Overheating-Air Bubble in engine?

[compression]

I finally got to start my car for the first time since the complete motor rebuild (long story). But it heats up incredibly quick and doesnt cool down. I have removed the thermostat.Here is the method I am using to fill the engine with water. Remove bleed screw on upper radiator neck on the side of the head (behind cam sensor). Jackl up the front of the car as high as my jack will go. Fill the radiator until water comes out of the bleed screw. Install bleed screw. Keep filling until the radiator is full.I am not using a heater, I have a small 180degree bend to join the two heater pipes. Can anyone advise why there still may be an air bubble in the system, keeping the water from circulating?thanksp.s. this is in a datsun 510, not a 240sx.

[SpeedRacer1]

You could just run the engine until its hot. Turn the car off. Take off the radiator cap with a few towels for protection. Then when the steam stops coming out fill it up with more coolant on hand. If only coolant is coming out, close it, its already bled properly. Then next time you get a chance check the coolant.

[yellow_jacket]

What are you using to measure the temperature? Some people have had problems with their temp gauge not being compatible with the SR's sending unit.

If it is overheating though, run it with the cap off and the bleeder out. That it is heating up incredibly quick and not cooling down makes it seem like either the head gasket is severly blown(but you didn't mention any smoke or oil/coolant mixing) or a gauge malfunction issue.