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Pontiac 140ci (1976–1977) specs: 140 ci (2.3L) 4-cylinder, 3.501 x 3.625 in (88.9 x 92.1 mm) bore and stroke, 8:1 compression. Built 1976–1977.
The Pontiac 140ci (1976–1977) is close to square: 3.501" bore against 3.625" stroke, within 3.4%, which splits the difference between a high-revving layout and a torque layout. The 3.625" stroke puts mean piston speed at 4,000 ft/min around 6,600 RPM, which is where a production bottom end is generally considered at its limit. A rod ratio of 1.572 is in the range most production engines fall in. Each of the 4 cylinders displaces 35.0 ci (574 cc).
8:1 on iron heads is low by modern standards and generally happy on regular pump fuel.
It is one of 2 engines in the Pontiac 140ci family, all of them 140 ci — the differences between them are in compression, heads and rating, not displacement. 2 factory variants share these dimensions across 1976–1977.
| Displacement | 140 ci / 2.3 L |
|---|---|
| Bore | 3.501" |
| Stroke | 3.625" |
| Cylinders | 4 |
| Configuration | I4 |
| Compression ratio | 8:1 |
| Rod length | 5.7" |
| Rod ratio | 1.572 |
| Bore/stroke ratio | 0.966 |
| Block material | cast iron |
|---|---|
| Head material | cast iron |
| Valvetrain | OHV |
| Fuel type | gas |
| Years | 1976–1977 |
| Bore/stroke character | 0.966 — square — bore and stroke are within 5%, a balanced compromise |
|---|---|
| Mean piston speed at 6,000 RPM | 3,625 ft/min — in the range typical of performance street engines |
| Rod ratio | 1.572 — moderate — the range most production V8s fall in |
| Displacement per cylinder | 35.0 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 |
|---|---|---|
| 1976 | — | — |
| 1977 | — | — |
1 factory vehicle, 1976–1977. Each year opens that model's engine table.