See other engines in this family
Pontiac L14 specs: 307 ci 8-cylinder, 3.875 x 3.25 in (98.4 x 82.6 mm) bore and stroke, 8.5:1 compression. Built 1971–1972. Used in the Chevrolet C/K Pickup.
The Pontiac 307ci (L14) is oversquare — the 3.875" bore exceeds the 3.25" stroke by 19.2% — a layout that favors airflow and RPM over leverage at the crank. The 3.25" stroke does not reach 4,000 ft/min of mean piston speed until about 7,400 RPM, so piston speed is not what limits this engine's revs — valvetrain and breathing are. Each of the 8 cylinders displaces 38.4 ci (629 cc).
8.5:1 is low by modern standards and generally happy on regular pump fuel.
It is one of 3 engines in the Pontiac 307ci family, all of them 307 ci — the differences between them are in compression, heads and rating, not displacement. 2 factory variants share these dimensions across 1971–1972.
| Displacement | 307 ci |
|---|---|
| Bore | 3.875" |
| Stroke | 3.25" |
| Cylinders | 8 |
| Configuration | V8 |
| Compression ratio | 8.5:1 |
| Bore/stroke ratio | 1.192 |
| Fuel type | gas |
|---|---|
| Years | 1971–1972 |
| Bore/stroke character | 1.192 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves |
|---|---|
| Mean piston speed at 6,000 RPM | 3,250 ft/min — conservative for a street engine |
| Displacement per cylinder | 38.4 ci |
| Static compression | 8.5:1 — 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 |
|---|---|---|
| 1971 | — | L14 |
| 1972 | — | L14 |
12 factory vehicles, 1968–1973. Each year opens that model's engine table.