I searched and really didn't find much justification on either side. I ran one in my 3rd gen years ago and hated it but my tuner feels pretty strongly that a 160 is better. Why? Ability to put in more timing and less knock?

 

A lot of people tend to have big issues with those 160Tstats. I heard its a "engine killer".

 

oh boy..interesting im running one in my truck..

 

I don't know where the hell you heard that at. Geoff @ EPS actually gave me a bit of an *** chewing for NOT having one when I went and dyno'd.

Needless to say, there's one on my shelf waiting to go in when I get home.

 

A thermostat by itself won't do much unless you adjust the fan speed settings to take advantage of it.

The problem I had back in the day with a 160 stat on my Camaro was the car not getting up to a good operating temp on a cold day...if you only use the car in warm/hot weather, you'll likely never experience this, but it only took a brisk 40* day to make it readily apparent.

 

My short answer is "no".

I have three reasons for this.

The nerdy reason is that you radiator top tank temp(the temp at the top of the radiator before it begins getting cooled off) is the temp that matters when transferring heat to the air side. You can't do anything about air side temps, but the higher the rad top tank, the higher heat transfer will be. A 160 Tstat will not have as much heat transfer naturally as say, a 200. Additionally, most peple have their fans recalibrated to match, so now you fan comes on way earlier and more often to try and keep the engine below some target, I dont know, maybe 190 or 200. This just wastes fuelwhile driving around. Additionally, hotter coolant(within limits) around the cyl wall/head mean less heat is transfered from combusiton to coolant, which means more energy is available to make power. Finally on the nerdy side, hotter running engines have hotter running oil which is less viscous, so frictional(shear) and pumping forces are lower which equals yet again more power to the crank.

The second reason is that GM has clearly spent their engineering hours wisely on validation and testing. The engines ae validated for 100K miles despite our constant hammering on them. The piston/cyl wall geometry is directly affected by coolant temp(expansion of disimilar materials), and has proven reliable for normal coolant temps in the 210-220 range. If the temp is forced to be 20-30 degrees lower than that for thousands of hard miles, you can't expect to get the same reliability that GM did.

3rd,I'm sure tuners can get more timing in with less knock on a 160. I'd be interested to see a back to back example of the power gain for a well tuned 160 and a 200-210 thermostat. It would be very educational to see if the advanced timing outweighs the heat transfer, oil viscosity, etc... I guess I'd rather lose weight than force a couple more horsepowers.

On my LQ9 conversion(1969 442), I stayed with the stock thermostat as a tradeoff for a few HP for maintaining more durability.

 

160* is the way to go. Been running one for the past 7 years. You'll find the more power you make, the more you're gonna want to keep things cool. Heat is the enemy of all engines. One of the main reasons GM ran their engines so hot was for fuel economy, and since aluminum heads doesn't hold heat as much as iron, they can run higher coolant temps.

 

I had my car tuned once and afterwards the fans would never shut. I went back to the tuner and he said he thought I had put a 160 degree thermostat in so he tuned the fans to come for one. I went back and just gave me one for the "inconvenience". I installed it and I've had no issues for the few months I've had it (and my car's a daily driver too). My coolant temp has gone to 190 in traffic and that's the highest it has gone. On the interstate it will run at a constant 178 degree's. So far so good

 

One thing to think about. I have never heard of an engine failure due to being too cool (I am not talking about just plain cold), as opposed to being hot. When it comes to machinery heat is the enemy. Like stated above, the biggest reason for the hot temps is fuel economy.

 

I'd get a 180 tstat. Awhile back I remember reading a post on Corvette Forum from a guy who helped design the cooling system on the LS1 and he stated the motor was designed to operate best between 195-210* and similar oil temps.

 

No. Your stock cooling system will not satisfy the
'stat under low speed, hot weather conditions, so
you end up not improving anything where it counts.
But you will make the motor less efficient without
gaining any power at all, if that sounds like fun to
you.

