160 degree thermostat and appropriate PCM flash

What are the advantages of a 160 degree thermostat with respect to a daily driver that is never driven hard?

What are the disadvantages?

Does it matter if a cold climate is involved?

Thanks,

Zero advantages (based on your usage).

Disadvantages: poorer fuel economy, higher emissions, faster engine wear, less heat output in winter.

jayoldschool wrote:

Zero advantages (based on your usage).

Disadvantages: poorer fuel economy, higher emissions, faster engine wear, less heat output in winter.

Just curious, why faster engine wear?

Chris

^^^Truth^^^ But thanks anyway....

YachtDriver wrote:

brokecello wrote:

Just curious, why faster engine wear?

Chris

[You must be registered and logged in to see this link.]

Wow...thanks.    Basically I've run a 160 stat on all Bbodies (one of the first mods I always do) since 1999. Whatever.

Who needs the forum if we can just google anything anyhow.

HMMMM......I have always removed the thermostats from all my cars and tossed them.... Including the one in my wagon........Never had one stick shut after that! Wagon runs great 160 degrees and gets the same fuel mileage it ever did..... Heater also works good.........

Wow.

So whats the advantage of running a lower temp t-stat then? Why run anything other than what the engine was designed for if there is nothing to be gained?

AzDon wrote:

HMMMM......I have always removed the thermostats from all my cars and tossed them.... Including the one in my wagon........Never had one stick shut after that! Wagon runs great 160 degrees and gets the same fuel mileage it ever did..... Heater also works good.........

in Arizona too,..


wow

MalibuSSwagon wrote:

So whats the advantage of running a lower temp t-stat then?

None, if the engine is left as designed. There is a school of thought that the LT1 engine, due to it's unique cooling system, may benefit from the cooler thermostat value when coupled with performance mods.

The traditional 180°-190° value keeps the cylinders at the optimum combustion temperature. In a traditional engine, the coolant hits the cylinders first, then the heated coolant goes on to cool the heads. However, in an LT1, the reverse-flow system cools the heads first then the cylinders, so the coolant is hotter by the time it gets to the cylinders. If you've bumped up the engine output with performance mods, and the heads are pumping out more heat, those cylinders might start exceeding the ideal combustion temperature. In that case, lowering the coolant temperature before it hits the heads helps keep the cylinder temperature down in the happy zone.

Removing the t-stat completely from an LT1 is a Bad Thing, performance mods or Arizona weather notwithstanding. The system promotes faster warm-ups and enhanced temperature stability by recirculating heated coolant, by-passing the radiator via a second seat in the thermostat. When that second seat is closed, the bypass is closed and coolant is forced through the radiator. When the second seat is open (or missing!) coolant by-passes the radiator. Therefore, removing the LT1 t-stat completely causes overheating.

"Many women who do not dress modestly ... lead young men astray, corrupt their chastity and spread adultery in society, which increases earthquakes"

Extraordinary claims, etc, etc...

What do you find extraordinary? That removing the LT1 thermostat can cause overheating? It is easy to demonstrate for yourself. Simply remove the thermostat from a known-good LT1 and work a bit (eg: pull a trailer up a hill) while watching the ECT.

The LT-1 engine cooling system is significantly different from that in other V8 engines. The coolant flow as described above results in considerably less variation in cylinder head temperatures, which is a major factor allowing a high compression ratio effecting increased efficiency (higher power output and better “gas-mileage”), Additional benefits are generally lower head temperatures overall and reduced cylinder wear.

The coolant flow in the engine didn’t come about by accident. It was carefully worked out by no less than Smokey Yunick, and adapted to production vehicles by GM engineers.

There may be reasons to reduce the thermostat opening temperature under very specific conditions, but its complete removal will drastically change the coolant flow, at best and, at worst, result in water pump cavitation at high speeds. Reduced engine life, reduced power output, reduced fuel economy, and possibly even short term engine damage are all likely outcomes.

I have two friends that build race motors. Both said stick with the OE 180 stat in the TBI. LT1 is covered above. Lower temps allow more build up of deposits and the enginge doesn't get hot enough to burn them off = faster wear, poor fuel economy etc.

The TBI stat is not 180, it's hotter.

The cooler T stat mod is aimed at cooler intake manifold temps,.denser air, so you can add more fuel, etc,. blah blah blah,..but an LT1 is not a wet intake,. so i,m not sure if the benefits could be actually measured,..

helpful in a 1/4 mile car? yes  icing down the intake is good for a couple of hundreths ,.cold intakes work best with pressurized motors,.pressurized intake air is hot.

