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

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..

@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.

@marlinjack posted:

...The Engine Oil Gauge 'Digital', was Blinking, meaning the Oil temperature had gone beyond the Sender and gauges Limit of 250F*. When I turn on the Rear Oil Cooler FAN The Temp comes down to 230F- and the Gauge has stopped Blinking.

NOTE: I have the Fan Back to blowing Through the Cooler and OUT the Back of the Grill. I tried reversing to Draw Air IN from behind the Vehicle and The Cooling was ineffective, Zero!

Proof: The Fan Mounted on the  cooler can NOT Draw air through the Fins (from Outside-In), AS Efficiently as the Fan Blowing air Onto The Cooler and then Through the Fins. Because the Air Cools 'All Around The Cooler Case' and through the Fins.

MJ

* No telling How Hot the Oil Got...the Gauge just stops Registering Beyond 250F. And that's with Valvoline VR-1 20W-50

I am going to have to disagree with you about a rear mounted oil cooler and its air flow direction. I have had a rear mounted oil cooler on my car for years and it works quite well. The fan is thermostatically controlled to come on when the oil going into the cooler gets to about 180 degrees. The oil cooler fan is shrouded, so the air can not bypass the cooler fins. Many times on a hot Arizona day the oil cooler fan will come on and then shut off. I have an oil temperature gauge inside the car and a light that comes on when the oil cooler fan is running. The fan cycles on and off at 75 and 80 mph highway speeds, which tells me that the cooler is getting enough air flow. I always have the rear trunk liner installed, which by factory design was the way the air conditioning condenser worked with air being pulled in rather than blown through. Some car owners have done tests that show that beyond 100 mph the stock rear condenser design does not work because there is a vacuum being created at the rear of the car. Many owners don't like to drive their Pantera with the trunk liner installed and by blowing through the condenser it might make sense to reverse the cooling fan direction and blow through it.

Gents,

thank you all for your valid feedback and advice. Appreciate!

I finished my research and came for me to partly different results which I like to share (and later on prove or disprove in reality and share again, of course).

First of all I like to agree that the best oil temp is around 212F. However when the right water temperature comes into play the opinions here in the chat are in favor of a hotter temp towards 180F (or even hotter).
Now let me quote my engine builder who is doing high performance tuning of Cleveland and Windsor engines for the last 36 years successfully:

"I was told this many years ago (edit: colder engines produce more wear), but have never experienced it and I have been tuning our engine packages to 160f and colder for many years without any complaints from customers of excessive wear. Nor have I witnessed excessive wear when freshening one of our engine packages.

Car manufactures do run engines very hot these days compared to many years ago as it helps to burn every drop of fuel and it greatly helps with emissions. Our packages are not built around being emissions legal. They are built around making max power for a given fuel. If you try to run the engine hotter there will be more hot spots in the chambers and it will cause detonation resulting in engine damage.

Just going from 160F to 180F would probably cost you 10-15 hp and you'd be risking detonation.
If we lowered the compression ratio so as you could run the engine at 180F without the risk of detonation you'd probably loose another 10-15hp
So in total you could lose 20-30hp just from running the engine a little hotter.
I have seen far more damage created from running a high performance engine hot than compared to running it cooler.

On another note I find that once you get an engine hot it's much harder to cool it down compared to not letting it get hot in the first place."

I must add that driving conditions are severely different here in Germany than in the US. When you talk about 75-80mph on the interstate we talk 120mph cruising on the left lane of a three lane Autobahn. That's fairly average. If we go fast we are doing 150-200mph (of course with the right cars). If we go slow in that lane its still about 95-100mph. The strain on the engine is and will be a different ball game.
To keep my water (and finally oil) temp down I will apply an electrical pump (55g/m) and two SPAL fans with a controller by applying a high-performance mesh cooler and large oil pan. I hope the precautions are rightly set.

I will report back when its ready to run.

