Ken, you are right. I just checked mine in the parts bin and there is no overflow port- guess my old memory isn't what it used to be!
Coolant Tank
- Thread starter Dan carter
- Start date
Ken, you are right. I just checked mine in the parts bin and there is no overflow port- guess my old memory isn't what it used to be!
Ken Roberts
Supporter
Here are some pictures to help explain. I chose the Moroso tank with the billet cap fitting. My finger is pointing to the overflow hose barb. On either side of the cap are the vent lines. The left one connects to the top of the radiator and the right one connects to the LS engine steam vent fittings. These lines should connect near the top of the coolant tank. You want them in the air pocket inside. Connecting them near the bottom of the tank (in the coolant) is frowned upon due to the fact the trapped air must push through the fluid before reaching the highest point the system. The path of lest resistance is near the top of the tank in the air pocket. Keeping in mind that the tank is only filled with coolant half way.
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Ken Roberts
Supporter
This picture is showing the Moroso overflow tank. The barb at the top connects to the main tank barb.
Ken Roberts
Supporter
Looking down at the top of the tank two observations are made. At the 9 o'clock position you can see a small hole at the left side. This is to vent the canister to atmosphere. The second observation is to look down at where the hose barb threads in. You can see a tube that travels down to the bottom of the tank.
As Scott pointed out in his post the canister must be vented to atmosphere and the hose barb must have a tube that travels close to the bottom of the tank. The canister must have coolant in the bottom to cover the pick up point or the coolant will not be able to be sucked back up the tube and travel back to the main coolant tank. It is a matter of physics.
If you are wondering about the two other indentations in the top of the canister at the 6 o'clock and 12 o'clock position) they are for the tool that was used to assemble the canister sections together.
As Scott pointed out in his post the canister must be vented to atmosphere and the hose barb must have a tube that travels close to the bottom of the tank. The canister must have coolant in the bottom to cover the pick up point or the coolant will not be able to be sucked back up the tube and travel back to the main coolant tank. It is a matter of physics.
If you are wondering about the two other indentations in the top of the canister at the 6 o'clock and 12 o'clock position) they are for the tool that was used to assemble the canister sections together.
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Ken Roberts
Supporter
Be aware of much cheaper overflow tanks that are just simply puke tanks. They do not have a internal tube for recovery of the coolant. They just dump the lost fluid in the tank. A petcock is usually installed at the bottom to later drain out the lost coolant.
They are still legal to use for drag and road racing.
They are still legal to use for drag and road racing.
i just run the puke line from the top of the remote fill tank to the bottom of an empty puke tank ... never had any issues with that and my puke tank is always empty. I've heard all sorts of stuff - run the line to the top of the puke tank, keep the puke tank half-full, etc... etc..., but that's what's seemed to work well across 4 builds for me.
Ken Roberts
Supporter
Running the line to the bottom of the puke tank is the same approach thus eliminating the need for the internal tube. For ease of installation the top entry point seems to be the most popular. You should always maintain a slight bit of fluid in the bottom of the puke tank. (just to make the physics happy)
Ya, always run some fluid in the puke/overflow tank. Without a benchmark known height, you will not know if you have an internal/hose leak somewhere until you are overheating on your gauge. Might happen close to home, might happen on a road trip.
I used a semiclear plastic tank for just this reason. Open hood, look at level in tank, and I know current status of my entire cooling system. Simple quick visual inspection.
I am using little motorcycle fluid reservoirs that are plastic for the fill point on my intercooler water circuit. One quick view of the level, and it tells me if there is a leak or not.
I used a semiclear plastic tank for just this reason. Open hood, look at level in tank, and I know current status of my entire cooling system. Simple quick visual inspection.
I am using little motorcycle fluid reservoirs that are plastic for the fill point on my intercooler water circuit. One quick view of the level, and it tells me if there is a leak or not.
Ken Roberts
Supporter
The Moroso round tank and the Canton rectangular tank are the 2 most popular choices. I personally preferred the Moroso due to its 3 leg mounting versus the Canton 2 leg mount. It was the more robust mounting option when making standoffs as shown in my #22 post.
Here is a link to the two tanks I have in use.
http://www.summitracing.com/int/parts/mor-63651/overview/
http://www.summitracing.com/int/parts/mor-85505/overview/
Here is a link to the two tanks I have in use.
http://www.summitracing.com/int/parts/mor-63651/overview/
http://www.summitracing.com/int/parts/mor-85505/overview/
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Ken Roberts
Supporter
Yup....3 7/8" to be exact. The rad cap isn't under the overhang of the spider now. Ideal for filling.
