Anti-Frezze expandtion thru overflow @ Shutdown

[Legal Bill]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

Ray and gra, thanks for taking the time to post such thoughtfula dn helpful answers. I just got a lead on an MG tank over in the MG forum. If I use the MG tank with a pressure cap, any thoughts on what the pressure should be for the radiator and the return tank caps? I figure the radiator cap pressure needs to be less that the return tank cap pressure. But I don't wantthe return tank cap to be so strong that it creates excess pressure in the radiator.

 

[RAC68]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

Hi Bill,

As I understand, under a pressurized system, the additional tank should be considered an extension of the radiator rather than a separate container and requires a pressure hose connection and cap to maintain originally-specified system pressure. The cap on the radiator need not be a pressure cap as the primary pressure cap is on the expansion tank.

As original, an area within the top tank functions as an expansion area and when hot coolant expands to exceed cap pressure and this space, it would escapes through the overflow. The function of a pressurized system is to move this expansion area out of the radiator to an external vessel and provide for more coolant within the radiator and a larger expansion area to help retain previously-lost fluid.

Under a non-pressurized recovery system, there is only 1 radiator cap and that is situated on the radiator. The recovery vessel is, as in modern cars, simply a plastic container that captures the overflow and presents it for vacuum recovery under cooling. The radiator is completely full as no expansion area is provided.

Requirements for tank placement under both approaches must be addressed. Under a pressurized system, the tank must be placed sufficiently high to provide a reasonably large air space above the level of the radiator neck and allow for coolant drain-down to completely fill the radiator. Since the tank and it’s connect are under radiator pressure, the tank can be located anywhere convenient.

Under a non-pressurized system, the recovery container must be placed sufficiently close to the radiator to allow the cooling vacuum’s retrieval of the expelled coolant.

Hope this helps.

Ray (64BJ8P1)

 

[tahoe healey]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

I have been following this thread for some time and at one time I considered an over flow reservoir too. I thought the MG brass one looekd "cool". Norman Nock said not to worry about it. Just use the proper cap. Once it does it's thing it will stop overflowing. That is exactly what happens. No over flow in nine years. If you are getting a bit of fluid spilling, there may be something else wrong.

 

[gra]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

I agree with Ray. Here is a link to a Steve Byers article that uses a midget tank in a pressurized system. I think it explains this alternative pretty well.

https://www.team.net/www/healey/tech/big_hly/cooling/coolantrecovery.html

George

 

[RAC68]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

Hi All,

After all that has been written and discussed, I have yet to see an advantage or unique benefit that a pressurized approach provides over a non-pressurized implementation other than the brass tank looks nicer than a plastic bottle. I appreciate this request may fall into a similar civil war as DOT 5 vs. Dot 3 but I recognize many have chosen to implement a pressurized system and would like to know why.

All the best,
Ray (64BJ8P1)

 

[Randy Forbes]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

The brass tank in my application is vented to atmosphere, or else the vacuum in the radiator couldn't siphon the coolant back into it.

What looks like a regular radiator cap on the recovery tank has actually been gutted, so that it only keeps the coolant from sloshing out; the lower, rubber seal is removed and the stainless steel upper seal was left intact.

 

[RAC68]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

Hi Randy,

Then, as I understanding, you have both a non-pressurized recovery system and the added bling of a brass container?

All the best,
Ray (64BJ8P1)

 

[Rob Glasgow]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

Found this old thread while looking for a method of installing a recovery tank. It answers most of my questions about how to install but I need some advice on where to mount the tank. I am thinking about making a bracket to mount the tank on the front of the passenger foot well and having the top accessible through the hole in the frame support. See the photos below.
Any thoughts on this location? It is out of the way and accessible but is it too low and too far from the radiator?

