Header tank into bottom hose

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Twinturbotr7
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Header tank into bottom hose

Post by Twinturbotr7 » Mon Mar 11, 2019 10:27 pm

Hi when I read other posts on here most people say the best thing is to put the bigger connection at bottom of the header tank and tee it into the bottom hose why is this the best idea ? Surely any hot coolant that will be in the header tanks will go straight back into the engine,if it went back into the rad even halfway down it would help cool it down before being sucked into the engine ?



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stevieturbo
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Re: Header tank into bottom hose

Post by stevieturbo » Mon Mar 11, 2019 11:27 pm

If the cooling system is already full....how can this water flow en-mass into that system ?

It cannot. Water in there can only leave, as fast as it is replenished from somewhere else.
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Re: Header tank into bottom hose

Post by SuperV8 » Tue Mar 12, 2019 11:16 am

Header tank is only there to allow for coolant expansion and to collect air as the high point of the cooling system - there should be no meaningful coolant flow through it.

Tom.
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Twinturbotr7
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Re: Header tank into bottom hose

Post by Twinturbotr7 » Tue Mar 12, 2019 11:02 pm

Thanks for taking the time to answer me
, I thought there might have been more flow
In the header tank hence my thoughts on adding the coolent back to the rad

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Re: Header tank into bottom hose

Post by Twinturbotr7 » Tue Mar 12, 2019 11:03 pm

Thanks for taking the time to answer me
, I thought there might have been more flow
In the header tank hence my thoughts on adding the coolent back to the rad

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Re: Header tank into bottom hose

Post by stevieturbo » Sat Mar 16, 2019 1:07 pm

SuperV8 wrote:
Tue Mar 12, 2019 11:16 am
Header tank is only there to allow for coolant expansion and to collect air as the high point of the cooling system - there should be no meaningful coolant flow through it.

Tom.
There should be some "meaningful" flow through it. Headers are also a useful means of removing air from the system, which is usually the main purpose of the small pipe into the top of a header tank ( if one is being used...and many cases should be used if at all possible )
So the system essentially always self bleeds to remove any air from the main engine/rad. With as many bleed points as deemed necessary. If it runs this design and this vent/bleed into it gets blocked, it will have a negative effect on cooling operation. It doesnt need to move a lot, but it needs to move some air/water.
That's why on modern cars you'll always see the flow of coolant from this pipe into the header tank. Harder to see on older cars as the tanks are usually more discoloured etc and some very old cars dont run such a setup.

Although if it is just a sealed header tank for the purposes of filling and with a sealed cap and only an external overflow, on that setup there would be no actual flow as such.
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http://www.youtube.com/watch?v=XgWRCDtiTQ0

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Re: Header tank into bottom hose

Post by SuperV8 » Mon Mar 18, 2019 8:36 am

stevieturbo wrote:
Sat Mar 16, 2019 1:07 pm
SuperV8 wrote:
Tue Mar 12, 2019 11:16 am
Header tank is only there to allow for coolant expansion and to collect air as the high point of the cooling system - there should be no meaningful coolant flow through it.

Tom.
There should be some "meaningful" flow through it. Headers are also a useful means of removing air from the system, which is usually the main purpose of the small pipe into the top of a header tank ( if one is being used...and many cases should be used if at all possible )
So the system essentially always self bleeds to remove any air from the main engine/rad. With as many bleed points as deemed necessary. If it runs this design and this vent/bleed into it gets blocked, it will have a negative effect on cooling operation. It doesnt need to move a lot, but it needs to move some air/water.
That's why on modern cars you'll always see the flow of coolant from this pipe into the header tank. Harder to see on older cars as the tanks are usually more discoloured etc and some very old cars dont run such a setup.

Although if it is just a sealed header tank for the purposes of filling and with a sealed cap and only an external overflow, on that setup there would be no actual flow as such.
I think we have different understanding of the word 'meaningful'
I could have also written - there should be no significant coolant flow - either way I agree with what you wrote. There should be some small flow - otherwise I would have written - there should be no flow.
The only coolant flow through the header tank is to remove any air in the system.
Dax Rush 4.6 supercharged V8 MSII

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