Compression readings are diff everytime???HOT/WARM

[91orangeGST]

I just got done rebuilding my entire engine 4g63T. Bored out 20 over with new pistons, rings, bearings, etc. Anyway at about 400 miles I did a compression check and it had 145 across the board. Well Im at about 1200 miles and I did another check immediatly after running it and the numbers were 135 across the board. I then decided to do it 2 min later and they rose to 140 across the board? I thought if the engine is hot the compression will be higher. WHats up with the numbers, also will you have lower compression when you bore an engine 20 over??? any info will help!

Kyle

 

[91orangeGST]

Just did it again and its at 145 across the board. What do you guys think about these numbers???

 

[oldman]

Just did it again and its at 145 across the board. What do you guys think about these numbers???

Full throttle during cranking right? I would suggest trying another know working gauge.

 

[91orangeGST]

yeah i did it with WOT.