Coolant loss

[double ugly]

I have a 428 PI in my car with an expansion tank. I initially had a 200 degree thermostat in the system but was advised to put a 160 or 180 degree thermostat in the car. Since putting in a 160 thermostat after getting both water and oil up to normal limits,(70C) the expansion tank drain pukes out a half cup of coolant. I was assuming that since I filled the expansion tank to the limit initially, that some coolant on the floor would be normal. It still is puking after seven trips. I checked the expansion tank and there is no coolant in it but the car shows no sign of over heating. Any thoughts?????
John

[vettestr]

Hey John, Is it normal for your car to have an empty x tank? I respect the opinions of the FE crowd but would ask them to confirm the 160 * choice in Phx. It is my thought that a 160 in our heat will just remain open once all temps have reached their average high. in your big block. A 200 will cycle rather than just remain open but does not leave much cushion. The 180 is my choice as it should cycle and leaves that cushion for the extra long traffic lights and extra delays of heavy traffic.
I think you have gotten her hot and puked enough coolant that she is now sucking a little air. Fill her back up and make sure you get all the air out and watch very close to prove or disprove what I am thinking. Now that we are cooling down from the normal highs the 160* T-stat may work better. Our Valley of the Sun has special needs for these bad boy Toys.

[double ugly]

The water temp gets as high as 80C but normally runs at 70C. Hasn't gotten hot that I'm aware of.
John

[dan d]

For what it's worth I have an aluminum block 427, alum. heads, and intake. My expansion tank always has about 3/4 of an inch of water in it after a thorough (8 hour) cool down. Apparently that's the right level for this engine setup as it did spill coolant till it got to it's ideal level. After initially filling the radiator and the tank, did you heat up the engine so it's hot and remove the cap on the tank to let it burp the air out. Leaving the cap on will let the air coming up push coolant out the overflow, and you'll end up lower than your "ideal".

[Anthony]

I got one of those Summit, $14 white 1 qt overflow tanks, took the top off, and epoxied a vinyl hose from the top fitting such that it extends down into the base of the overflow tank, so that any fluid entering the tank will be deposited at the bottom, but more importantly, as the engine cools, as it sucks, it pulls any expelled fluid from the bottom of the overflow tank back into the expansion tank, through a 5/16 - 3/8 fuel line. It seems to be working fine, like a full recovery system should. The tank is tucked under my left front fender, mounted to the back of my inner fender.

[vettestr]

John,
What is the latest? Have you gotten a warm and fuzzy about everything yet? If not top off the coolant level to about 1/2 full in the X tank and watch her close to confirm no air in the system. Then let her cool down and re-check level. When done checking levels drive it like you stole it and enjoy.

[double ugly]

I just drove the car to West World for a display at the Good Guys car show. The temp did get up to 95C in the stop and go traffic. I haven't added any coolant yet but will top it off before driving it home Sunday PM.
John