After boosting for 1,000 miles or so, I adjusted the valves and tested the compression on my motor. The results were 210, 210, 210, 195. I tested it twice, to make sure the #'s were accurate.

I tested the compression again, this time after running some regane in the tank to get rid of any excess carbon buildup. The numbers I got were strange. 210, 220, 230!, 195. What is up with the 230? I tested again and got the same numbers. My motor has 72,000 miles on it, stock 9.8 compression.

 

Conditions of when the comp. tests were taken will account for the changes in the results.

I'm assuming you did the first comp. test rigth after you did the valve adjustment? If so, the motor was probably cold (your suppose to adjust the valve on a cold motor) therefore the oil in the cylinders have probably mostly run off the walls and piston skirts. Therefore you would have gotten lower comp. test results.

The second test you did was probably right after you drove it around. Oil on the cylinder walls and piston rings would seal the compression better therefore higher test results.

HTH