I finally got around to measuring a factory coolant bottle with that fitting... its a 2" diameter with a 10 pitch outside thread. Im going to go back through Gregs link but I don't think I've seen anything fitting that. I should search on a diesel forum since they seem to like their billet degas tanks... but most of them I've seen have switched over to a standard rad cap.


I just called Moroso because they had a Mustang coolant tank with the bung. They sold me 2 for $10 each. I'll have them in a couple days.

GTFO really? Thats cheaper than the bung..... whats the part number on that tank?

Hysterical!! Go figure.

LMFAO!!! No.. the bungs were $10 each... not the tank!!!

Sean, I'm curious now.

Are you replicating an existing tank? How did you math your way into sizing the tank? I have to admit, this seems like a better way of doing things and solves a couple of other issues as well. I also like that the cap is a 21 lb.

I tried to see inside the tank on the new mustang but I can't determine what is in there but would love to see what you have planned. Thinking about buying the moroso tank just to see.

Found some interesting info in this article regarding tank sizing.

https://www.cumminspower.com/www/lit...30_p93-115.pdf

We all know coolant expands when it warms up but an actual number wasn't readily available....at least to me. It seems that 6-7% of system volume is generally accepted as volume required for expansion. That is for an overflow tank or a degas tank.

A degas tank should have a volume of 17% of the total system. 6% for the above mentioned expansion and 11% for coolant. They call it draw down capacity on page 95.

So lets assume 4 gallons of coolant in the system, not counting the tank. 17% of that is 2.7 qts, I like round numbers so 3 qts it is. 3 qts is approximately 175 cubic inches and that would be the proper size for a degas bottle/surge tank.

Right?.....

I would check with C&R...

Andrew