Is an AST even needed if running Evans coolant? What about an overflow tank?
I have seen some weird cooling system set-ups in some of the Japanese cars posted on the web, no filler necks, no ast, etc...

 

Running evans has no effect of the AST.

 

I believe my friend, a track instructor, runs evans w/o an ast and uses zero pressure cap. From what I understand about evans it doesn't expand with heat or boil. If this is true pressure relief and air seperation is unnecessary once you get the air bubbles out of the system.

 

Evans expands and contracts even more then regular coolant/water. You almost need a larger overflow because it expands so much. Because of this I would also be more inclined to keep my AST.

 

I removed mine.....no problems at all....I don't have a thermostat in either. I need to call pineapple and get a 7psi pressure cap. I still have the stock one on.

 

If you haven't modified the thermostat housing appropriately, Put the thermostat back on. You'll thank me if it's not too late.

The thermostat housing is a bypass type. If you don't have a thermostat on 20-30% of the coolant will bypass right back into the block instead of going thru the radiator.

 

I ran evans w/o an AST and was fine, but if I had to do it again, I would keep the AST. Just for the extra coolant capacity.

 

The AST is not neede with any coolant!

Many of us here in Houston do not run the AST.
Wedo not have any problems.

 

If you load up with Evan's right after reinstalling your engine, beware! You must run the pressurized cap or you will not be able to purge all the air pockets out of the rear of the engine too easily. I was warming my car up for the first time and in a couple of minutes the temps shot through the roof on the stock gauge. Funny though the Haltech only read 185F. I had to start/stop the engine a few times for all the air to purge out. The last time I ran the pressurized cap for a week and had no problems. I am thinking the air-pocket was located in the rear housing because of the temp differences. It did not take too long for the temps to rise. I noticed it in time as to not cause coolant seal damage, thank God.