The design of the K series is poor on several counts.
1) the K series is designed to run hotter than most engines.
2) the poor design of the cooling system includes "hot spots" which cause cavitation - ie superheated water with no cooling.
3) the poor design of the feedback circuitry ends up with monitoring the water temperature coming back from the radiator, rather than the maximimum water temperature. Usually found leaving the engine.
See the threads in the QFAC section which cover it in considerable detail.
Hi TMHM
I would not go as far as 'superheated ' water lol
- also 'cavitation' is highly unlikely unless there is a considerable pressure drop between two areas of flow. - localised high temperature heating is possible -completely different thing altogether. ie, the localised 'hot spot' causes a sudden temp increase leading to boiling - which the causes a vicious circle - so here - the 'hot spot' is the cause of the localised issue - it is not 'caused by' a flow problem directly. it is simply exacerbated by any potential flow problem.
The engine temp differences to 'most other engines' is surely of no consequence in reality - or indeed - the position of the temperature monitoring.
These issues that you mention may have some basis for speculation and indeed some will have real credence, however the system would not run perfectly well for considerable periods of time between 'failures' without major design problems that are simply - live with - or get rid of. (as seems to be the case)
Again - are you saying that the HG failure causes the fluid boil off - or that the fluid boil off causes the HGF ?
Adding a substitute for water would make no difference if the thermal transfer is poor. - If the thermal transfer was as good as water then some issues may be alleviated.
I do not believe there is anything on the market that will perform as well as the heat transfer of water.
Many of the problems with the K series appear to be that after a HGF the correct remedial action is not taken (probably understandably
- by the repairer. for example block face checking and cylinder head face checking. As Tony says, the lack of thermal transfer ability of these so called replacement fluids would certainly lead to a rapid rise in the temperature of the fluid above its working temps and also if the so called 'hot spots' are causing localised temp increases (certainly NOT superheated) then it is likely, in fact almost certain, that the same thing would occur on these 'super fluids' as well - ie, a failure to adequately cool those areas due to an extremely poor thermal transfer - in fact it is likely to still occur.
Increasing pressure on the system and removing the failure problem of the expansion system on these engines is simple - fit a sturdier - preferably metal expansion / filler units and a higher pressure cap - this does not cause the engine to 'run hotter' it causes the water temperature boiling point to increase which is what you are trying to achieve with any 'super fluid' - again, water at higher pressure is a far better medium than a liquid with a higher boiling point but far lower thermal efficiency.
Joe