Here is what my engineer builder says on this subject…

“It is true that engines make a little more power cold, so going from 195 to 160 is about 10-15 hp depending on the horsepower range of engine, 700 hp engine will be about 15 from what we seen on the Dyno.  

One (1) whole compression point is 20 hp and 20 foot pounds of torque that is a mathematical number that is on engines and is an increase from 1000 RPM to 8000 RPM as it is a linear increase because it’s mechanical, but going from 195 to 160 does not mean you get a jump on extra point on compression ratio, that’s part of the build.

Compression ratio has a relationship with the octane in the fuel and timing.

If you try to run your motor down to 160 two things come to mind:

1. Good luck with that in Arizona

2. if you build a motor to run that cold, you have to run looser piston to cylinder wall clearances because the block doesn’t expand as much so the cylinder doesn’t grow as much.

We have to do that on boats when we run boats at 130-140° water temperature because they’re pulling up lake water and we have to add .002-003 piston clearance on those motors because the cylinders don’t grow as much.”

So basically, just running your engine colder with no other changes MIGHT give you an (unnoticeable) power increase (3.5 HP on a 400 HP motor).  To get benefits from it, you have to pair it with a number of other related modifications… like just about everything else you can do to get more horsepower!

Rocky

I have a Pantera Electronics fan controller in my setup that uses a separate temp sensor to start the fan ramp up.  Don't quote me but I think the first fan step starts around 150F.

In my car the first step is reached within 10 minutes of driving and typically never turns off unless ambient temp is 70-80F and I'm cruising around 80MPH.

Maybe it's an Arizona thing, but I'm not convinced the cooling system runs less than 180F unless you are in low ambient climates and have plenty of air flow.

forgot to add that I should get some accurate coolant temp readings in this summer once the Sniper 2 EFI is installed. 

@jwelch68 posted:

I have a Pantera Electronics fan controller in my setup that uses a separate temp sensor to start the fan ramp up.  Don't quote me but I think the first fan step starts around 150F.

In my car the first step is reached within 10 minutes of driving and typically never turns off unless ambient temp is 70-80F and I'm cruising around 80MPH.

Maybe it's an Arizona thing, but I'm not convinced the cooling system runs less than 180F unless you are in low ambient climates and have plenty of air flow.

On a 100 degree day at 75 mph my engine will run at 180 degrees because that is what the thermostat is rated at. If I put a 160 degree thermostat in, then it would run at 160 degrees. I am actually cheating here because I have an all aluminum Fontana engine with sequential port fuel injection and a redesigned cooling system. The engine in producing about 550 horsepower at the flywheel and it is bored .070 over and stroked to 390 cubic inches. I have seen a couple of Panteras with Cleveland blocks that do run quite cool, but mine never did.

@jwelch68 Quote:

If I put a 160 degree thermostat in, then it would run at 160 degrees.

This might be the case if your cooling system overall is able and capable to achieve 160F under these weather conditions. Maybe it runs at 175F and that’s it.

@FWJ posted:

@jwelch68 Quote:

If I put a 160 degree thermostat in, then it would run at 160 degrees.

This might be the case if your cooling system overall is able and capable to achieve 160F under these weather conditions. Maybe it runs at 175F and that’s it.

When I got my car back from Pantera Performance Center the engine was running at 160 degrees. That was indicating on a good Autometer water temperature gauge and not the factory Veglia gauge. When I called Dennis about this, he told me that he put a 160 degree thermostat in my engine because he thought that all of the Pheonix Pantera owners used them. The problem is that I live 200 miles from Pheonix and at over 4100 feet. The mornings in my area can be very cold and it is a different climate zone than Pheonix. I took the 160 degree one out and installed a 180 to get the temperature up to where it needed to be. If you are using a Cleveland block, there is the potential problem to have thin spots in the cylinder walls due to the thin wall casting method that was used to build them. Some blocks have the problem and some don't. If you bore a Cleveland block that already has thins spots, then you are making your cooling problem worse. Now put in a bigger camshaft and up the compression ratio and the problem gets worse because you are making more power.