So we just put this engine togather here's what it is

b18a1 bored to 81.50 all fresh
rs machine 81.50 ctr pistons (pct)
arp rod bolts
stock ls head

Ran a compression check on it and it came back 115 120 across the board
that being said i replaced the headgasket and still it was the same so the i replaced the head and another head gasket once again still 115 120 compression.The engine was put togather by a good friend of mine who has a **** load of great builds under his belt.we put the engine togather exactly to endyns specs messured everything prefect.
so thats what i have and there is no reason y its not making compression so any help would be great thanks guys

 

Assuming a good bottom end build, are you sure about your cam install/cam timing in the head?

 

When cranking was the engine at operating temp?? and also was the throttle fully open?>

 

once again....if you haven't made sure you're performing the test correctly, the test results will give poor results. Was the fuel system disabled? This can be accomplished by pulling the ECU fuse, the fuel pump fuse, disconnecting the injector clips, just to name a few things... The fuel system not being disabled is responsible for 99% of the low readings.