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Header Tank Position
the_big_1 - 8/10/20 at 07:22 AM

Hi Guys,

Guessing the rule of thumb with the header tank is that it should be the highest point to allow air to rise etc.
A part from the bulkhead, how have people located it so its still the highest point (If needed to be).
Locate at 2.0L Silvertop ideas etc.

Cheers!

Deckman001 - 8/10/20 at 07:31 AM

Hi,
I've not tried it as I don't have the type of system that could use it, but you might get away with using a pressure cap on the rad instead ? that way the rad could be the highest point, but remember that you need a decent filling point so bear that in mind.

Jason

the_big_1 - 8/10/20 at 07:33 AM

Yeah I thought that too but my rad hasn't got a filling point, I think its polo?

Deckman001 - 8/10/20 at 07:37 AM

So you'll need to make sure you have a header tank then at the highest point, no other options i think for a workable solution. If you have enough flexible pipework though, you might get away with a small header tank.

Jason

the_big_1 - 8/10/20 at 07:39 AM

hi,

Yeah thought that was the case. Where is the highest water level on the engine that the tank has to be higher than?

Deckman001 - 8/10/20 at 07:54 AM

quote:
Originally posted by the_big_1
hi,

Yeah thought that was the case. Where is the highest water level on the engine that the tank has to be higher than?


I'd assume that the rocker cover is just to be sure, and maybe even put a level across it towards the scuttle to ensure the cap is still the highest point. while the car is sat correctly and with normal weights all round if possible, otherwise your positioning might be a bit out.

Jason

the_big_1 - 8/10/20 at 07:57 AM

Hi ya,

Could only ever fit on bulkhead then lol

JAG - 8/10/20 at 08:13 AM

Water doesn't go any higher than the cylinder head - forget about the top of the rocker/camshaft cover. The top of the cylinder head is the bottom of the rocker/camshaft cover.

I mounted my expansion tank under the nose cone and it works very well

the_big_1 - 8/10/20 at 08:16 AM

is your head lower or level with the nose, not looked at mine to be honest lol

40inches - 8/10/20 at 08:27 AM

Header tank doesn't necessarily have to be the highest point.
Mine is 150mm below the heater and 50mm below the rad top and works fine
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the_big_1 - 8/10/20 at 08:31 AM

Hi,

I guess its ok on yours as the rad has a fill point etc?

the_big_1 - 8/10/20 at 08:32 AM

I guess the question is, if the rad fill point and header tank are lower than the top of cylinder head, how do we sort the air lock / bleed etc.

JAG - 8/10/20 at 01:27 PM

quote:

Header tank doesn't necessarily have to be the highest point


This ^ is true but the header tank SHOULD be the highest point to ensure the system can be bled and works as well as it should

the_big_1 - 8/10/20 at 03:10 PM

Only issue I have I think it the coolant pipe I have at the rear, a Neil Dunne one, has a small pipe outlet facing up so pipe would be slightly above the hight of the header tank. I guess a small inline bleed valve could be used?

Mr Whippy - 8/10/20 at 03:32 PM

bleed it on a hill

the_big_1 - 8/10/20 at 03:38 PM

lol true. There is a small bleed valve on a well known auction site, used on caterhams etc,

https://www.ebay.co.uk/itm/New-in-stock-Caterham-Westfield-kit-car-Bleed-Tee-Coolant-valve/292744817013?hash=item4428f36975:g:A3cAAOxyqUpQ8xmU

I Could fit it just above the outlet at the rear.