See other engines in this family
Buick LC9 specs: 196 ci (3.2L) 6-cylinder, 3.50 x 3.40 in (88.9 x 86.4 mm) bore and stroke. Rated 90 hp, 1978. Used in the Buick Regal. OHV.
The Buick 196ci (LC9) is close to square: 3.5" bore against 3.4" stroke, within 2.9%, which splits the difference between a high-revving layout and a torque layout. The 3.4" stroke does not reach 4,000 ft/min of mean piston speed until about 7,050 RPM, so piston speed is not what limits this engine's revs — valvetrain and breathing are. A rod ratio of 1.753 is long by production standards — less side-load on the cylinder wall and gentler piston acceleration around TDC, the geometry that tolerates high RPM. Each of the 6 cylinders displaces 32.7 ci (535 cc).
It is one of 2 engines in the Buick 196ci family, all of them 196 ci — the differences between them are in compression, heads and rating, not displacement.
| Displacement | 196 ci / 3.2 L |
|---|---|
| Bore | 3.5" |
| Stroke | 3.4" |
| Cylinders | 6 |
| Configuration | V6 |
| Rod length | 5.96" |
| Rod ratio | 1.753 |
| Bore/stroke ratio | 1.029 |
| Block material | cast iron |
|---|---|
| Head material | cast iron |
| Valvetrain | OHV |
| Fuel type | gas |
| Advertised HP | 90 hp |
| Years | 1978 |
| Bore/stroke character | 1.029 — square — bore and stroke are within 5%, a balanced compromise |
|---|---|
| Mean piston speed at 6,000 RPM | 3,400 ft/min — conservative for a street engine |
| Rod ratio | 1.753 — long — less side loading on the cylinder wall, favours high RPM |
| Displacement per cylinder | 32.7 ci |
Each link opens the calculator with this engine's specs already filled in.