Running Temperature

[Colin Morgan]

It is interesting to see what others say about normal running temperatures.  The history of my Ruby and a date plate suggest that the radiator was last re-cored in 1957, so is no longer in its prime.  The core is the type with folded horizontal fins between vertical tubes (as shown in Fig 6, on p71 of the 'Companion').  I think this design is more efficient than the original?  The engine has always run on the hot side but has never boiled.  A few years ago I put a temporary thermocouple in the top of the radiator to see what temperature it was reaching and found it peaked at about 90 C on the typical runs I do around here - it is relatively flat.  Then, last week, as part of the investigation into air deflectors, I fitted the thermocouple again and found the engine was now running at up to 95 degrees on a warm summer evening.  So, whilst it is not boiling yet, the temperature is rising, and this seems a bit hot?  

[However, just remembered that I need to bear in mind that when an engine is running hot it is not always caused by poor cooling - it can be mechanical (binding brakes, low tyre pressures, etc), ignition (wrong timing, dirty plugs, etc), carburation (air leak on inlet side, etc), or poor compression, engine in need of decoking etc. If there is a boiling sound when the engine is first turned off, this suggests that the radiator was coping but there were pockets of localised boiling in the engine itself. Such an engine will probably smell hot.]

Colin

Update: Changed the radiator to another used one - now runs at 80 degrees maximum (with a 17 degree ambiant), which is more comfortable.