Thermostat at 180F or 160F ?

I can only say what I was told by the experts on the 351C both on this site and other Ford sites - the 160 is too cold and that the 180 Robert Shaw or Tim Meyer equivalent (meaning proper thermostats with brass restrictor plate in the block) should be used.  I ran the correct 180 and never had a problem.  

I don’t think any Pantera drives around in a temperature range that you would think your engine is running too cold..

i went 160 degrees just with the idea that it’s Harder to cool a heat soaked engine block back down … Poor little engine sitting in that hole back there… I don’t think running too cold is even an option.. (the engine sitting in the front of the car is a totally different animal in my opinion)

all the above is just me talking… Haven’t have any miles on it yet…

Just relaying what those associated with the 351C have stated.  So what does your 160 degree thermostat show on the gauge when hot?

Back in the early nineties at a POCA Fun Rally Tech Session with a panel of experts, the 160/180 degree thermostat question came up.  The opinion of the panel was 180.   Panelist Lance Nist stated that, IIRC, FoMoCo had found less engine wear with 180 'stat compared to a 160.   FWIW.

                 Chuck Engles

Correct:

More HP at 160 but a lot more wear and more sludge build-up as well.  

Hence why the race community use the 160 cause they rebuild their motors much more.

I would like to hear real world experience of what the motor actually runs at when hot using a 160.

I'm no expert, but once the thermostat opens the coolant temp will settle to whatever temp the cooling system can maintain.

I'm guessing most Pantera's never drop below 180F once they are heated up so thermostat would really only be in play during warm up.   

I'm in Arizona where it can be 100F when you wake up in the morning, so I could be wrong on this one.   

180°, IMHO, is the correct rating

order your thermostat from Tim Meyer to be sure you will actually get the correct thermostat. Parts counter thermostats are a complete toss up whether they have the correct number even listed in their catalog

Larry

...Tim Meyer supplies the correct Robertshaw thermostats 160F, 180F and 192F. He bought the machines to produce the Correct Copper Hat, as it's called.

I use to create the Copper skirts and install them on the RS thermostats...I have had over 640 Modified Robertshaw Thermostats pass through Me, Documented!

Most don't know the FORD engineers designed the 351 Cleveland engine to run a195F Thermostat. I suggest the 180F is Perfect for a Street Running, some 'Laps', Pantera.

Point being, in all of those Customers, Only 2 ever requested the 160F RS Stat. I talked One person out of it for the following reasons. The second person INSISTED on having a 160, he was going to drive cross-country and wanted the Cleveland to run 'Extra Cool'. It doesn't work that way! He received the Only 160F stat I ever created.

The Cons of running a TOO Cold Cleveland Engine:

Accelerated Cylinder Wall wear.

Harder/Stumbling Idle at Cold morning starts.

Inefficient Fuel Atomization with-in the Intake Manifold.

Passing unburned, Raw fuel to excessive emissions, Leading to lower gas Milage.

The 160F Opens sooner and possibly, never closes...the coolant passes through the Engine too fast. for the coolant to Absorb an efficient 'Amount' of Heat. The Stat MUST Cycle, open/closed, for the Coolant to take heat away from the Block and Heads.

"Heat is Energy", the Cooler Engine produces reduced Horsepower. That's Why a Over-Heating Engine IS More Powerful.

There's More.

Why the 195F (192F) Thermostat should be used for Racing Only, In My View.

Go with the 180F from T. Meyer and don't forget the 'Brass Restrictor Plate'!! You'll be Happier for it, when She has a Perfect Idle.

MJ

P.S.

I took the Pantera to the Mojave Desert, August 1-4 2019. 180F RS Stat. Ambient temp 118F, Cruizing at 85 MPH, all day, the Engine Temp remained at 192F-195F. Restrictor Plate was Installed.

If your engine is going to overheat anyway, all that a 160 thermostat will do is buy you a little more time before it cooks. Rather get the cooling sorted and run it at 180, or even better at 192.

@jwelch68 posted:

I'm no expert, but once the thermostat opens the coolant temp will settle to whatever temp the cooling system can maintain.

I'm guessing most Pantera's never drop below 180F once they are heated up so thermostat would really only be in play during warm up.   

