Reply to "Overflow tank"

I have found that my operating temps are much more stable if I fill the the main, "surge tank" to the top, and the tall secondary tank, whatever we want to call it, about half way. Then once the operating temp is reached, the gauge doesn't bounce up and down.

It occurs to me though after what JFB posted about the expansion rate of the coolant, that if I reduce the level in the surge tank to allow for expansion there that the secondary tank becomes a "catch tank" rather than an "expansion tank".

The "book" says the entire system is 26 quarts. Who am I to argue? How much room do I need to leave in the surge tank for the expansion of that coolant if the secondary tank is only used as a "catch" can?



What I do not know now, is that if I do reduce the coolant level in the surge tank, will I be running hotter and the temps cycling up and down more? I don't like to see that in a coolant system. It gets me very nervous and makes me worry that there is a component failing or a hose is expanding and contracting and getting ready to pop?

I need to get the tall, 4" x 14" tank to a place where I can access it easily. The problem is is won't fit anywhere else. I need to substitute another tank for it in a location that is easily accessible when the engine is hot.

I have two possible candidates for that substitution.

This Moroso unit which is 1.4 quarts and fits the space

http://www.ebay.com/itm/151522...e=STRK%3AMEBIDX%3AIT

And this one that is 750ML (25 oz) but could be racked into a double or triple tank unit.

http://www.ebay.com/itm/161369...e=STRK%3AMEBIDX%3AIT

(I posted the links here simply because it is easier than posting pictures of them here with the 200 mega bite picture limits.)


So again, as far as I understand it, and I'm wrong or confused often, depending on how I fill the "surge" tank determines on whether or not the secondary tank is an "expansion" tank or a "catch" tank. Am I incorrect?


I have all of those tanks here now. I don't need to buy them.