |
| Cylinders | 8 |
| Configuration | V8 |
| Compression ratio | 9–10:1 (published figures vary) |
| Bore/stroke ratio | 1.018 |
| Fuel type | gas |
|---|---|
| Advertised HP | 238 hp |
| Years | 1986–1991 |
| Bore/stroke character | 1.018 — square — bore and stroke are within 5%, a balanced compromise |
|---|---|
| Mean piston speed at 6,000 RPM | 3,732 ft/min — in the range typical of performance street engines |
| Displacement per cylinder | 42.4 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 |
|---|---|---|
| 1986 | 238 hp | M117.968 |
| 1987 | 238 hp | M117.968 |
| 1988 | 238 hp | M117.968 |
| 1989 | 238 hp | M117.968 |
| 1990 | 238 hp | M117.968 |
| 1991 | 238 hp | M117.968 |
1 factory vehicle, 1986–1991. Each year opens that model's engine table.