180 or 195 Thermostat (Page 2/3)
olejoedad AUG 10, 02:07 PM

quote
Originally posted by Dennis LaGrua:

I've always maintained that a 180* thermostat was better for engine life. Get stuck in traffic with the 195* thermostat and coolant temperatures can soar. On a hot day with the A/C on even overheating may occur. Fieros were also designed to take in cool outside air to the intake because it is beneficial.
On modified or boosted engines the 180* stat is important as less heat = additional detonation protection and ability to generate more horsepower.




I can't agree with your assessment that a 15 degree difference in thermostat rating will have an effect on engine life.
PhatMax AUG 10, 04:11 PM
A 195 does not give you much room before things go too hot. If you want your engine to run at 200+…have at it. I still maintain that the higher temps were for emissions only. If you think 170 deg coolant won’t heat your car then why do boiler systems that heat up entire buildings at 180deg running thru hundreds of feet of pipe work ? I’m with Dennis on this..
theogre AUG 10, 05:32 PM

quote
Originally posted by Dukesterpro:
Im going to disagree with one aspect of what Orge said. Be warned everything else he mentioned I believe to be 100 percent accurate, especially that people rewire their fan circuit to mask unlying issues.

However, I am an electrical engineer by trade and have a good understanding of the motors that are used in the blower and cooling fan. Running them all the time will not induce significant premature failure. There is a common misconception among old-school car mechanics that the fan running longer reduces the fan's lifetime and it's simply untrue. What actually kills the motors is when you increase the amount of time it cycles in operation (stop-start). A fan that comes on once and stays on the entire time the car is running is going to last longer than a fan that starts and stops 5-6 times. Peak current is what harms fan motors the most, which is what is experienced when you dump 12v on a stopped fan.

Whether or not a 210 thermostat will cause more cycling or not I cant tell you. But running a fan longer wont hurt it as long as you arent cycling it more!

Running rad fan and other motors a lot often "Violates" Duty Cycle of that part and Power cycling is just a part of a Duty Cycle Spec.

The majority of "Fan" Failures for vehicles and other things are not Electrical problems even for Brush motors.
Car Rad Fan, heater blower, and others are make "Cheap" w/ mostly Oiled Bronze/Brass Bearing than causes a lot of failures.
120-240vac (depending where you live) home fans, vac cleaners and more often dies because bearing have bound up then the motor heats up and when ignored fries 1 time thermal fuse buried in the motors.

Some Rad Fan motors are 2 speeds and run at lower speed most times and they last longer but often fail for bad bearings.
Most PC case and CPU fans run lower speeds too and still have same problem w/ bearings & those are Brush-less units.

Yes Can have low volts cause by anything in a car making any motor to draw more amp so something cooks, wear out bushes for various reasons, and other issues but most times is "bad" bearings as root cause.
Dukesterpro AUG 10, 05:38 PM
It one hundred percent violates the specified duty cycle of the fan motor. However, I will say it won't make a noticeable difference in a good-quality fan's life. The duty cycle is typically established to only fit the need that it will fulfill in the car and not what the device is actually capable of doing.

The point you made about cheap Chinese bearings and bushing is correct though.

But my point still stands increasing the cycling of the fan will be far more harmful than continuously running it
MasterBaker AUG 10, 05:44 PM
3/4 months out of the year we are high 80’s to mid 90’s. Living in a higher populated area there’s a lot more stop and go traffic. Given temps and driving conditions thinking 180 degrees may be best. I’m afraid temps could quickly get to high.

[This message has been edited by MasterBaker (edited 08-10-2023).]

sleek fiero AUG 10, 10:41 PM
I am in a different situation now with an aftermarket ecu but for the last 28 years I ran stock ecu with a FS stage 2 chip and the recommended 160 thermostat and 165 fan TS. It ran flawlessly for the 28 years and Performance was great in all seasons. With my new ecu I had to bump it up to 180 thermostat and 190 on the fan. I also had to upgrade my rad to a 3 core aluminum and delete my ac as the new version of my engine produces much more heat than the original 2.8. I believe each owner will have to adjust their cooling system to accommodate the upgrades they may have made to their engines !!! sleek
theogre AUG 10, 11:07 PM

quote
Originally posted by Dukesterpro:
The point you made about ❓cheap Chinese❓ bearings and bushing is correct though.

I did not say that because The Chinese had little to do with these motors.

When GM and others made car parts they used same Oil Bronze bearings for the US made motors and had same problems.
GM E-motors for Fiero and thousands more was built by GM (Maybe Packard Division like many other E-parts.) or 1 of the US Contractors.

I've replace Many 60's to 80's fan/blower and wiper motors in GM Ford AMC and Chrysler vehicles w/ same type motors w/ same "cheap" bearings build way before moved/sold most manufacturing to Mexico China and worse countries. Nearly all had "bad" bearings.
Dennis LaGrua AUG 12, 08:48 AM

quote
Originally posted by olejoedad:

I can't agree with your assessment that a 15 degree difference in thermostat rating will have an effect on engine life.



While I have no proof that higher heat levels can decrease an engines life and will not challenge your comment; lower temps should help decrease the chance of detonation on a modified engine. I believe higher temps can decrease the life of an automatic transmission. I run the 4T65eHD and the 180* Stat keeps the coolant cooler should add efficiency to the integral transmission cooler on the radiator.

------------------
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"THE COLUSSUS"
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" ON THE LOOSE WITHOUT THE JUICE "

olejoedad AUG 12, 11:38 AM
Knock sensors were invented for a reason.

We ran lower temp thermostats on wet manifold carbureted engines.

Modern, modified fuel injected engines with knock sensors are just fine with higher temp thermostats.

It's an automatic transmission temperature stabilizer, not a cooler.

[This message has been edited by olejoedad (edited 08-12-2023).]

pmbrunelle AUG 12, 12:35 PM

quote
Originally posted by PhatMax:

I’m not buying it, the higher temps were for emissions…not to make the motor run better. The only place you want heat is in the exhaust to help with flow. Fuel only needs to be heated to about 110 deg to properly vaporize. Too much vaporization is not a good thing.
If someone can send me a technical paper on why higher temps are better I’d be more than happy to change my mind.



I have tried both 180 °F and 195 °F thermostats on V6 Fiero engines. I like the 195 °F thermostat more. I am not building my Fiero to meet any emissions test.

At the higher coolant temperature, the engine needs less acceleration enrichment, and the throttle response is a bit better.

This is the warmup enrichment table I tuned on my stock-ish V6 Fiero. It is a multiplier that enriches the mixture as a function of coolant temperature:

(coolant temperature axis is in °C)

Most of the extra fuel added by this table ends up unburned, because of poor vaporisation. This table exists to compensate for poor fuel vaporisation at low coolant temperatures.

Every single time I take the car, as it warms up, it passes through 180 °F, and while it drives okay at that temperature, I like it better when it reaches 195 °F.

It is hard for me (or for many others) to discuss fuel temperature, since fuel temperature is often not measured/recorded. It is however easy to discuss coolant temperature, and by proxy, the temperature of the internal surfaces of the intake ports / runners. Where did you pull 110 °F from? Warmup enrichment on my Fiero continues well beyond that, as you can see in the picture.

How is too much vaporisation a bad thing? Fuel that passes through the combustion chamber unburned is wasted and does not have any benefit that I can see.

[This message has been edited by pmbrunelle (edited 08-12-2023).]