Things to fix before even considering this piece of
old school "lore" are cleaning the condenser and
radiator, setting fans to just below (FAN1) and
just above (FAN2) the existing 'stat crack-point
(184F), upgrading the radiator to the thicker LT1
or better if you have a cash surplus.

Consistency is what you want, to tune against.
Adding a low temp 'stat without supplying it
even-lower-temp water is going to increase
coolant temp -inconsistency- meaning you
leae performance on the table to acommodate
the worst case hot, yet suffer low temp MPG
losses all the time - so just a way for clowns
who read and believe Car Craft magazine to
waste their money.

 

This^ Yet even on reasonably warm days it still takes longer for the car to get up to operating temp. And as jimmyblue says, once it's good and hot, the fact that it was slower getting there really doesn't make for a hill of beans.

My buddy's car has one and it never gets fully to operating temp on a really cool day. My M6 car must have one also, as it behaves the same way, so I just don't drive it on cold days. I much prefer the operation of the stock stat.

 

Brilliant! ^

From what I've heard, there is no worthwhile gain in adding a 160* stat to your car, only the possibility of giving your car issues it otherwise would not have faced.

 

My car has never had a problem warming up on a COLD days (Low 20's*). Folks are right about the fact that the 160* stat by itself will make no difference unless you've tuned the fans to come on earlier. If the motor is basiclly stock, leave the T-stat alone. If you plan on making a good amount of power, the lower t-stat will aid in warding off detenation which will kill and engine fast.

 

The hotter the coolant without boiling, the better for multiple reasons stated above, plus for the fact that it promotes complete combustion.

The legend or lore of a cooler t-stat was from the iron head/iron block days when a motor would overheat, boiling the water, which causes steam pockets, which then are hot spots inside the combustion chambers which are then a source of detonation or pre-ignition.

For the record, you want cool, dense air, and a hot, even temperature motor for best power, and a complete combustion process. Hot spots, or uneven temps are bad.

 

This is very true, but heat only becomes an enemy when it gets extreme (>230*). Engines live plenty good lives at a coolant temp below 230*.

So if heat is the enemy, then the idea is to keep the temps below 220*. A stock thermostat with adjusted fans keeps my engine at 196*-206* even in the hottest days. That is plenty cool enough for keeping the engine safe against its mortal enemy heat.

Going lower than 190* temps is purely for power, not for saving the engine vs. one that runs 200* coolant temps. I'd really like to see some evidence as to how much longer an engine will last at 170* vs. 200*.

170* vs. 240* is a huge difference in reliability, 170* vs. 200* I really really really doubt it makes a difference.

 

My argument was soley based on keeping things cool for power purposes. What alot of you fail to realize is how hot the coolant will get under WOT. I not argueing about engine life for daily driving, but if you want go there, I can say with my own experience that when I use to daily drive my car with a 160* stat, I never had an issue. I've noticed theres alot of theory in this thread and not alot of practicality.

 

But at WOT, there's a lot more riding on the cooling system's efficiency and performance rather than purely on the temperature that the thermostat opens.

An engine with stock cooling system and an 160* thermostat is going to run a helluva lot hotter at extened periods of WOT than an engine with a super dooper high quality cooling system and an 186* thermostat.

An 160* thermostat only allows the coolant to circulate into the radiator sooner, thus theroretically allowing cooler temps. But once you go WOT and temps start raising, it doesn't matter if you have a 160* or 186* thermostat...the coolant temps will be controlled by the efficiency of the cooling system.

So if you want to save your engine from heat at WOT, get a high quality complete cooling system. A measily 160* thermostat is not going to save a hi-po engine from heat if the rest of the system is not meant to handle all that heat.

 

Something else to consider, is oil temperature. You want the oil temp to get above 210 but stay below 240-250. If it doesn't get above 210, the oil will not burn off the accumulated moisture, which is bad for the oil life and bad for the bearings etc.

Just something to think about.

 

had mine for over 3yrs now........not a single problem.......hot OR cold weather