Compression Check

Alldata Editors Note - Ford does not provide a cranking pressure specification, only an acceptable range.

Compression Test - Test Results
In stall an auxiliary starter switch to the starting circuit. With the ignition switch in the OFF position, crank the engine a consistent number of strokes (minimum of 2 compression strokes to 12 compression strokes). Record the readings.
Repeat the test on each cylinder, cranking the engine the same number of compression strokes, record the readings. Compare the readings of the 8 cylinders.
The indicated compression pressures are considered within specification if the lowest reading cylinder is at least 10% of the highest reading.