No start...timing good...leak test bad...need help

[NewArt]

As Byprodriver suggested, I don't think you have conducted your leakdown test according to Hoyle. Make sure you are at TDC on the compression stroke for each cylinder. Otherwise you may have a valve partially open resulting in false readings. Also, it is not accurate to do this test on a cold engine.
Ah, okay, I see that you have answered back while I was typing. Still the cold engine thing though. The rings won't make a good seal.

[Jamesp]

After rebuilding my engine I blew the valve timing and tried to start the engine. I cranked and cranked with my valve timing off. When I realized what I had done, I got that sinking feeling that I just ruined a fresh rebuild. So after taking the engine back out of the car, dumping one head and finding the valves had not hit the pistons I performed a leak down test on every cylinder. Getting the valves to seal properly required me to turn the engine a few degrees counter clockwise around top dead center. There was a huge difference over couple of degrees in sealing or not sealing the valves. Can anyone tell me what the downside of rolling the engine counterclockwise is? I've never understood what breaks if that is done.