Cooling system silly question...

[chris.richard]

Does the header tank have to be the highest point in the system?

Does anybody use the high pressure caps (24PSI) as opposed to the 14 psi standard ones?

[chris.richard]

Originally posted by chris.richard
Does the header tank have to be the highest point in the system?



Still looking for answer on this one.

[David May]

The air is going to collect in the highest point, so if that's not the header tank, the only way you will get it out is with an auxiliary bleed valve there and the system under pressure.
It should not be hard to get the tank filler neck as the highest point?

Dave May

[chris.richard]

I'm lookimg at the options for siting the header tank. Sice I've moved the battery, I've space behind / under the AFM. I wasn't sure whether their position in cars is for convenience or physics!

Thanks;)

[Stratos]

Originally posted by chris.richard
Does anybody use the high pressure caps (24PSI) as opposed to the 14 psi standard ones?

Didn't know there was a high pressure version. Do you have a part number?

[rutthenut]

I use a high pressure radiator cap on my car, although that's more of a 'comfort feeling' than any particular need. I'm not sure it will make all that much difference but feel that it might just save it from boiling over some day.

Anyway, I got my cap from Demon Tweeks, page number 212 on the current catalogue. Sales hotline 01978 664468

Item 13: High Pressure Radiator Cap
22-24psi hexagonal cap (30136) £11.98 (plus VAT).

In my case, this is fitted to a modified Range Rover header tank, which is quite slimline and is of metal rather than plastic construction. Mod was to add a further water pipe connection.

[Stratos]

OK, I thought this was a high pressure screw-on cap to fit the standard 164 expansion tank.

I had a high pressure cap, like the Demon Tweeks one, on my car previously when I had the Volumex in it. But, then, I had a smaller metal expansion tank. (I think I still have the tank and cap somewhere)

When I upgraded to the V6, I also fitted the larger 164 expansion tank. With the amount of water we have in our cars, with the pipes running front to back, I would think the larger the expansion bottle the better.

[chris.richard]

I thought radiator caps were a universal fitting - or am I being naive?

Ther must be a way of working out the size of expansion tank needed; along the lines of:

volume required = total volume [hot] - total volume [cold]

we can measure TV[cold] , it's how much water we pour in.

TV[hot] = TV[cold] X expansion factor at 110 degrees

Anybody know what the expansion factor is?

[Andrew Way]

coef. of expansion for (pure) water is 21e-5 per °K, call it 2%.

but don't forget the volume of air.......

Andrew.

[Stratos]

Originally posted by chris.richard
I thought radiator caps were a universal fitting - or am I being naive?



Modern cars have a plastic screw-fit cap on the expansion bottle.

Older cars had the push-down and twist 90degress metal cap.

[Sando]

Hi
If you are in need a high pressure old type 90 degree twistdown Rad cap......

Try Halfords. Part number HRC 610 for most Peugeots ...£3!

20psi so should stop most kettles boiling over unless you have a serious problem.

cheers
Roberto:cool:

[Marmott]

I ve stayed with the standard 164 expansion tank , fitted to the transverse chassis rail , below the window, The level of the water should be above the engine to give reliable solution.
Tested this system over 8 years rallying in high temperatures and city traffic.
Interestingly ive found the best reliability by keeping the water level at the minimum line on the expansion bottle.

There should be no problems with the 164 installation using standard pump , antifreeze as normal, no wetting agent.
I do have a 4 core rad , and a Mini heater , all plumbed as standard