During compression test, engine must be at normal operating temperature, all spark plugs removed, and throttle valve must be in WOT position. See COMPRESSION SPECIFICATIONS table. Crank engine through 4 or more compression strokes.
| Application | Compression Ratio | |
|---|---|---|
| 4.5L | 9.0:1 | |
| 5.0L (VIN E) TBI | 9.3:1 | |
| 5.0L (VIN F) TPI | 9.0:1 | |
| 5.0L (VIN Y) 4-Bbl. | 8.0:1 | |
| 5.7L (VIN 7) TBI (Police) | 8.2:1 | |
| 5.7L (VIN 8) TPI F Body | 9.3:1 | |
| 5.7L (VIN 8) TPI Y Body | 9.5:1 | |
| Compression Pressure | ||
| 4.5L | 140-165 (9.8-11.6 kg/cm 2 ) | |
| All Others (Min.) | 100 psi (7.0 kg/cm 2 ) | |
| Maximum Variation Between Cylinders | 30% | |
COMPRESSION SPECIFICATIONS