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Porsche 589 specs: 1.3L (78 ci) 4-cylinder, 74.5 x 74 mm (2.9331 x 2.9134 in) bore and stroke. Rated 60 hp, 1954–1957. Used in the Porsche 356.
The Porsche 78ci (589) is close to square: 2.9331" bore against 2.9134" stroke, within 0.7%, which splits the difference between a high-revving layout and a torque layout. The 2.9134" stroke does not reach 4,000 ft/min of mean piston speed until about 8,250 RPM, so piston speed is not what limits this engine's revs — valvetrain and breathing are. Each of the 4 cylinders displaces 19.5 ci (320 cc).
It is one of 2 engines in the Porsche 78ci family, all of them 78 ci — the differences between them are in compression, heads and rating, not displacement. 4 factory variants share these dimensions, rated at 60 hp across 1954–1957.
| Displacement | 78 ci / 1.3 L |
|---|---|
| Bore | 2.9331" |
| Stroke | 2.9134" |
| Cylinders | 4 |
| Bore/stroke ratio | 1.007 |
| Fuel type | gas |
|---|---|
| Advertised HP | 60 hp |
| Years | 1954–1957 |
| Bore/stroke character | 1.007 — square — bore and stroke are within 5%, a balanced compromise |
|---|---|
| Mean piston speed at 6,000 RPM | 2,913 ft/min — conservative for a street engine |
| Displacement per cylinder | 19.5 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 |
|---|---|---|
| 1954 | 60 hp | 589 |
| 1955 | 60 hp | 589 |
| 1956 | 60 hp | 589 |
| 1957 | 60 hp | 589 |
1 factory vehicle, 1954–1957. Each year opens that model's engine table.