8V92 Thermal Cycling, Weir Thermostat

[david brady]

Folks,



Have any of you two-stroke diesel owners tried a Weir

Thermostat?



I learned that the reason the S60 behaves the way it does;

that is, able to operate at any temp within it's t-stat operating


range in temperature equilibrium w/o the fan on high speed is

because of the Weir t-stat.



Basically the Weir t-stat starts to open a small amount and will

remain open a little if the cooling system temperature stays the

same. If the coolant gets a little hotter, then the Weir t-stat
opens

a little more in a very controlled manner. This makes for much

better coolant temperature control and fluid flow control. The

Weir t-stat came on the scene around 1997 and is in common

automotive and trucking use today.



The Weir provides just a fraction of the flow of a traditional
t-stat

at the same operating temperature. Traditional t-stats can cause

thermal cycling as the t-stats were basically open and close
devices.

This behavior lets a flood of cold coolant into the engine which
then

closes the t-stat. The engine then heats up, the fan kicks on, the


t-stat opens, and again a flood of cold coolant enters the engine


which closes the t-stat, and the cycle repeats.



Apparently the Weir t-stats are available for the early two-stroke


diesels and can be retrofitted.

__________________

David Brady

'02 LXi, NC