Converting you stock Thermostat for lower temps

Instead of paying some vendor to charge you $80 for a LSX thermostat that is 178 or 160 degrees, modify the stock one for just a few dollars, plus control what that opening temperature is.  You can always change the opening rate at anytime, so your stock unit becomes adjustable.

The custom stat I purchased for a total of $80 with shipping is 178 degrees. I installed it and found during highway driving the water temps never got over 163 degrees !

I contacted the vendor to find that since I am using a good race radiator and hence it transfers heat out better then a stock radiator does and thus this $80 custom stat was too cold,

The stock stat pops apart by compressing down and turning to unlatching the part from the housing.

Once the parts are out, notice the shaft on stat sits in a hollow hole in housing.

By placing a shim of certain thickness will dictate when stat opens sooner.

                                     Overpriced Custom stat                                   Stock taken apart

These homemade shims ( thanks to teammate Gary S for his first hand experience and making the shims for my tests) as shown are .077, .101 and .125 thick.

Each would change when stat begins to open, As spring heats up, stat moves downward the shaft on back side.

The shim dictates how much travel the stat has on that shaft.

Simply place a shim into shaft hole in housing

As stock the shaft is barely seen in its housing

With shim is in, shaft sits higher.


A shim of .101 would reduce the stock stat from 194 degrees to 180 degrees. The thicker the shim is, the lower the stat temp rating is.





Return to Main Page

1990-2001 All Rights Reserved To join Free Contact : Team ZR-1