Thermostats

[graham.hilder@xxxxxxxxxxxxx (Graham Hilder)]

Thanks everyone who has posted recently on this topic.

It does seem clear that insufficient flow restriction (due to
thermostat missing) may cause either :
a.  General engine overheating (due to pump cavitation) 
          Or
b.  Localised overheating in crtical head areas (due to stagnation
in some specific head passages at excess general flow rates). 

In the first case your gauge might read higher than normal
(because the whole of the engine and coolant truly is too hot), 
but in the second case your gauge might read too low (because
most of the engine and coolant really are too cold, with only
isolated spots too hot).

It seems that the above effects and results would mainly show up
at high RPMs, and at that would explain why I would never have
encountered them...... any maltreated thermostatless bangers I
have purchased, I've fixed up and sorted out before giving them
any tastes of main jet and red line.    So I would only have
encountered my cold-running consequence of no thermostat,
occurring at low to moderate RPMs.  

Looks like we've got to the bottom of it all.
Best regards,
Graham H,
New Zealand.

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