See other engines in this family
Chevrolet LR4 specs: 293 ci (4.8L) 8-cylinder, 3.78 x 3.268 in (96 x 83 mm) bore and stroke. Rated 255-285 hp, 1999–2007.
The Chevrolet LS (LR4) is oversquare — the 3.7799" bore exceeds the 3.2677" stroke by 15.7% — a layout that favors airflow and RPM over leverage at the crank. The 3.2677" stroke does not reach 4,000 ft/min of mean piston speed until about 7,350 RPM, so piston speed is not what limits this engine's revs — valvetrain and breathing are. Each of the 8 cylinders displaces 36.6 ci (600 cc).
It is one of 57 engines in the LS family, the smallest at 293 ci. 13 factory variants share these dimensions, rated from 255 to 285 hp across 1999–2007.
| Displacement | 293 ci / 4.8 L |
|---|---|
| Bore | 3.7799" |
| Stroke | 3.2677" |
| Cylinders | 8 |
| Configuration | V8 |
| Bore/stroke ratio | 1.157 |
| Block material | cast iron |
|---|---|
| Head material | aluminum |
| Valvetrain | OHV |
| Fuel type | gas |
| Advertised HP | 255–285 hp |
| Years | 1999–2007 |
| Bore/stroke character | 1.157 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves |
|---|---|
| Mean piston speed at 6,000 RPM | 3,268 ft/min — conservative for a street engine |
| Displacement per cylinder | 36.6 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 |
|---|---|---|
| 1999 | 255 hp | LR4 |
| 2000 | 270 hp | LR4 |
| 2000 | 275 hp | LR4 |
| 2001 | 270 hp | LR4 |
| 2001 | 275 hp | LR4 |
| 2002 | 270 hp | LR4 |
| 2002 | 275 hp | LR4 |
| 2003 | 270 hp | LR4 |
| 2003 | 275 hp | LR4 |
| 2004 | 285 hp | LR4 |
| 2005 | 285 hp | LR4 |
| 2006 | 285 hp | LR4 |
| 2007 | 285 hp | LR4 |