How do you fill the cooling system after a cam replacement? I guess you need to make sure the water pump is flooded, or won't the pump be airbound? After starting the engine won't the themrostat take a while to open up, will I need to add more coolent at this point?
Never did think about this part too much!
Cheers
Andy

 

I simply filled my radiator and started the engine. Watched the radiator and added coolant/water as the level dropped. There was some air in the system that burped out over a day or so and was replaced by the coolant in the overflow tank.

 

I like to take the coolant temp sending unit out and fill it until coolant comes out. You won't have much air trapped then. Be careful not to break it.

 

One way I like to use is to get the front end up, on ramps, jack stands, whatever so that the radiator cap is up high. Then the air bubbles/pockets that are trapped in the heads or intake manifold will work their way to the top of the radiator and into the overflow container. Keep adding coolent as need.

Some people like to do this with the cap off and the car level but I think it's best to have the system capped when getting the air out. The problem is that if you rev the engine with the cap off then you are apt to loose coolent out the open neck.... makes a bigger mess.

 

My only radiator cap is on the expansion tank, not on the radiator, and filling through just the expasion tank is almost impossible. So, I use a short piece of heater hose connected to the heater hose connection that goes into the top of intake manifold. Works Great.

 

I always fill mine through the filler neck and have never had coolant spill out of the filler neck when revving.
Also, the thermostat is already the highest point in the coolant flow on the engine so no need to jack up the car. And the air will become entrained in the coolant flow anyway. Just make sure to check the level after the thermostat has been fully open at least once.
A final trick...drill a 1/8" hole in the thermostat flange. This will allow air to bleed out even before the thermostat opens. I have done that for years, makes refilling easy. I am currently running a Stewart bypass type thermostat, which is the same concept only the hole is a little bigger.
Also, you should always use distilled water in your radiator to prevent buildup of deposits in your cooling system from the minerals that naturally occur in tap water.
Jeff