Ok, PCTECH whetted my appetite in Golden86's build thread by showing a tank that is put in line and "self purges".
//www.fiero.nl/forum/Forum2/HTML/068188.html
I sent him an IM, but I don't think he checks often and I'm in the middle of my swap and want to know what year it came out of and how it works. There are tons of aftermarket coolant tanks and I'm wondering if the fact that he mounted his at the highest point in the coolant loop allows the air to get out there, or if it's got some special feature.

I looked real quick in the thread but did not see the tank he is using?
This is the tank I put in. It is from a C4 Vette. 84-96






This is the same tank Mcaanda is using but he put his on the pass side and I put mine on the driver side.
I used a 20# cap on the radiator and plugged off the hose barb so it does not suck in air. Then used a 16# cap on the surge tank.

quote Originally posted by Rickady88GT: I looked real quick in the thread but did not see the tank he is using? This is the tank I put in. It is from a C4 Vette. 84-96 .

And this is because it was Mcaanda's car... brain fart .... I wonder who I sen the PM to; since I think I used the button on the thread post, I guess it went to Mcaanda. (I wonder where I got PCTECH ) Thanks for the info. Looks like yours is on a N*. What is your coolant routing?

I have the 3.5 V6 Short Star. My car is done differently than Mcaandas car. Mine was almost stock Intrigue. Mcaandas car was moded, and I don't exactly remember how he did it. But we did drill a hole in the water jacket of the intake manifold and tap it for a hose barb. But there are as many ways to do engine swaps as there are people doing them. You may do yours differently.

If I recall correctly, the one from the other thread was a C5 tank.

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It looks like the tank in this thread is being used as a surge tank, while Golden 86's is just being used as a fill point and "high spot" to burp the system.
I'm a bit confused.
How does this one work? Since the front is essentially capped off, it appears that any "overflow" is going to happen at this tank. But where does the fluid go if the system overflows, and how does it get back into the system.
(I know how the regular overflow bottle works. This one looks way different. Is it under then same pressure as the rest of the cooling system at all times?)

[This message has been edited by Raydar (edited 06-16-2006).]

Raydar

Yes the tank is under the same pressure as the engine coolant system.

Just FYI the 1 Gen. Dodge Intrepids also have a tank like this that could be used. It is a little taller so would probably would not fit on top of the battery like the vet one. But is an easy source for them in a salvage yard.

The yellow lines point to where the coolant lines connect.

[This message has been edited by Dodgerunner (edited 07-14-2006).]

this just looks like a re-located overflow tank?
while its not alot - I would rather keep the weight up front, and down low.
but, I suppose keeping it between the wheels is a +

quote Originally posted by Raydar: How does this one work? Since the front is essentially capped off, it appears that any "overflow" is going to happen at this tank. But where does the fluid go if the system overflows, and how does it get back into the system.

Unless my eyes are deceiving me, the surge tank pictured above has three hoses. The hose directly underneath the cap is likely the overflow, the next lower hose is probably the inlet, and if you look at the 3^rd photo there appears to be an outlet hose which hooks up to the bottom of the tank.

I assume that the overflow hose is either connected to a recovery tank which isn't shown, or is open to the atmosphere.

The difference in these tanks is that the coolant can flow through the tank since they have and in and out port as well as an overflow line so the air is left behind in the tank. Guess you could say it's a cheap air seperator.
The Intrepid has NO cap on the radiator.
A normal overflow tank the coolant just moves to and from the tank as it expands and contracts. If any air is not trapped under the radiator cap it will never move out of the system.

[This message has been edited by Dodgerunner (edited 06-16-2006).]

The Vette tank is a purge tank and has no need for a over flow tank. The radiator cap is on the Vette surge tank and not the radiator. That is why the Radiator has a 20# cap and a plugged hose barb on it. Theoretically the 16# cap on the Vette surge tank will purge and vent the cooling system, NOT the cap on the radiator. The surge tank is at the highest posable point in the engine bay and 100% of the air in the cooling system will eventually get trapped in it because it is at the highest point in the cooling system. That way you NEVER get air in the radiator or coolant tubes. There is no need to purge air out of the radiator because air cant go down hill thru the coolant tubes to get there. As long as you have a healthy cooling system you will never get air in the system, it all gets trapped in the surge tank. This is how all new cars are done. New cars do not vent at the radiator. They vent at the surge tank. The surge tank is made to handle the full coolant system pressure.

The Vette surge tank has 4 lines on it.
1) top line just under the radiator cap is a vent hose and goes to the ground like any other vent how on any other cooling system.

2) the hose just under that one is the in let hose and is supplied by the throttle body heater hose.

3) there are two hose under the tank for return lines. One goes to the return side of the thermostat and the other goes to the return coolant tube under the passenger side of the car.

