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Mercedes-Benz M100 specs: 6.8L (417 ci) 8-cylinder, 107 x 95 mm (4.2126 x 3.7402 in) bore and stroke, 8:1 compression. Built 1978–1979.
The Mercedes-Benz M100 is oversquare — the 4.2126" bore exceeds the 3.7402" stroke by 12.6% — a layout that favors airflow and RPM over leverage at the crank. The 3.7402" stroke puts mean piston speed at 4,000 ft/min around 6,400 RPM, which is where a production bottom end is generally considered at its limit. Each of the 8 cylinders displaces 52.1 ci (854 cc).
8:1 is low by modern standards and generally happy on regular pump fuel.
2 factory variants share these dimensions across 1978–1979.
| Displacement | 417 ci / 6.8 L |
|---|---|
| Bore | 4.2126" |
| Stroke | 3.7402" |
| Cylinders | 8 |
| Configuration | V8 |
| Compression ratio | 8:1 * |
| Bore/stroke ratio | 1.126 |
* Compression ratio from a single source; not yet cross-verified.
| Fuel type | gas |
|---|---|
| Years | 1978–1979 |
| Bore/stroke character | 1.126 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves |
|---|---|
| Mean piston speed at 6,000 RPM | 3,740 ft/min — in the range typical of performance street engines |
| Displacement per cylinder | 52.1 ci |
| Static compression | 8:1 — 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 |
|---|---|---|
| 1978 | — | M100 |
| 1979 | — | M100 |
1 factory vehicle, 1978–1979. Each year opens that model's engine table.