I see a lot of posts about using a cooler thermostat. My '86 L98 currently runs around 200-215 in normal traffic and a few degrees cooler on the Interstate. What are the advantages/disadvantages of installing a 160 degree unit? Educate me oh wise ones.

 

The engine operating temperature is NOT totally dependant on the opening temperature of the thermostat !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!
First, your 86 with a stock 195 stat should operate at 195 when you are driving over 35 mph. If not, then your radiator has debris picked up from the road in it which blocks airflow. One easy thing you can do is to use a garden hose set to its smallest diameter stream and blast water backwards through the radiator. Best is to remove the radiator and clean out the junk!! The search function will show you pictures of blocked radiators.
C4's have radiators sized to get rid of heat fast enough to maintain 180-195 F over 35 mph. GM is not talking, but we believe 195 was selected for emissions and 195 (and even your 200-215) is a perfectly safe temp to operate engines at. In the wintertime, the radiator has much higher capacity to get rid of heat and it is possible to maintain 160 F operating temp with a 160 stat, but this is too low a temp to operate an engine and you will have low heat available for cockpit heat.
In the summer, a 160 stat will be wide open and the engine temp will stabilize where the radiator gets rid of heat as fast as the engine makes it, and this is around 200 F, so installing a 160 F stat is a waste of effort and money.
The main fan comes on at 228F and the auxilliary fan (if you have one) comes on at 238F, and GM says to shut the engine off at 260F and let the engine cool down. Most of us have owned cars with 180 F stats and large radiators and have never seen anything over 180 F (like every one of my previous Corvettes) and when we see 200+ temps, we naturally get worried because our previous cars would boil over at these temps. My advice is to keep the 195 stat you currently have, clean your radiator out, and only become concerned when your coolant temp gets to 260 F.

 

Weren't you just telling us all in another topic how horrible mods are and how they make you car completely unreliable?



BTW: 215 is nice and cool for an L98. I wouldn't bother unless you plan to mod it out and just need the cooler temps.

The normal operating temps for an L98 is usually 210-220ish for most of us.

I have a 160 in mine, but I prefer the cooler temps, it helps from all the extra heat down here in FL. Any busy intersection in the summer can have ground temps of 115, which your car is sucking in while sitting in traffic, not including however hot the temps are from the cars around you that are also generating heat. Every bit helps for the hotter climate down here.


I wouldn't bother. if you start getting into the 230-240 range, then you have other issues that need to be addressed.

 

All the thermostat does is manage the warm up time and the minimal operating temp.

I agree with the above.

 

I have been wondering about going to a cooler thermostat on my C5. I emailed an auto engineer friend to get his opinion. He worked for Chevrolet (Corvette) and ended up as production manager (I think) for Viper and Prowler. He gave me some good advice that I always try to remember....

The automakers spend lots of money on engineers and testing on their cars.

With that you have to remember that the automakers also want to build cars to last (at least until they get out of warranty) so there is some room to increase performance. They also have to build cars to meet emmissions standards.

My friend John told me that the higher engine temps help with combustion. His advice was not to mess with the thermostat on my C5. I will track it a couple of times at the most and probably run 2 open road races a year.

If I was going to make a serious track car then I'd probably do something different. Just my $0.02.

 

Why would you want to mess with perfect operating temps like that. A cooler thermostat will give you one thing. Longer warm up times, or if the drive isn't long enough, incomplete warm ups. Either of these increase the wear and tear on the engine. A cooler opening thermostat won't change your warmed up operating temp. Just think for a moment, how a thermostat works and what it does. If your engine starts to run too hot, consider doing some maintenance.

RACE ON!!!

 

I wouldn't consider a cooler Thermstat a 'mod'. That's like saying different weight oils are mods. Thanks for the info folks, 'preciate it.