I'm in Arizona where it can be 100F when you wake up in the morning, so I could be wrong on this one.   

Where I live in Arizona, any given morning will be cool enough to have the engine run at 160 degrees with a 160 degree thermostat. That is just too cold, because it causes excessive engine wear.  The 180 degree thermostat is optimal, but on a hot Arizona afternoon the engine will operate at whatever the cooling system can handle above 180 degrees. These modern engines in the newer vehicles all seem to operate at above 190 degrees and some as high as 205 degrees.

I've tried 160 and 180. The 180 won. That engines runs like crap until it warms up.

While it is important to not have the system boil over, the temperature that you should be looking at is the oil temp.

You need that to get hot enough to boil out the moisture.

Therefore it isn't bad to have oil temps of 212 to 220 which means that the water temp would be around 240.

The 192 thermostat is the "quick warm up" one. The 180 is a good compromise between the two.

Remember that the Pantera is a high pressure cooling system and a 240° water temp is just about right for it.

A lot of times Panteras having temp issues just need to have the system power bled to get the air out.

All engine clearances are set with that temp in mind.

You need some heat in the system, oil needs to be 160 min and 200 is fine for oil...

I'm using an oil cooler and an inline Mocal oil thermostat. With the big Aviad pan it takes a bit to get the oil hot.

New Windsor engine in mine... I'm running 30% blanking on my radiator to try and keep the temps up. Ambient is around 55 F at the moment... I do have a 180 EMP Stewart thermostat which has bypass holes, so it's taking a dog's age to get hot....

The reality is that the Panteras were delivered new with the 192° themostat from Ford.

The only upgrade needed was to change out the original 4 blade cooling fans to the eight blade ones.

These cars were tested by Ford in Arizona heat and by the '74 model, everything was fine.

I use the 180° thermostat and pressure bleed the cooling system with a hand pump. You can hear the system gurrgling as the air bubbles get pushed out.

If you start to mess with this system, you are attempting to re-engineer it and if you think that you are smarter then the Ford engineers are, be my guest but here's the thing, you aren't.

The largest reason they overheat is 1) the '71 cars system design needed help. It wasn't fully developed.  2) people do not understand how to get the air out of the cooling system and what that means.

You need to use a pressure system like the one to test the pressure cap sealing to do it. It is actually very simple and people are still reading tips and procedures posted 30 years ago on the internet that are incorrect and misleading.

Well, I guess I’m changing thermostat..

180 it is..

...It has been mentioned that Newer Cars can run at 190F-205F Degrees, and probably much Hotter.

This is because the Engine Exhaust must be Hotter to Activate the Catalytic Converters!

I know of No Panteras running Cats.

When Running the 180F Stat, I have personally had My 351C at 230F on the Digital Gauge, without Boil-Over. Although Out on the I-5 Freeway In California, in the Middle of Summer. Ambient temps at 110F...things were Getting a Little Nervous, after 3 Hrs. at 90 MPH and pulling off the Freeway and shutting down to refuel. But, it never became a problem. It's all about 'Holding' the System Pressure!! I run a 16 lb. Cap, any Cap, Lower, expect to Boil-Over when things get 'Critical'! In My Experience.

MJ

@marlinjack posted:

...It has been mentioned that Newer Cars can run at 190F-205F Degrees, and probably much Hotter.

This is because the Engine Exhaust must be Hotter to Activate the Catalytic Converters!

I know of No Panteras running Cats.

When Running the 180F Stat, I have personally had My 351C at 230F on the Digital Gauge, without Boil-Over. Although Out on the I-5 Freeway In California, in the Middle of Summer. Ambient temps at 110F...things were Getting a Little Nervous, after 3 Hrs. at 90 MPH and pulling off the Freeway and shutting down to refuel. But, it never became a problem. It's all about 'Holding' the System Pressure!! I run a 16 lb. Cap, any Cap, Lower, expect to Boil-Over when things get 'Critical'! In My Experience.

MJ

Totally agreed. The only thing is don't go higher then 16psi but 15-16 psi is perfect for this system and is what makes it work at 240°F without boiling over.

You are good on oil temps up to about 220F°. Race cars typically will go another 15 to 20 hotter. That's why you don't use the $.99 a quart oil.