I was looking for a under hood pic that shows the lack of a over flow tank but could not find a good one

[This message has been edited by Rickady88GT (edited 06-16-2006).]

quote Originally posted by Rickady88GT: The Vette tank is a purge tank and has no need for a over flow tank. The radiator cap is on the Vette surge tank and not the radiator. That is why the Radiator has a 20# cap and a plugged hose barb on it. Theoretically the 16# cap on the Vette surge tank will purge and vent the cooling system, NOT the cap on the radiator. The surge tank is at the highest posable point in the engine bay and 100% of the air in the cooling system will eventually get trapped in it because it is at the highest point in the cooling system. That way you NEVER get air in the radiator or coolant tubes. There is no need to purge air out of the radiator because air cant go down hill thru the coolant tubes to get there. As long as you have a healthy cooling system you will never get air in the system, it all gets trapped in the surge tank. This is how all new cars are done. New cars do not vent at the radiator. They vent at the surge tank. The surge tank is made to handle the full coolant system pressure. The Vette surge tank has 4 lines on it. 1) top line just under the radiator cap is a vent hose and goes to the ground like any other vent how on any other cooling system. 2) the hose just under that one is the in let hose and is supplied by the throttle body heater hose. 3) there are two hose under the tank for return lines. One goes to the return side of the thermostat and the other goes to the return coolant tube under the passenger side of the car.

Perfect!
Thank you sir. Much appreciated.
Thanks to Pyrthian, Dodgerunner and dguy as well.
This gives me some ideas.

[This message has been edited by Raydar (edited 06-16-2006).]

quote Originally posted by Raydar: Perfect! Thank you sir. Much appreciated. Thanks to Pyrthian, Dodgerunner and dguy as well. This gives me some ideas.

For the people that want to convert the stock Fiero system over to a surge tank system, you can use the stock Fiero throttle body heater lines and rout them to a surge tank instead of the throttle body.

Quick bump...

Rick, Do you happen to know the part number for the tank?
I looked on the web and all I could find was a drawing of an "overflow bottle" that looked similar to the one in the Fiero.
It also was way too cheap for what it is (but about right for the flimsy white plastic one.)

Thanks.

Edit - Nevermind. Eckler's has them (if I can't source a used one elsewhere.)
Found several different styles. Just need to figure out which one I want.
I've also got to figure out how I want to plumb it in to a 4.9 installation. No TB coolant lines. (Never thought that would be a bad thing. )
Think it would work "in series" with the heater hose that comes from the thermostat housing?
Or teed off from the heater hose? That would actually be much easier.

[This message has been edited by Raydar (edited 07-03-2006).]

Raydar -

I know on mine, it says: "GEIGER PLASTICS ..."

Here's a pic of it if you need for reference when making sure that you get the right one. I'd really suggest that you check yards, as Im sure that new they are really going to hit ya in the check book. I think that when I picked mine up, it was ~25.oo MAX. And thats in a CA where EVERYTHING is GOLD in "Mullet Dave's Pick and Pull."



--Allen

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** Rice; it's what's COOKIN **

Thanks Allen.

I'll check the yards, too.
Eckler's wants $69 for one. (Talk about "made out of gold" )

Found 'em.

www.corvettesalvage.com $75
www.justcorvettes.com $100

www.tabercorvetteparts.com $20

Guess which one I gave my business to?

quote Originally posted by Rickady88GT: For the people that want to convert the stock Fiero system over to a surge tank system, you can use the stock Fiero throttle body heater lines and rout them to a surge tank instead of the throttle body.

I very much want to convert over to this system, but for the verbally challenged, do you have a drawing of the routing of the tank? I'm having trouble visuallizing what it's supposed to look like. My reason for converting is to clean up the front compartment as well as making burping the system unneccessary. This is the way GM should have plumbed the Fiero.

Checking out this link it does show a coolant/recovery tank for anti-freeze. I want to hook up this tank to my 2.8 also, the vette tank does not let you see when the anti-freeze is low so I guess that tank shouild stay part of the system?? Sorry to be challenged by this topic but I want to get it right the first time.


http://www.madvet.com/shop?frame=1.138.935

RUNDLC

Would a possible good place to hook one up be the two lines that go for TB heat? I was going to leave the TB heat off on my 3.4 and was thinking about what I would plug the ports by the thermo with. Could just run them to one the these tanks.
Might not take the air out the fastest but there would be flow in and out from them.

[This message has been edited by Dodgerunner (edited 10-07-2006).]

quote Originally posted by RUNDLC: ... the vette tank does not let you see when the anti-freeze is low so I guess that tank shouild stay part of the system??... RUNDLC

There's a sensor in my tank for just that; it's a ON/OFF switched sensor. I never used it; but it's there.

Thanks Allen, I did see that, I wonder if that could somehow be tied into my lambo idiot lights?? OK gurus what would I need to make that happen?


Thanks RUNDLC

quote Originally posted by RUNDLC: Thanks Allen, I did see that, I wonder if that could somehow be tied into my lambo idiot lights?? OK gurus what would I need to make that happen? Thanks RUNDLC

Oh yea, it's a snap - you just have to figure out what the OEM switch does while the coolant is full. If there's no +12v when it's full, then you can use this for the wiring on your dash. Same is true if there's a +12v present at all times but missing a ground when full, but receives it when it's low.

Being that it's an "idiot light" Im "pretty sure" that it's not going to be a resistance switch - you want to know only when it's full vs low... If the above fails, check the resistance and see if it changes - there is the "unlikely" chance that it's going to set off a warning, and then a trouble light." You know how things get pretty fancy w/ Vette stuff.

