Thread: Coolants for older engines

Originally Posted by Lotz-A-Landies

Demineralised water and a sacrificial anode and avoid glycol altogether. At least that is the advice from an aviation engineer used to maintaining old liquid coolant aero engines and WWII vehicles. Most series engines would fit into the same category of WWII vehicles.

Many WW2 aeroplane engines used a pure ethylene glycol coolant - but they were designed for this, taking advantage of the fact that the higher boiling point allowed a higher operating temperature, with advantages both in combustion and heat transfer. Pump capacity and coolant flow design would have taken account of the lower heat capacity.

John

Originally Posted by JDNSW

Many WW2 aeroplane engines used a pure ethylene glycol coolant - but they were designed for this, taking advantage of the fact that the higher boiling point allowed a higher operating temperature, with advantages both in combustion and heat transfer. Pump capacity and coolant flow design would have taken account of the lower heat capacity.

John

The problem is that glycol also damages the aluminium airframe when spilled on it and penetrates the pores in the aluminium engine parts as well.

Apparently glycol has also been removed from the de-icing fluid sprayed on aircraft in winter conditions.

Originally Posted by Lotz-A-Landies

Demineralised water and a sacrificial anode and avoid glycol altogether. At least that is the advice from an aviation engineer used to maintaining old liquid coolant aero engines and WWII vehicles. Most series engines would fit into the same category of WWII vehicles.

So Dianna,
do the alloy threaded (conduit) plugs in the series block suffice as the "sacrificial anode"?


Cheers, Mick.

Originally Posted by mick88

So Dianna,
do the alloy threaded (conduit) plugs in the series block suffice as the "sacrificial anode"?


Cheers, Mick.

judging by the condition of most i have seen, yep.

but they are a pita to replace

which is why i went to brass ones with a shoulder and use the block heater plug as the "sacrificial anode".

they are cheap, easily available from most hardware shops and easy to replace compared to the other suckers... and a spare doesnt take up much room under the middle seat

Originally Posted by JDNSW

One of my friends reckoned he drove his 34 ford round for several days with no headbolts to try and free the alloy heads, but I think he was exaggerating!


John

A friend in the UK did this with a Triumph Stag.....


Colin

Originally Posted by Lotz-A-Landies

Demineralised water and a sacrificial anode and avoid glycol altogether. At least that is the advice from an aviation engineer used to maintaining old liquid coolant aero engines and WWII vehicles. Most series engines would fit into the same category of WWII vehicles.

As there is an anti-corrosion package in glycol based coolant it shouldn't be a problem but it would mean changing coolant every few years.

Corrosion | Chemical Processing Expert Forum: What causes corrosion from ethylene glycol?

So is the sacrificial anode a better or just cheaper alternative (when you take labour into account and proper disposal of the used glycol mix) ?


Colin

A sacrificial anode is only of use in the case of electrolysis between dissimilar metals.
It would have no effect on corrosion due to acids or rusting.

Originally Posted by Lotz-A-Landies

The problem is that glycol also damages the aluminium airframe when spilled on it and penetrates the pores in the aluminium engine parts as well.

Apparently glycol has also been removed from the de-icing fluid sprayed on aircraft in winter conditions.

I think you may have been misinformed.