Engine Compression
When making compression checks, disconnect ignition switch connector (Pink wire) from High Energy Ignition (HEI) system. With air cleaner removed, throttle wide open, and all spark plugs removed, crank engine through at least 4 compression strokes.
COMPRESSION SPECIFICATIONS
| Application | Specification | |
|---|---|---|
| Compression Ratio | ||
| 5.0L | 9. 3:1 | |
| 5.7L | 8. 3:1 | |
| 7.4L | 7. 9:1 | |
| Compression Pressure | 150 psi (10.5 kg/cm2) | |
| Maximum Variation Between Cylinders | 30% | |