I gotcha, and you're not wrong! I just try too hard to be different and sometimes gets me in a little trouble! 😉 Hahah.

I do have a coolant overflow bottle! It'll spit coolant out of the neck, fill the overflow, then will suck back in like it suppose to do. Problem is I just lose too much coolant when it spits it out.

I'm thinking welding an aluminum 90 degree elbow piece of tubing to the top tank and fill it there. Also put a plug on it, and loosen the plug to let air out while burping the system

Not a bad idea. I think I'm going to get an aluminum 90 degrees elbow to weld to the top tank and fill it there. Help get all of the air out and just never take the cap off the current fill spot. Thank you for the advice!

My unasked for opinion is the simplest all around best looking system is the one the car came with. Any other system only adds more unnecessary clutter and results in a system that doesn't work as well as prior to the modification. I have a mostly original (sheet metal wise) Y-block powered 32 5w, see the radiator and all every day. I see nothing objectionable about the original form. Still using an original radiator by the way.  

The glass T-bucket I had was a Total Performance unit from before the sale to Speedway. Apparently they had the same idea of cleaning up the top of the shell also. Didn't work there either. The way I fixed it, with the cap I used, the top of cap was barely above the top of the shell. Actually was cleaner looking than before because there was no filler neck sticking out the back of the expansion tank. And I was able to have probably about 1 1/2 quarts more coolant in the system. 

The original type system was better on every count in my book. 

"But I also must say my filling point is lower than the radiator. The system my dad and I designed is different. It has a separate filling reservoir. I don't fill up the top tank on the radiator. So I'm thinking I'm getting a little steam bubble up too and it pushes out the coolant when I turn up the RPMS. So I think I'm planning on putting some kind of bleeder or plug on the top tank to be able to let air out."

Do you have a coolant overflow/recovery tank in the system in addition to the expansion tank shown?

It would be a shame to have to remove that expansion tank (the inline filler mentioned is the quickest out without having to modify the grille shell).

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Cool thought, but it doesn’t seem to be working. How about something like this, it would just require some hose work. If it solves the problem you could work out a solution you liked better.

https://www.jegs.com/i/JEGS/555/53098/10002/-1?CAWELAID=1710676818&CAGPSPN=pla&CAAGID=39714413703&CATCI=pla-457013475083&CATARGETID=230006180040357466&cadevice=t&jegspromo=nonbrand&gclid=EAIaIQobChMIxd-B7d7K3AIVBcpkCh2BCwtQEAQYESABEgJGlPD_BwE



miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

Usually the top of remote expansion tanks are a little higher than the top of the radiator, so that the level of the liquid in the tank is equal to the level of the liquid in the radiator. So that the pressure builds in the upper part of the expansion tank, underneath the cap. Just like it would if the expansion tank was at the top of the radiator like they used to be. There has to be room somewhere for expansion of the coolant. It is no tiny amount. Your tank is mostly just part of the coolant system. Looks like little to no room for expansion once the normal level of the coolant fills most of the tank.

Right, that's what I'm thinking it is. So you think a steam pocket is causing it to push out coolant then? All of this was custom fabricated by my dad and I, just weren't thinking about that when we made it! Haha oh well, not that big of a deal to put a filler on the top tank

Sorry, but that system is designed to leak. Speedway used to sell (maybe still does) T-bucket radiator and shells designed similar to that, without the tank yours has. The bottom of the fill tube was right at the bottom of the expansion tank. It would leak a little every time the engine got warm. I fixed it by putting the filler at the top of the radiator, accessible through a hole in the top of the shell. Like they were designed.

The cap needs to be above the highest point of the system, with a little room for expansion. Wherever it is located.

The coolant in your system is under pressure out the cap because it sure appears to be about level with the upper level of the coolant in the radiator. It's just doing the only thing it can do. Liquids don't compress. The pressurized pocket above the cap is pushing the liquid out.

Probably nothing wrong with anything else

That first one looks all weird haha