I have a 2000 SS. Does it come with a 180 thermo or a 195 thermo? I have done searches on LS1.com and Camaroz28.com and come up several different answers. One thing for sure there seems to be some mass confusion when it comes answering this question. Including this. http://www.fbody.com/members/stevenm...thermostat.htm

 

does it matter? add a fan switch and you'll run plenty cool. if not, put in an aftermarket thermo.


Ryan

 

Good question! Here's what I have gathered on the subject. I pulled the 'stats on the 3 engines I have in stock right now: 98 F-car LS1, 99 5.3L truck, and a 2001 F-car LS1. All 3 are stamped "86" on the copper insert which I believe is in Centigrade. This converts to roughly 186F. So yes, I think you can say you have basically a 185 thermostat. But the confusion starts here because ever since the LT1 engines the 'stat is located on the INPUT side of the water pump, NOT the return like good old Chevy engines were. I did most of the actual research on my LT1, but I think it applies to the LS1 the same way, since they both share 'stat location. My car would run in the 195 - 200 range under normal conditions. I pulled the thermostat and it said 180. I put in a 160 aftermarket 'stat and the temp dropped to 175 - 177 range. All temps were monitored with a Tech 2, not a gage. What I determined is that the 'stat opens at the specified temp, but this is on the input side of the engine. By the time the water gets thru the engine, it heats by approximately 15 degrees before exiting to the radiator. So in effect the engine is running at around the same temp as an old Chevy with a 195 thermostat. So unless the aftermarket thermostat makers (or modifiers) change the rating system of WHERE the temp is read, you can add about 15 degrees to the number on the stat box and you'll be pretty close to what the engine will actually operate at.
The fan turn on temp is a whole different story.

John
Speartech Fuel Injection Systems, Inc.
www.speartech.com