Folks. I just rebuilt and installed my sons 2008 3.8l engine. After it wouldn't start I ran a compression check. Numbers 1, 2,and 3 have no compression while numbers 4, 5, and 6 have a rock solid 110 psi. Given the heads are good, the pistons are new it points to cam timing. I set the cam with the #1 cylinder (passenger side front piston) on TDC. This positioned the crank gear mark on top. I aligned the cam mark on the bottom center with the arrow facing down pointing to the crank gear mark. Any help or ideas appreciated.