Water Level In header

[Stagmatt254]

Hi,

I have a neat Mercedes Benz header tank that I want to mount to the wing (similar to Grampian stags excellent example). Am I right in thinking that the water level in this new header tank would need to sit above the level of the top hose because: if the top hose is higher does the water level simply balance out (u tube manometer concept) and leave the top hose high and dry or am I missing the point.

Any sensible thoughts would be welcome.

[v8ken]

I was a gas engineer for nearly 30 years, and in my opinion any header tank should be at the highest part of the system, it also makes filling and bleeding easier.
I fitted one to the Stag lhs turret(not a 50 gallon one)but one from a rover 75,and it is the highest point of the system and works really well.
Ken.

[Guest]

I have a Merc header tank fitted to the bulk head, float switch wired to the seatbelt light on the dash which now reads coolant low

[Stagmatt254]

Thanks for the replies you seem to be confirming my thoughts.

[V Mad]

Coolant like any liquid will flow from a higher level to a lower level unless impeded by something. So long as the level of coolant in your header tank is not below the top level in the hose your hose should stay full.

[Stagmatt254]

Thanks chris. Seems to me that it is tricky to gain much more head without mounting the tank so that it hits the bonnet. I reckon I can gain about 2.5 inches above the top hose max.

[tonypy1]

Not the clearest photo but here's one of my Merc tank, which may be of use.

[tonypy1]

IMG_1428.jpg

[V Mad]

Thanks chris. Seems to me that it is tricky to gain much more head without mounting the tank so that it hits the bonnet. I reckon I can gain about 2.5 inches above the top hose max.

Yes but why do you need more head? You could put it on a pole 10 ft above the car, but it would be no better, and a bit tricky to top up.

[Stagsongas]

The thinking behind getting greater 'head' probably goes like this;

The higher the tank is in relation to the top of the top hose, the more of the tank contents would be made available to replace any coolant lost by the system. The limit is (depending on how high the tank is) the total content of that tank.

If the system is losing coolant, all that a greater 'head' will do (with the same tank volume) is to put off the evil moment for a few minutes or even seconds longer. I think a low level warning light or buzzer has more value - if you are losing coolant, you may as well find out sooner rather than later.

When installing my tank, I didn't think increased head was worth chasing too hard, and I didn't really want the tank contents being heated by the rising heat from the manifold.

Just my take on it.

Regards

Steve

[V Mad]

Well put steve. I would add that so long as the warning goes off before the level gets too low, it is doing a good job.

[pagan]

When installing my tank, I didn't think increased head was worth chasing too hard, and I didn't really want the tank contents being heated by the rising heat from the manifold.

Regards

Steve

So all is needed is the fluid level is the header, to be the highest point?

Allan

[steve.n]

In an ideal world above the top of the rad is where a header should be, I have gone for a lower point (stagwebber) but plumbed to the bottom of the rad. As said a warning is the critical issue to me, simple buzzer at the fuse box was my choice as the warning light is not so clear in daylight. As always other opinions are always valued. Steve.

[Stagsongas]

In an ideal world above the top of the rad is where a header should be, I have gone for a lower point (stagwebber) but plumbed to the bottom of the rad. As said a warning is the critical issue to me, simple buzzer at the fuse box was my choice as the warning light is not so clear in daylight. As always other opinions are always valued. Steve.

All agreed, save that on my car there is a good portion of the top hose at a higher location than the top of the Rad.

If you want to keep your top hose full, the upper level of the coolant in the tank must be level with, or higher than that point in the top hose. It does not matter where the tank supply enters the system, the levels will only equalise wherever the entry point is, but certainly, for other reasons, the lower it is, the better.

Good Luck

Steve

[Guest]

I have a question, me me me. I'm thinking of fitting stagdads external water pump in the new year, my Merc header tank is plumbed into the water pump cover at present, Steve points out that this won't be possible with his pump due to positive pressure. Now, I don't really want to go hacking at my radiator to fit a new connection so is it possible to maybe use one of the drain plug connections on the block? Or is this positive pressure too! My modern car has its header tank feeding the engine block!

Jason

yes, I know this question has been asked approximately 221 times!