 

[RDKeysor]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

Moss sells a brass tube designed to block the bypass the port discussed earlier. This "blanking sleeve" is pricey at almost $15, part No. 434-135. It fulfills the function of the skirt on those very expensive skirted thermostats. I installed this bit and found no problem having a 160-degree thermostat nestles inside it. I have also fabricated a thin sheet aluminum surround around the top and sides of my recored radiator, making it in two pieces that join under the fan protection piece on the back of the radiator. It is secured at the top of each side by the radiator bolts. Rather than having to remove the bolts each time I want to remove this aluminum surround, I simply notched around the bolts. Tightening the bolts pinches the pieces (two about 3" wide on either side and joined at the top as described) firmly in place. I also notched the bottom of each side piece to mate over the frame member that runs directly behind the radiator. I have added another wrinkle picked up at the Tamp Bay area Brit car show, shimming the bottom of the radiator forward away from the earlier mentioned frame member. I used about 1" long pieces of electrical conduit held in place by the top radiator attachment bolts on each side. The idea is to allow more air flow between the bottom radiator tank and the frame member. This does require longer bolts at the bottom, and is hardly noticeable upon inspection. Does it work? Don't know because I also added other "fixes" in the process. Finally, getting back to the original discussion, I used a flat-sided Heinz ketchup bottle for my overflow tank, cable tying it to the right side (viewed from the driver's seat) of the radiator. I ran the overflow hose into it, and run that bottle about half full of coolant. Since I now live in Florida, I will never be able to do enough to keep my 3000 cool. I've done all of the heat shields (see Healey6) and insulating. Next, I am going to try Steve G's air-blocking panels on either side of the radiator and the panels under the shroud described in Healey6 and earlier in this discourse. We have had a beastly summer, but I have not seen 212 degrees on my temp gauge. I don't let the car idle unnecessarily, however. Also, I have bypassed my heater motor, telescoped the front and rear nominal 4" hoses, detached the hose at the heater, and directed that hose and its cool air (when underway) just above the package shelf above the passenger seat.

 

[steveg]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

Found this old thread while looking for a method of installing a recovery tank. It answers most of my questions about how to install but I need some advice on where to mount the tank. I am thinking about making a bracket to mount the tank on the front of the passenger foot well and having the top accessible through the hole in the frame support. See the photos below.
Any thoughts on this location? It is out of the way and accessible but is it too low and too far from the radiator?

I clamped mine to the shroud-support strut - not an option if there are horns there. More or less level with the top of the radiator.

PS - love the title of this thread. "Anti-frezze" sounds like an Italian dessert.:fat:

 

[jjs64bj8]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

Look at this thread post number 36. Look at the plastic tank I got from Advance auto parts for $10.00 and its placement. Works great thus far although I have not road tested the car yet. Just idling in the driveway and a couple of short trips around the block. When cold the tank is almost empty, when hot is almost 2/3rds full. As the car cools down the coolant is sucked back into the radiator. I did have the taller filler neck on my radiator replaced with the 3/4" one. This allows a little higher pressure cap to be used and a cap that has the proper seals to allow the above magic to occur.

Later in the same thread is a link to the plastic tank used.

https://www.britishcarforum.com/bcf...other-what-cooling-fan-is-this-question/page4

jjs64bj8

 

[Keoke]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

Just go to a good junk yard or a good local Volvo dealer and get a overflow tank for a P1800 Volvo and you will be good to go. It can easily be fitted to the right hand side of the radiator frame.

 

[steveg]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

I originally had a parts-store plastic tank similar to the above from Advance. It worked great. In fact it came with a rubber gasket in the cap which I cut down for the inside of the stock 7lb cap:

This is an unpressurized system - the radiator overflow tube runs to an outlet tube on the bottom of the tank. I'd keep the radiator full to the brim with the overflow tank 1/4 full.

Now am running the MG brass tank as Randy described but with a loose rad cap up top for appearances (I didn't gut mine). The setup is the same - overflow goes into the tank when running and gets sucked back into the rad when the engine cools.

Moss sells these MG brass tanks new for about $100 - pn: 459-690

 

[Rob Glasgow]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

I just finished installing a recovery system. Got the brass tank on ebay and few years ago and built a simple bracket to mount it to the bulkhead where the master cylinders mount for a right hand drive car. I was planning on installing it lower in the car but on the recommendation of the group, I kept it level with the main tank overflow. I made it un-pressurized by removing the small disk under the brass tank cap. Will be a while before I can really test it out.

 

[steveg]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

Rob,
You can leave off the hose from just under the cap as no coolant ever comes out there.

 

[Rob Glasgow]

Re: Anti-Frezze expandtion thru overflow @ Shutdown

Steve, Thanks for the suggestion. I certainly hope that is the case.