I installed my 280H Comp cam with My Vortec heads, adjusted the valves exactly like Comp said to & now I think I have 5 bent valves. I turned the motor until the exhaust valve was just opening, turned the intake to zero lash & gave it 1/2 turn. Then turn the engine until the intake is half way closed & set the exhaust. I buttoned up the engine & cranked it with no fire. I checked all the cylinders & suddenly 1,3,5,7 & 2 all have no compression. I backed off all the rockers so the valves are all closed & pressured up each cylinder with air & they leak out the exhaust. How could I have bent those valves? Wouldnt they have hit when turning the engine by hand to adjust them? I have flat 4 valve relief pistons & I would think I would have to over tighten the rockers sooo much to even get close. I did have compression while adjusting the valves with the intake off, it had to happen while cranking the motor. Any ideas??