[TR] Further Thoughts on Cooling

[John Macartney]

My two cents worth FWIW is as follows:

There was some concern at the factory many years ago about cooling issues generally. On the wet liner 4 cylinder engine, cooling could become a problem if 'crud' build-up started to accumulate and especially behind cyl no. 4 and this was particularly so when the engine was in a tractor. Farmers often topped up coolant from a pond or somesuch :)

On the in-line six, much concern was expressed about the 'siamesing' of cylinders three and four where there was no coolant passage but later use of the car in hot climates such as Africa, the Middle East and Australia seemed to make this concern ill-founded. 

Similarly, on the Spitfire and particularly when cyls 2 and 3 were offset from 1 and 4 (de-axe) though again ill-founded. However, there was much harsh comment when the Spitfire engine grew to 1500cc as (I feel fairly sure) the coolant passages only were only in front of number 1 and behind number 4 - so effectively the whole lot were siamesed together to keep the block to the same overall length.

All that said, cooling never seemed to be an 'issue' when operating in very hot climates. The secret is to ensure all coolant galleries are clear of obstruction throughout the system including radiator and heater matrix, the thermostat is fully operational as per spec and the water pump is in good condition and doing its job.

The only troublesome engine was the Stag V8 in which the wrong alloy was specified by Purchasing in contravention to the spec laid down by Engineering and also the casting itself was so complex that many engines still had lumps of casting sand and wires frames embedded in the block that refused to be extracted. When Joe Pawlak was rebuilding the engine in the car I drove across the States and Canada in 2009, he showed me all the foundry residue he finally extracted when the engine was rebuilt. As a result, 'uncle jack' never overheated once to any noticeable degree except twice. One was sitting in a queue on a stinking hot day at the Canadian frontier south of Montreal and once in traffic crawl around San Francisco. Switching on the heater was *all* I had to do to knock the temp gauge back to normal. In fact, although I checked coolant every day before start up, the only time I topped up was in Tallahassee a day after trip start with one paper cup of water - and I used no more for the next 18,000 miles!!!!!!!!!! Come to that, apart from oil changes at 6,000 mile intervals, I only used two pints of oil in the whole journey - and no leaks anywhere:)

Jonmac



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