Greenhorn cooling system question

[UpNorth]

If you look at the picture attached am I right when I say that I have to screw in the expansion tank the two parts in between tank and hose.
Then I must run a hose between the filling cap and the short part that I screwed in the overflow tank.

And then what should I do with the other long part screwed in the expansion tank? Is it just going to let the over overflow run to the ground?

And should the cap of the expansion tank as high or lower than the filler cap. I think I understand that this should be the highest point of the cooling system in order to avoid air in the cooling system.

Thanks in advance and sorry for the trivial questions.

125754

[Alphamacaroon]

As far as I understand it (because the instructions aren't clear), you are correct, and it's the way I did mine. The short fitting gets connected to the filler cap, and the long tube vents to atmosphere and allows for the tank to retain fluid then overflow if it reaches a certain height.

To be honest, I'm not sure if it really matters that it is the highest point because if your filler cap is sealed tightly and there is enough fluid in the overflow tank, there shouldn't be any way for air to get in. As long as the hole in the bottom of that tank that connects to the filler cap remains covered with liquid at all times, I don't know of a way for air to get in. I think the bigger problem is when the tank is undersized, it overflows a bunch at high temp, then when it cools and tries to suck everything back in, it dries up and pulls in a bunch of air instead. There are a lot of people who say that the tank is undersized and can lead to air sucking problems, but I figured I'd give it a try before I move on to something bigger. I'm pretty sure I'm right about the height of the tank, and it makes logical sense to me, but I'm not willing to stake my reputation on it, so please confirm with others if it sounds fishy to you.

Additionally, if you are hooking this up to a Coyote with a heater, it's almost impossible to get it higher than the heating hoses (which are the highest point of the cooling system).

[Alphamacaroon]

And to add to that, it's probably more important that your radiator filler cap is about as high as it can get, because it makes it easier for air trapped at the highest point to be burped into the overflow tank. But in reality there isn't much you can do there unless you buy one of these https://www.chasebays.com/products/chase-bays-raised-inline-filler-neck?variant=1598185373705&utm_medium=cpc&utm_source=google&utm_campaign=Google%20Shopping&gclid=CjwKCAjwpqv0BRABEiwA-TySwfZhGZJnSZecBpl8_GGoPn50spVN4L55QDWolN1tKbtth_7 abtk3ixoC2CYQAvD_BwE. In fact, if you are running a heater setup, the filler neck is almost completely useless for filling the system— you'll actually fill the coolant from the highest possible point, the heater hoses.

Of course this assumes you are running Coyote power, but probably not that different with other engines as well. I'd also add that edwardb has an excellent writeup on a system where you throw this tank away and plumb it more (or exactly like) the stock Coyote cooling setup.

[UpNorth]

Ok thanks guys.
I’m running a 347 f.i. from Blue Print Engines.

[GSides9]

The hose from the radiator cap gets hooked to the piece with the long tube attached. The short fitting gets a hose attached so the overflow doesn't get on your tires. It works like this. Antifreeze expands in the radiator with heat and gets pushed out the radiator cap and into the coolant recovery can. When it cools and contracts it creates a small vacuum and draws the antifreeze back in. If you hook it up backwards, you suck air in. Our coolant recovery can was too small and kept pushing antifreeze out on the ground. With the radiator full and cold, you just want a little antifreeze in the recovery tank.

[David Williamson]

The small tank was OK for my 302 mustang engine in the Cobra but I had to get a larger one for my Dart 363 in the Coupe. I think the Dart block has larger cooling passages so more fluid than the stock Ford blocks.
David W

[Alphamacaroon]

The hose from the radiator cap gets hooked to the piece with the long tube attached. The short fitting gets a hose attached so the overflow doesn't get on your tires.

GSides9, did you maybe mean to say the opposite? I'm pretty sure the short fitting does not get connected to a drain/overflow hose, otherwise the tank wouldn't hold any coolant at all— it would be the lowest drain point in the tank and would drain to the ground the moment any coolant emptied into it.

[GSides9]

Sorry Gents,

I thought the fittings screwed into the top of the tank. I thought the long tube was going to the bottom of the tank. Obviously I was wrong. Thanks for catching my mistake.

Glen

[Alphamacaroon]

Sorry Gents,

I thought the fittings screwed into the top of the tank. I thought the long tube was going to the bottom of the tank. Obviously I was wrong. Thanks for catching my mistake.

Glen

No problem. Although I never thought of that— if it was mounted upside down like the picture shows, then (other than the small hole in the cap) it probably would work exactly the way you described it! So it was just a different point of perspective. :D