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Porsche 369 specs: 1.1L (66 ci) 4-cylinder, 73.5 x 64 mm (2.8937 x 2.5197 in) bore and stroke, 7:1 compression. Rated 40 hp, 1950–1954.
The Porsche 66ci (369) is oversquare — the 2.8937" bore exceeds the 2.5197" stroke by 14.8% — a layout that favors airflow and RPM over leverage at the crank. The 2.5197" stroke does not reach 4,000 ft/min of mean piston speed until about 9,500 RPM, so piston speed is not what limits this engine's revs — valvetrain and breathing are. Each of the 4 cylinders displaces 16.5 ci (270 cc).
7:1 is low by modern standards and generally happy on regular pump fuel.
5 factory variants share these dimensions, rated at 40 hp across 1950–1954.
| Displacement | 66 ci / 1.1 L |
|---|---|
| Bore | 2.8937" |
| Stroke | 2.5197" |
| Cylinders | 4 |
| Compression ratio | 7:1 |
| Bore/stroke ratio | 1.148 |
| Fuel type | gas |
|---|---|
| Advertised HP | 40 hp |
| Years | 1950–1954 |
| Bore/stroke character | 1.148 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves |
|---|---|
| Mean piston speed at 6,000 RPM | 2,520 ft/min — conservative for a street engine |
| Displacement per cylinder | 16.5 ci |
| Static compression | 7:1 — 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 |
|---|---|---|
| 1950 | 40 hp | 369 |
| 1951 | 40 hp | 369 |
| 1952 | 40 hp | 369 |
| 1953 | 40 hp | 369 |
| 1954 | 40 hp | 369 |
1 factory vehicle, 1950–1954. Each year opens that model's engine table.