See other engines in this family
Pontiac 140ci (1975) · 87 hp specs: 140 ci (2.3L) 4-cylinder, 3.501 x 3.625 in (88.9 x 92.1 mm) bore and stroke, 9.501:1 compression. Rated 87 hp, 1975. OHV.
The Pontiac 140ci (1975) · 87 hp 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).
9.501:1 on iron heads is in the range that usually runs on pump premium; iron holds heat, so treat it as the less forgiving side of that range.
| Displacement | 140 ci / 2.3 L |
|---|---|
| Bore | 3.501" |
| Stroke | 3.625" |
| Cylinders | 4 |
| Configuration | I4 |
| Compression ratio | 9.501:1 |
| 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 |
| Advertised HP | 87 hp |
| Years | 1975 |
| 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 | 9.501:1 — in the range that usually runs on pump premium |
| Intake valve diameter | 1.625" |
|---|---|
| Exhaust valve diameter | 1.38" |
Each link opens the calculator with this engine's specs already filled in.