Author Topic: Cooling temperatures  (Read 2008 times)

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Stangman

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Cooling temperatures
« on: August 28, 2022, 09:56:52 PM »
Yes I know this has been talked about buuuut. So I have a 180 thermostat and a fan switch that comes on at 190 and will shut off at 175. I would like it to run cooler but if I was to put a 160 thermostat in there I think the fan will come on and never shut off being that an FE jammed 8n a mustang engine compartment just will never see anything under 160. As it is anything over 85 degrees and my fan stays running like I have it now. So what I’m asking is what cooling combinations are people using and are the working like they are supposed to and I mean fan on and off and then cycle again

blykins

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Re: Cooling temperatures
« Reply #1 on: August 29, 2022, 04:40:57 AM »
I would keep it the way it is. 

I like to see coolant temperatures up around 180-195 on a street car.   Obviously on race stuff, it's different. 

Coolant temps of 160-170 are not as good for the engine. 
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My427stang

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Re: Cooling temperatures
« Reply #2 on: August 29, 2022, 06:38:48 AM »
I agree with Brent If you can figure out a way to keep it running at a consistent 195, you'll be doing it a favor.  However, if you are saying it won't run thermostat temperature or close to it, leave the warm thermostat in and think airflow not water flow.

Although a bigger or better fan is probably step 1, exit airflow matters too.  On my Mustang, I added the Boss 9 scoop for clearance, but dropped temperatures in traffic dramatically with no other changes.

Same with some late models that need a spoiler to make a low pressure area under the car.  They can heat up when you remove it because the fan can't push the air out alone

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Ross
Bullock's Power Service, LLC
- 70 Fastback Mustang, 489 cid FE, Victor, SEFI, Erson SFT cam, TKO-600 5 speed, 4.11 9 inch.
- 71 F100 shortbed 4x4, 461 cid FE, headers, Victor Pro-flo EFI, Comp Custom HFT cam, 3.50 9 inch

jayb

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Re: Cooling temperatures
« Reply #3 on: August 29, 2022, 08:33:00 AM »
I've always run 160 degree thermostats, been doing it since the late 1970s.  I've always found that the engine runs better with the lower temp thermostat, and don't agree that it is harmful to the engine in our applications.  Maybe it would be an issue if you are trying to get 150K miles out of your engine, but none of us are trying to do that.

I think one factor that is not appreciated is that temperatures internal to the engine vary quite a bit.  Think about the temperature of combustion, which can be over 1000 degrees.  With those kinds of temperatures being generated internally, is a change of 20-30 degrees in the coolant temperature really a significant factor in the longevity of an engine expected to last 20K miles?  I think not.  However, a change of 20-30 degrees in the coolant temperature leads to a proportional change in the air inlet temperature.  Percentage wise that can be a big change, which is why the engine feels stronger on a cool day, or with a lower temperature thermostat.  Seems like a lower temp thermostat is a pretty good tradeoff for a performance engine.

My electric fans are set to turn on at 180, and off at 170.  They cycle constantly in city driving, but on the freeway the temperature drops to 160 and the fans don't run.  I think this is probably a function of the tight engine compartment, where a whole bunch of airflow at 50+ MPH is required to really get enough air through the radiator and engine compartment, and drop the temperature all the way to the thermostat rating. 

JMO, of course  ;)
Jay Brown
- 1969 Mach 1, Drag Week 2005 Winner NA/BB, 511" FE (10.60s @ 129); Drag Week 2007 Runner-Up PA/BB, 490" Supercharged FE (9.35 @ 151)
- 1964 Ford Galaxie, Drag Week 2009 Winner Modified NA (9.50s @ 143), 585" SOHC
- 1969 Shelby Clone, Drag Week 2015 Winner Modified NA (Average 8.98 @ 149), 585" SOHC

   

Jb427

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Re: Cooling temperatures
« Reply #4 on: August 29, 2022, 09:11:01 AM »
Is it able to hold that temp?. That is the most important part.

