[Munky]

So the 1970 Nova did not come factory with a coolant overflow tank (from what I have read). I noticed that my radiator always balances out to have about 2-3 inches of low coolant when cool. If I fill the radiator completely and drive it then it will puke out a fair bit upon stopping and parking the car. It would seem that running on overflow tank would give the coolant somewhere to go and I assume be sucked back into the radiator to maintain a full system. Is that the correct assumption?

Thinking about running a 1973 overflow tank or trying to find a smaller aluminum tank to mount down below the battery somehow. Has anyone ran something similar and have any recommendations?

I should note that my car is not overheating or running hot. Gets to the 180 (thermostat temp) and stays there until shutoff. Then it creeps up to around 200° before cooling off.

 

[RifRaf]

You are correct with your assumption.
I run a stock 1974 overflow tank on my Nova. It's kinda big and bulky, but works as intended.

Another benefit to a visible/translucent overflow coolant tank is that you can identify that you may a coolant leak by observing the normal coolant level within the overflow tank should this level begin to change/drop.

 

[Redrider66SS]

i saw an over flow tank made from a jack daniels 5th. bottle at a car show last summer. i don't think you want to try that though.

 

[onecarnut]

[QUOTE="Munky, post: 5869304, member: 136715"
Thinking about running a 1973 overflow tank or trying to find a smaller aluminum tank to mount down below the battery somehow. Has anyone ran something similar and have any recommendations?

I should note that my car is not overheating or running hot. Gets to the 180 (thermostat temp) and stays there until shutoff. Then it creeps up to around 200° before cooling off.
[/QUOTE]

I have had a few cars in the past that performed well without the radiator being filled to the brim.

Its almost as if each individual radiator would seek its own fluid level.

 

[Ray_McAvoy]

Thinking about running a 1973 overflow tank or trying to find a smaller aluminum tank to mount down below the battery somehow. Has anyone ran something similar and have any recommendations?

Like RifRaf, I'm also using the stock tank in my '74. Works good, but yes the 73-74 style tank is kind of big & bulky looking. For something a bit more hidden out of the way, you might want to consider a 76-79 Nova / X-body style tank. They tuck inside the front portion of the passenger side fender (beside the battery). Reproductions of the 76-79 style tank & cap are available and folks have retrofitted them into the earlier year cars (back to '68) without any trouble. Although, note that 76-79 originally had a protective plastic cover snapped onto the edge of the battery tray to prevent it from rubbing/wearing a hole in the tank. Something similar might have to be done in a retrofit, such as a piece of rubber hose slit down the side and slid over the edge of the battery tray.

 

[DaveT]

So the 1970 Nova did not come factory with a coolant overflow tank (from what I have read). I noticed that my radiator always balances out to have about 2-3 inches of low coolant when cool. If I fill the radiator completely and drive it then it will puke out a fair bit upon stopping and parking the car. It would seem that running on overflow tank would give the coolant somewhere to go and I assume be sucked back into the radiator to maintain a full system. Is that the correct assumption?

Thinking about running a 1973 overflow tank or trying to find a smaller aluminum tank to mount down below the battery somehow. Has anyone ran something similar and have any recommendations?

I should note that my car is not overheating or running hot. Gets to the 180 (thermostat temp) and stays there until shutoff. Then it creeps up to around 200° before cooling off.

On my 70 I installed a new brake pipe under the upper radiator core support over to the Windshield Washer Fluid Container. Went down to the parts store and picked up a straight piece of brake pipe, couple of clamps and some rubber hose. Not sure what size, maybe half-inch. I ran the pipe under the radiator core support and used the Windshield Washer Fluid Container as overflow collector. I haven't used the wipers in years so there was no need to buy another container. Get a vented radiator cap and do a little trimming. Works great and you can't really notice the difference in the engine bay. Leave the little hose on the inside of the fluid container on and it will work great.

