It's dead easy to bleed the air from the system using the little bolt
on the top of the hose fitting (its the highest point of the cooling
circuit).  Just open it up until water comes out.  I then started the
car, and over a few minutes while it warmed up, I carefully bled out
more air that found its way up to the bleed screw.

If I was you, I would get a thermostat put in.  It's like that other
chap said, a removed thermostat could quite possibly make it run hot
rather than cold, it just depends how the circuit is designed.  

Or maybe your radiator is clogged up with sediment??

Keith.