Thermostat removal - possible issues

[Ivan141]

Here is just an interesting tidbit that me and Nohachi found on the inet. It is from a paper originally discussing another engine type, but the used logic should be more or less applicable to the 4A-GE (though, the 4A being a steel lump and the considered engine all aluminium, the 4A should hold up longer).

Quote:Removing the thermostat altogether, as currently practiced by some, is no solution, firstly because engine warm-up becomes protracted, with all the implications for premature engine wear and secondly, because the engine temperature is at the mercy of the pump speed, if engine speed falls, the coolant in the radiator will cool disproportionately, then as soon as engine speed builds and engine temperature with it, the pump speeds to sends a mass of very cold water from the radiator suddenly to the engine. There is no thermostat to even this process out so the engine is repeatedly subjected to thermal shock. Bad for the head, bad for the block, and sooner or later the gasket will go. Fit the thermostat to the coolant output and the extreme temperature gradients that beset the engine when used on the track are significantly mitigated. Modification of this coolant path is something that Lotus should have done with all the K series engines in all their Elise’s, This would have then prevented any gasket failures.