compression variance

There are a whole series of posts here and on the Daytona Registry that detail the numbers. But, those normal readings reflect a motor that has been regularly exercised; garage queens can develop stuck rings, valves etc, some of which can (not always) resolve with 500 or more highway miles. M

 

Michael is certainly right on the money. There shouldn't be more than 10% between cylinders on a compression test, the leak down test in theory should not have any drop in pressure once air pressure is applied with both intake and exhaust valves closed. However, a small amount with air being heard in the exhaust or the intake is somewhat common. Consistent readings between cylinders is what you need to look for, provided they are within the normal factory sepcs.