Radiator Coolant

[UK6]

Hello fellow Bristol Enthusiasts.
I write to you seeking advice on what is the best coolant to run in my old 400 motor. I have just had some minor corrosion repairs effected to my cylinder head and I would like to keep my cooling system healthy.
At present I plan on running demineralised water with perhaps a cupfull of good old soluble oil courtesy of the liquid component of "Bar's Leaks" - I won't tip in the solids.

Are there any better options out there?
I am definately not going to run glycol mixtures.

Regards,

Brett B.

[ozy]

Hi Brett,

I would not use deionised water for three reasons, first due to cost, second due to necessity - it brings no value as the moment it circulates in engine block and radiator it is no longer deionised, and third, because it can do damage.

To explain the third point you need to understand what happens in the deionisation process - using an ion exchange resin, the metal cation contaminants are replaced with protons ( H+), which will have the corrosive effect of a weak acid hence causing the problems you wish to avoid.

If you live in a hard water area and are worried about dissolved hard water salts and cost doesn't matter then you need source DISTILLED water instead of deionised.

The Barrs leak is a good idea as a palliative treatment - after all it's been around for years and is very effective, I would bung the solid in as well as the liquid carrier. Using antifreeze is not a problem providing you use a glycol based product - some cheaper antifreezes use methanol as a freezing point depressor which can have the same effect as a weak acid - or deionised water. You can check this by rerading the CHIPS symbols and componenets listing on the side of the antifreeze bottle.

I would stick with using Bluecol combined with tap water/distilled water at recommended concentration for a temp min of -12 deg C .
Hoping this helps,

Ozy

[UK6]

RE RADIATOR FLUID

Thanks for your advice Ozy.
The distinction you make between deionised and distilled water is an
interesting point - I will run distilled water.
I am not convinced that I need to run glycol mixtures in the West and hence
I seek some advice on running a suitable inhibitor for our iron/alu engines.
Are there any other enthusiasts going down this track?

Further, would the addition of a recovery tank be a good idea to minimise
oxidation and retain the vital fluid? If so, I recall that the early Range
Rovers had a nice small brass overflow tank. Are there any other suitable
options for our period cars?

Yours in motoring,

Brett B.

[ozy]

Brett,

Using distilled water alone is not a good idea. Proprietary antifreezes use an inhibitor, thought to be a multi-dentate complex - I don't know what is used. You need that inhibitor to prevent the corrosion which is not due to atmosheric oxygen dissolved in the water as some believe. In the '50's the inhibitor was borax or a borate salt but performance was found poor in repressing electrochemical reactions once we started to see exotic alu heads on iron blocks.

An expansion tank is always a good idea, glancing through the classic motoring comics on a recent visit to Asda ( I'm too imporverished to buy them), I saw an ad for some great accesories, one of which was a nice and reasonably priced stainless steel header tank. Try Practical Classics to see if it's in the latest edition.

HTH

Ozy

[Kevin H]

If you want to stay original-ish, the V8 Bristols had an expansion tank, at least my 411 does anyway. It is a cylinder about 12" long and about 4" in diameter from memory, made of brass I suspect.

Regards,
Kevin

[Richard]

An expansion tank is always a good idea

What would be the advantage of fitting one to a 6 cyl car and has anyone done it?

Richard