 

[Munky]

On my 70 I installed a new brake pipe under the upper radiator core support over to the Windshield Washer Fluid Container. Went down to the parts store and picked up a straight piece of brake pipe, couple of clamps and some rubber hose. Not sure what size, maybe half-inch. I ran the pipe under the radiator core support and used the Windshield Washer Fluid Container as overflow collector. I haven't used the wipers in years so there was no need to buy another container. Get a vented radiator cap and do a little trimming. Works great and you can't really notice the difference in the engine bay. Leave the little hose on the inside of the fluid container on and it will work great.

I thought about doing this as my washer pump isn’t even connected currently. Ever have any issues with the bottle overflowing?


1970 Nova 350/4spd

 

[DaveT]

I thought about doing this as my washer pump isn’t even connected currently. Ever have any issues with the bottle overflowing?


1970 Nova 350/4spd

Haven't had one issue with it. When the engine gets hot the antifreeze does like any other vented system, it vents the excess up thru the cap over to the windshield washer bowel and then stores it until the engine cools down. Then sucks the liquid back into the radiator as it cools.
On mine, when the engine is cold the washer bowl doesn't have any liquid in it but when it's warm it shows about (I think) about 3 inch's from the bottom. I've been thinking about pouring a couple of inch's more in the bowl when it's cold just to show thats there always fluid in the bowl and radiator when it cold. Just like your newer cars always show cold and hot lines for fluid in their bowls.
On these radiators back then, you always left a inch or two of dead air space to adjust for expansion when the fluid heated up. Thats where you needed to burp the air out of the system (including the heater core and lines) came from.
With this, I can take the cap off when cold and the fluid level is close to top of the radiator but never has it overflowed out of the radiator.
I don't have any pictures of the washer bowl hooked up but you can get an idea how it starts out looking.
It's worth a try and if you don't like it you haven't lost much money.
Hope this helps.......
Dave

 

[Munky]

Haven't had one issue with it. When the engine gets hot the antifreeze does like any other vented system, it vents the excess up thru the cap over to the windshield washer bowel and then stores it until the engine cools down. Then sucks the liquid back into the radiator as it cools.
On mine, when the engine is cold the washer bowl doesn't have any liquid in it but when it's warm it shows about (I think) about 3 inch's from the bottom. I've been thinking about pouring a couple of inch's more in the bowl when it's cold just to show thats there always fluid in the bowl and radiator when it cold. Just like your newer cars always show cold and hot lines for fluid in their bowls.
On these radiators back then, you always left a inch or two of dead air space to adjust for expansion when the fluid heated up. Thats where you needed to burp the air out of the system (including the heater core and lines) came from.
With this, I can take the cap off when cold and the fluid level is close to top of the radiator but never has it overflowed out of the radiator.
I don't have any pictures of the washer bowl hooked up but you can get an idea how it starts out looking.
It's worth a try and if you don't like it you haven't lost much money.
Hope this helps.......
Dave

Awesome. I snagged some hose today and ran it to my washer bottle. Will test it out next weekend.


1970 Nova 350/4spd

 

[ProjectX]

I used a aluminum tank I picked up off of amazon years ago and it works great. It looks a lot better than the drag racing style round tank that was mounted up when I bought the car. Looks clean and I have it right beside the radiator mounted on the core support. Works like a champ.

https://www.amazon.com/SUPERFASTRACING-Radiator-Polished-Stainless-Universal/dp/B07TBQZBP4/ref=sr_1_53_sspa?keywords=radiator+overflow+tank+aluminum&qid=1579049555&sr=8-53-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzNDQyQlAwNVA0SFJMJmVuY3J5cHRlZElkPUEwMDk3NDIyM0NNUE1HWUQzSTM5VCZlbmNyeXB0ZWRBZElkPUEwNzE4MTc3M0VVV0ZRTDBIMDRCUCZ3aWRnZXROYW1lPXNwX2J0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

 

[Orion526]

I put a '73 tank in my '72. Posted a photo in this thread:
Radiator Overflow Bottle Help