When it comes to a T stat,. i have trouble believing anyone, especially in Arizona, not using one, and not overheating,

The coolant needs to sit in the rad to be able to be cooled,.the amount of time its in the rad is referred to as "soak" time,. greater the soak time,.coupled with sufficient airflow, outside ambient temps etc,. equals lower coolant temps,.then the coolant can absorb more heat from the engine to return it to the rad to cool it etc etc etc,..
To obtain "soak' time in the rad, there must be a way to stop the coolant from simply racing around from engine to rad not giving the coolant enough time to 'cool' in the radiator,.this is accomplished with a thermostat,. which allows coolant to flow around the engine until the coolant has absorbed enough heat,.and then opens to divert hot coolant back to the radiator and letting cooler coolant into the engine,.
Without out a way to slow down coolant speed, the coolant simply travels from rad to engine and back quickly enough that it does not have enough time in the rad to cool off enough to be effective,.as this cycle repeats itself the engine gets hotter and hotter,.
The mitigating factor in all this is how much heat the engine is generating in other words how hard is it working,. and also how much rpm is the engine turning,.the faster the water is pumped around with nothing to slow it down,. the faster it will heat up,.the harder the engine is working the hotter the coolant will get,.

I personally have had examples where the engine with a 180deg t stat would boil the rad and overheat,.,.but with a 195 they would keep their cool,.(not boil over) admittedly older iron with large engines and marginally sized rads,.

So a desert car, where the outside ambient is high to begin with, with no thermostat,. doing any kind of work,.would in my opinion make the cooling system overheat quite quickly,.

The summertime temps in Lake Havasu City, Az are over 110 degrees for over five months of the year....
Folks promoting the "soak time theory" almost never mention that while coolant is "soaking cool" in the radiator, that other coolant is impounded in the engine, receiving more heat than it would if it was just passed on through in exchange  for the coolant in the radiator.... I've proven to myself through a long succession of Chevrolet powered vehicles that they ALWAYS run cooler without a thermostat....I also have had no driveability issues with either of the TBI cars that I've discarded the stats from.
Stopping and starting the coolant flow builds unnecessary excess pressure throughout the system...Head gaskets, hoses, and water pumps all work a lot harder than they would otherwise need to and more heat is built up than would naturally occur....excess heat that needs to be disposed of.......And then there's the issue of stuck thermostats, which never stick open!... A little-known fact about thermostats is that one-in-three are defective right from the box! The main reason my wagon is without one right now is that after going to the parts store twice, I still didn't have a stat that would open at the prescribed temp, so I gave up!
It's always been my belief that heat is bad and that free and ample flow of coolant and air across the radiator result in happy temps!

TBI cars don't have the same reverse-flow cooling system as the LT1. You can certainly get away with running without a thermostat in the older cars with traditional cooling. There's some debate about longevity, etc. but there is certainly no harm in the short term.

I drove a tow truck when I was a teen, and 90% of all overheat calls I could fix by yanking the thermostat and cutting a quick gasket out of a cigarette pack.

Of course, all those failed thermostats would not have cause an overheat in the first place if a fail-safe t-stat had been installed -- they fail open, not closed. ;-)

Well......I tried a fail-safe stat and it never opened even once so it could stick open.......
While I'm sure there is engineering and testing (and maybe a little marketing) behind "Fail-Safe" thermostats.......I really don't see how they can logically make the claim that an item that is closed while at rest, would fail in the OPEN position When the VERY DEFINITION of failure is that is WON'T open......

Being almost 60 years old, my background is mostly simple ignition carbureted stuff......In the hot environment where I live, I found that almost every system under the hood of a vehicle is happier when you delete as much under-hood temperature as possible...... Excess heat under the hood can cause vapor- lock and fuel evaporation issues, can diminish A/C performance and lead to electronics and sensors overheating and failing. My wagon actually had a hot-start vapor-lock problem when I got it because the non-adjustable factory pressure regulator was only holding nine pounds of pressure (I bought a kit to make it adjustable and fixed it!)
Other things I'm willing to do to reduce heat are: larger capacity and/or aluminum radiators, fan clutch eliminator hubs, fender vents, hood vents, loovers etc.
Obviously, some of this stuff can't be done with the more micro-managed computer controls on some of the newer stuff..... Fortunately everything I've got that my wife will allow me to work on is over 20 years old!