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Thermostat what size you use

12K views 20 replies 8 participants last post by  ShotRod64 
#1 ·
Going to pick up a new thermostat since I have the water tank off and the one in there has been in since 2004. The one i have is 160. I can't decide whether to stick to 160 or go 180. It's always been a hot running beast so not sure what difference it would make and curious what others are using in their 390s or similar.
 
#3 ·
Deb,

I use a 190 because I heard that's the best temperature for the engine. If not true, I'd probably drop down so the car would warm up faster in the winter.

As far as a 190 causing more overheating than a 160, I don't really buy that. When the engine water is at, say, 220, both thermostats will be wide open, so it shouldn't matter which one you have.
 
#4 · (Edited)
I agree with Puttster.

I use the higher thermostats as well. 190-195. Just installed a 192.The owner I bought the car from (old school mechanic as well) explained it to me in great detail but don't remember it all. Just remember him telling me not to run anything lower than a 190. Something about the extra time the water is in the radiator will help cool the coolant and that 190-195 thermostats were stock in an FE.

The higher temp thermostats also help minimize wear on these FE's. (See older attachment from the forums)
 
#5 ·
I haven't figured out what the exact detail is for the thermostat sizes, big or small as I have found both sizes for the '64. I carried my old one with me to be sure as they both look small to me when just holding them. I had trouble finding the big one last time and this time. Not sure what he used for search terms but we tried mustang also. Then on the parts places they ask base or XL which makes no sense to me what difference it makes on a 390 for most of the parts. We might of ended up using a 352 galaxie base as the search in the end.

After a discussion with a man i stalked in a the parking lot at the parts store i am wondering if 180 would actually be better for cooling. You're gonna think non-ford content but it is! I followed cause it was bright green! Kinda faded, worn and scraped but it was green and wanted to tell the old guy i loved his vw bus color. I ended up talking for 45 mins, getting on the ground and looking under it and discussing antifreeze and ww2 planes. :) He told me it had a V6 and i was like REALLY? then asked if i want to see it, well of course you know i did! No traditional radiator in it either but instead the water runs through the front above the bumper and underneath (forgot the name) things from big AC units, makes me think of a transmission cooler cools it. He had to figure out how to get the water pump to pump and thought of how the hydraulics on planes work which gave him the answer. Get water level above the pump. He used a oil filter housing from a big truck to route water through and a water tank like the '64 has to fill the system. Holds bout 3 gallons. I forgot the year but said a Ranger V6. I don't know those from adam though. He did all this almost 20 yrs ago and has done a couple for other people. He said it's great to get up the hills in the mountains etc.

The planes come in when discussing why antifreeze was developed and the cooling of the plane engines so they could climb and also reach their highest speed without over heating. Along with pressure in the system vs temps of the system. Interesting old guy.

more green. Mine is opposite, green block, blue VCs.


 
#6 ·
engine is a heat pump. it uses the heat of combustion to expand gasses to push the pistons. if more of your heat is used to heat the coolant, less is available to expand gasses. ideally the coolant would be at amuch higher temp, but we have to deal with what the sys can handle
 
#7 ·
If the parts store has a problem finding the big thermostat ask for one for an early seventies Dodge 318. Let's say a 76 D100 with a 318. I know that fits. Even the gasket is right.

Sent from my SGH-T399 using Tapatalk
 
#8 ·
Hey Deb - fortunately, this question was answered several times in the last several years. Unfortunately, many of those posts disappeared with the forum ownership changes, though a few like this still survive. I haven't found the ones where the additional expertise of the thermodynamic engineers and the extra charts and graphs are located, but much is still covered in the link above.

In a nutshell; using stuff like the graph mvannote posted earlier and others, you can see the "sweet spot" for temperature versus wear, power, mileage, and emissions. This temperature for most engines like ours, and in street use, lies roughly between 175 and 185 degrees during operation. The thermostat rating (cracking temperature) stamped on the thermostat must be lower to achieve that operational coolant temperature range. A 160 to 170 thermostat will generally achieve this, and is likely why yours has one.

There are pros and cons to every temperature, and for example, if you want to reduce emissions you should raise the temperature above this point. If you want increased mileage and reasonable power, stay in the sweet range. If you are after max power, at the cost of some mileage and emissions, operate below that range.

One caveat not often mentioned is the temperature the engine is broken-in and worn into already. As the engine changes temperature, the dimensions change with it, and operating permanently at a new temperature will experience a new 'break-in' period. During this period, there will be greater wear as the parts establish their new seating and wear patterns. There are additional negatives, such as increased carb fuel boiling and vapor lock issues that follow higher temperatures. So, I generally suggest not changing the current temperatures on a used/ broken-in engine, unless the reasoning and benefits are strong. Hope that helps.

David
 
#11 ·
PSIG, I believe at one time it was a 180* then when i was having hard starts then the fuel boiling it might of been when it was changed to 160* trying to resolve the issue. But i'm not sure, too many days(yrs) ago.

I'm just bout ready to start getting all the bits and pieces back together on the car. When all that is done then it's alternator time. What kind of schedule do you have in say approx 2 weeks?
 
#13 ·
You're a busy guy! I've got til may 31st. Only cause I'm hoping to have it done before I head to Oregon for the cruise with dad so couple weeks should work.
 
#16 ·
Was on the napaonline site looking for parts and entered thermostat just to see what would popup options wise.

195 is the "OEM Specified Temperature", all others are alternates.
Yeah, that's a good example of how the suppliers have corrupted the spec's on our old cars over the years, specifying what they make rather than what Ford specified. For Ford's official side of this, look at the original Ford service manual (FSM) for your vehicle and year. Note that it will show two thermostat specifications. One for cars/trucks equipped with low-temperature thermostats, and one for those equipped with hi-temp thermostats. Neither match what NAPA says. :(

BTW, which thermostat your car received from the factory depended on many factors, and not just 192°F for cold climates or 160°F for hot climates, but primarily the emissions requirements of the destination, intended use, auto/manual trans, AC equipped, and a bunch more. Nobody reads the manuals these days, and there is a wealth of info in them that stop much of the guessing pretty fast.

BTW #2, you have repeatedly posted a conversation about cooling from another forum. Please specify what information in there you are referencing or questioning, as the entire thread contains only a couple small spots of valid information. An example of misguided assumption (followed by some grand hypotheses) was that one thermostat has two different operating ranges depending on the outside temperature. As seen above, that is entirely untrue, although I suppose it is entertaining in a way.

I think the question many should ask themselves, is why Ford would put a low-temp thermostat in one car, and a high-temp version in the next car on the line? Or, why would a car ordered for Alaska get a different thermostat than one ordered to a DSO (on the data tag) in Arizona or Morocco, and yet a another change for one ordered to California?

David
 
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