I attempted a heater bypass today...and now water shoots out of the overflow hose that comes out of the expansion tank.

Here's what I did:
I put a length of hose from where the short elbow-shaped hose (pipe to control valve) was prior....and brought it around the passenger-side of the motor and attached it directly into the water pump (by pass hose pump to water pipe)...completely bypassing and removing the metal water pipe that is attached to the valve cover.
It seems like there is a pressure build up that is causing the water to spew out the overflow. Should I have left the valve in place and bypassed AFTER the valve? Should I have left the water pipe in place? What did I do wrong?
Thanks

Sounds like you pressurised the cooling system. I'm guessing the valve issue or the head is warped and pressurising the system that way.

I was just outside with the car running for a while until it warmed up and the fan kicked in...and no water spilled. Maybe the system was bleeding when I started it the first time?

Here's a diagram of the system. What I did was put a hose from 12 directly to 14. Does this seem right?
www.944online.com/cgi-bin/ASI_Store.cgi?...41+watercooling-9441