See other engines in this family
Jeep ESG specs: 392 ci (6.4L) 8-cylinder, 4.091 x 3.72 in (103.9 x 94.5 mm) bore and stroke, 10.9:1 compression. Rated 470 hp. Rod ratio and piston speed.
The Jeep HEMI (ESG) is oversquare — the 4.0906" bore exceeds the 3.7205" stroke by 9.9% — a layout that favors airflow and RPM over leverage at the crank. The 3.7205" stroke puts mean piston speed at 4,000 ft/min around 6,450 RPM, which is where a production bottom end is generally considered at its limit. Each of the 8 cylinders displaces 49.0 ci (803 cc).
10.9:1 on aluminum heads is in the range that usually runs on pump premium; aluminum sheds heat faster than iron, which makes the same number a little more forgiving.
It is one of 8 engines in the HEMI family, the largest at 392 ci. Factory fitments include the Grand Cherokee SRT, Wrangler Rubicon 392, Grand Wagoneer.
| Displacement | 392 ci / 6.4 L |
|---|---|
| Bore | 4.0906" |
| Stroke | 3.7205" |
| Cylinders | 8 |
| Compression ratio | 10.9:1 |
| Bore/stroke ratio | 1.099 |
| Block material | cast iron |
|---|---|
| Head material | aluminum |
| Valvetrain | OHV |
| Fuel type | gas |
| Advertised HP | 470 hp |
| Bore/stroke character | 1.099 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves |
|---|---|
| Mean piston speed at 6,000 RPM | 3,721 ft/min — in the range typical of performance street engines |
| Displacement per cylinder | 49.0 ci |
| Static compression | 10.9:1 — in the range that usually runs on pump premium |
Each link opens the calculator with this engine's specs already filled in.