the pistons should rock forward and aft to the engine layout. That is normal. The skirts on the pistons resist side-to-side movement from the crank pull/push. Even a fresh new Nissan motor will have some play in there.
If you don't see any scoring or chatter marks on the cylinder walls, then perhaps there is just a bit of bad sealing on the head?
It is worth using another gauge as well because I know some (like mine) read pretty low. I was getting just barely over 100psi on this motor, and only 170psi on my stock VE. I changed the compression tester and the 100psi turned into 145-150 across the board.
Checked a fresh DET and it had 155psi across the board with the factory pistons/ring gap. So I am in the clear now. Cylinder 2 was reading lower than the rest, but it has swallowed some plugs in the past lol. Minor piston pitting can be seen on the top of the piston when you take the plugs out. 5psi is negligible though. The motor runs like a raped ape.
If you don't see any scoring or chatter marks on the cylinder walls, then perhaps there is just a bit of bad sealing on the head?
It is worth using another gauge as well because I know some (like mine) read pretty low. I was getting just barely over 100psi on this motor, and only 170psi on my stock VE. I changed the compression tester and the 100psi turned into 145-150 across the board.
Checked a fresh DET and it had 155psi across the board with the factory pistons/ring gap. So I am in the clear now. Cylinder 2 was reading lower than the rest, but it has swallowed some plugs in the past lol. Minor piston pitting can be seen on the top of the piston when you take the plugs out. 5psi is negligible though. The motor runs like a raped ape.