Gents
In review of my C6 Corvette cooling system (pic 1, heater connection is simplified), I note that a line from the surge tank is attached to the radiator and the steam port from my LS2. I also note from the build manual a similar setup (pic 2).
The RCR provided radiator has two petcock valves but no place to connect a line from the surge tank like both the Corvette and build manual drawings. Also the Corvette does not have an overflow bottle but simply dumps any lost fluid overboard. Since I am not going to race this car, compliance with a sanctioning body is not an issue, so I will use one of the RCR provided surge tank ports as the overflow port without a pickup bottle (for now anyway). I presume that the RCR tank has a pickup built in to allow for expansion/contraction of fluids (But not sure which port).
The question now remains, where will the second small port on the surge tank be connected? Is it only to the engine steam port, by passing a connection to the radiator?
In review of my C6 Corvette cooling system (pic 1, heater connection is simplified), I note that a line from the surge tank is attached to the radiator and the steam port from my LS2. I also note from the build manual a similar setup (pic 2).
The RCR provided radiator has two petcock valves but no place to connect a line from the surge tank like both the Corvette and build manual drawings. Also the Corvette does not have an overflow bottle but simply dumps any lost fluid overboard. Since I am not going to race this car, compliance with a sanctioning body is not an issue, so I will use one of the RCR provided surge tank ports as the overflow port without a pickup bottle (for now anyway). I presume that the RCR tank has a pickup built in to allow for expansion/contraction of fluids (But not sure which port).
The question now remains, where will the second small port on the surge tank be connected? Is it only to the engine steam port, by passing a connection to the radiator?
Attachments
Ken Roberts
Supporter
The stock Dorman tank has two hose barbs at the top. One is for the radiator and the other for the engine steam ports as Pete said. You cannot use one of them as an outlet for an overflow tank. The reason being as the overflow tank is open to atmosphere. If you connect it as you describe your coolant system will not be pressurized.
An overflow must be connected at the rad cap area. The hose barb would attach at the neck of the cap mount (after the cap seal). This is not possible with the plastic Dorman tank.
What confuses me is that you see lots of Corvettes at track racing events and drag strips. How do they pass tech when the coolant is just allowed to dump to the ground?
An overflow must be connected at the rad cap area. The hose barb would attach at the neck of the cap mount (after the cap seal). This is not possible with the plastic Dorman tank.
What confuses me is that you see lots of Corvettes at track racing events and drag strips. How do they pass tech when the coolant is just allowed to dump to the ground?
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Ken
I have tracked my vette for a long time and have never been called out on the vent issue.
So based on pete's mod, using the supplied surge tank, the system is completely closed with no overflow and under constant pressure. The Dorman is set for 16 PSI and would boil over the cap if it got too hot.
The Dorman tank would need to be changed out to include an overflow tank....correct?
I have tracked my vette for a long time and have never been called out on the vent issue.
So based on pete's mod, using the supplied surge tank, the system is completely closed with no overflow and under constant pressure. The Dorman is set for 16 PSI and would boil over the cap if it got too hot.
The Dorman tank would need to be changed out to include an overflow tank....correct?
Ken Roberts
Supporter
Yes if you wanted to capture any fluid that escaped. The Dorman tank has no provisions for that.
Does the Corvette have a pressure cap at the top of the rad? If so than your corvette surge tank is actually a overflow tank.
Does the Corvette have a pressure cap at the top of the rad? If so than your corvette surge tank is actually a overflow tank.
Ken
No cap on the radiator. It's on the surge tank
No cap on the radiator. It's on the surge tank
What size / type tubing are you guys using for the steam vent lines to/from engine and radiator? Did anyone use aluminum tube for the long run from the rad to the expansion tank?
Ken Roberts
Supporter
I used Teflon lined Aeroquip hose (1/4").
For my next car I will use a roll of 1/4" stainless tubing from Summit Racing. (for the rad to coolant tank)
For my next car I will use a roll of 1/4" stainless tubing from Summit Racing. (for the rad to coolant tank)
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Ken
Did you adapt the high side petcock valve to connect to the overflow tank like Pete did? Is there another way to connect the surge tank back into the radiator, or is it even necessary? Will fluid get sucked back into the system via the engine vent tube
Not sure why this radiator does not accommodate a surge tank directly.
Did you adapt the high side petcock valve to connect to the overflow tank like Pete did? Is there another way to connect the surge tank back into the radiator, or is it even necessary? Will fluid get sucked back into the system via the engine vent tube
Not sure why this radiator does not accommodate a surge tank directly.
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