I cant say for sure, but it shouldn’t be hard to find out. Grab your Multi-meter and fill it w/ some H2o and you've got what you need in ~5 min.

--Allen

You da man, you da man.

RUNDLC

The flow into the radiator is at the the top. The flow out is at the bottom. Even though the purge tank may be located higher than the radiator, it still seems like there would be a tendency for air or over noncondensibles to collect in the radiator.

OK, that diagram has got me confused due to what appears to be a U shaped tube that indicates that the bottom two ports are looped together.... this is the way I planned on doing the setup on my 3800 SC... please voice where the flaw in my logic may be.

quote Originally posted by jscott1: I very much want to convert over to this system, but for the verbally challenged, do you have a drawing of the routing of the tank? I'm having trouble visuallizing what it's supposed to look like. My reason for converting is to clean up the front compartment as well as making burping the system unneccessary. This is the way GM should have plumbed the Fiero.

I hate quoting myself, but I was just about to make this post, when I realized that I had already posted it...

Can someone make post a drawing showing where to tap the system? I have a hard time following written instructions.

quote Originally posted by slade1274: OK, that diagram has got me confused due to what appears to be a U shaped tube that indicates that the bottom two ports are looped together.... this is the way I planned on doing the setup on my 3800 SC... please voice where the flaw in my logic may be.

It does look confusing at first glance until you realise that the inlet comes from behind the tank, necessitating the U turn in the hose. it isn't connected back to the tank itself.

I have to dissagree with the notion that this (Vette) tank eliminates the need for an overflow tank. my Vette (92) had one.......... and therefor my N* Fiero has one as well. without an overflow tank there is nowhere for the hot (expanded) coolant to go, and to be recovered from later, when the engine cools.

.02
Russ544

Russ, do you think my routing looks like it makes sense? anyone else?

I agree, It does have an overflow tank, I'll install one on mine too.


RUNDLC

Russ, would you put an overflow tank fed by the vent of the surge tank or just have it up front in the stock location and keep the stock pressure cap up there?

quote Originally posted by cptsnoopy: Russ, would you put an overflow tank fed by the vent of the surge tank or just have it up front in the stock location and keep the stock pressure cap up there?

On mine I capped off the overflow at the radiator and built a small tank that sets down on the cradle below the surge tank. the surge tank is the high point in the system, and is where the air collects, so I felt that's where I wanted it to purge from.

Russ544

quote Originally posted by Russ544: On mine I capped off the overflow at the radiator and built a small tank that sets down on the cradle below the surge tank. the surge tank is the high point in the system, and is where the air collects, so I felt that's where I wanted it to purge from. Russ544

Any way you can take pics or put a diagram together?

quote Originally posted by slade1274: Any way you can take pics or put a diagram together?

I'll check this eve. my pics are on my home computer, so I'll see what I can dig up for you.

Russ544

Thanks Russ,

That makes sense.

quote Originally posted by slade1274: Any way you can take pics or put a diagram together?

Man I dug all over the place to find a pic of the overflow tank I made.... to no avail. I even tried to take a pic of it in the car. HA! that's a laugh as you can't even see it down there, much less take a picture of it. oh well, it's not that hard a system to explain I guess

here is a pic of the Vette surge tank:


The yellow hose at the neck of the tank goes down to a small tank that's sitting on a bracket on the cradel. this tank is just a large bikers water bottle that I fabricated a rigid inlet pipe that goes near to it's bottom. this allows air and excess water (hot) to go into the tank where the air leaves the system via a vent in the lid of this tank. when the engine cools the excess water is drawn back into the surge tank again through the same yellow hose. the rest of my system is much like the others who posted here earlier. the only diference in mine is that I collect and recover the water as it's heated and cooled (expanded and contracted).
hope this helps a bit.

Russ544

[This message has been edited by Russ544 (edited 10-10-2006).]

There is no "need" for an over flow tank/bottle. The Vette surge tank will work fine by itself. The vent hose at the top just vents to atmosphere. The overflow tank will allow your system to hold more water. The Vette surge tank is kind of shallow and at normal coolant level it does not hold a substantial amount of coolant, but has worked for me for a few years. The Olds Intrigue cooling system that I used as a model has no overflow tank after the surge tank so I did not put one on my Fiero/Vette surge tank. Just fill up the tank and it will purge out the extra coolant and run at its normal coolant level from then on.

That Vette schematic is CONFUSING. The highest hose barb on the tank is a system purge. That barb has a hose that "feeds" the overflow tank. That hose on my system just vents to atmosphere and I do not run the lower tank of the Vette system. Works fine without it, but no harm in running it.

It is important to note that IF you chose to use an overflow bottle you HAVE TO use the purge line from the SURGE TANK. You CAN NOT continue to use the stock Fiero overflow tank, because you can only have ONE cap purging and venting the system. If you have two caps purging and venting you will have some problems. That is why I used a 20# cap on the radiator and capped off the overflow barb on the radiator. All of the coolant purging and venting is done at the Vette surge tank.