If you want your fan/fans to cycle i think that will be tough in that type of engine bay.

You would need a cooling combo that can pull the water temp back to below 175. if your system can't do that now when it is 85deg air temps hard to say what a fix for that is.

Keep in mind that all a cooler thermostat will do is allow the water to have full flow sooner cheapest option to try as well. Too much flow can be bad too not enough time for the rad to do its job.

Rory428

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Re: Cooling temperatures
« Reply #5 on: August 29, 2022, 10:18:31 AM »
Like Jay, I have been running 160 degree thermostats "forever", including in the 390 in my old 74 F350 car hauler. I drove that truck for 26 years with the 160 Tstat, sold it 8 years ago, and to the best of my knowledge, it is still is still in use. In all those years, I never had to add any oil between changes, so I have to question the "rapid engine wear" from running "too cool". I have seen many more engines damaged from excess heat than running cooler, and I would much prefer having a 30 or 40 degree safety margin if I got stuck in gridlock for a long border line up, event parking,etc, with my engine at 165-170, then if it was already at 190 or 200. And no one can deny that a cooler running engine makes more power. I think much of this "cool is bad" myth came about from a study years ago concerning engine temps vs wear, which did show very low temps (like cold start up, to about 120 degrees) absolutely did show accelerated wear, but in my opinion, it was showing the wear from cold starts, not so much from lower coolant temps. Once the temp got up much over 140 degrees, the graph line was not much different than 190. I assume hotter coolant  makes the oil less likely to sludge up, but how many of us are driving our FEs 10s of thousands of miles per year, and going over 6000 miles or more between oil changes? My F350s 390 rarely saw more than 2000 miles a year, and had a oil change at the beginning  of each racing season, and I changed the valve cover gaskets after about 20 years of the 160 Tstat, and the heads and valvetrain were spotlessly clean
1978 Fairmont,FE 427 with 428 crank, 4 speed Jerico best of 9.972@132.54MPH 1.29 60 foot
1985 Mustang HB 331 SB Ford, 4 speed Jerico, best of 10.29@128 MPH 1.40 60 foot.
1974 F350 race car hauler 390 NP435 4 speed
1959 Ford Meteor 2 dr sedan. 428 Cobra Jet, 4 speed Toploader.

Falcon67

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Re: Cooling temperatures
« Reply #6 on: August 29, 2022, 11:01:54 AM »
I never run anything under 180 is a door car/street/strip.  Too cold reduces oil life and in most cases makes you "chase" the temp because the heat exchange doesn't work as well.  Especially with an aluminum radiator, you want that water hot - 180~195 - to get a good delta between ambient and the heat exchanger (radiator).  hot water = cool engine.  The dragster runs methanol and no thermostat.  I try to head for the water box at 170 and roll into stage at 180 for a pass.  I make the turnout at 200 and it'll be back close to 180 by the time I get to the pit. I don't have any of the milky oil issues and such that some people running methanol seem to have.

My427stang

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Re: Cooling temperatures
« Reply #7 on: August 29, 2022, 11:37:05 AM »
I have run all kinds of thermostats too, the thermostat doesn't matter the fluid and material temps do.  In the end, a stable temp is the goal, and unless the cooling system is up to task, a wide open thermostat doesn't know what temp it opened.  I like to see a cooling system that can run at thermostat temp, then use a temp that ensures water is burned off on the street. 

As far as internal temps, diesels taught me the benefit of water pump head pressure too (not expansion pressure).  The harder you can push that water into those two FE outlets, with some restriction at the water neck outlet, the more consistent temps will be internally. 

I still think if the OP has a temp problem, not sure if he does, then look at airflow. 

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Ross
Bullock's Power Service, LLC
- 70 Fastback Mustang, 489 cid FE, Victor, SEFI, Erson SFT cam, TKO-600 5 speed, 4.11 9 inch.
- 71 F100 shortbed 4x4, 461 cid FE, headers, Victor Pro-flo EFI, Comp Custom HFT cam, 3.50 9 inch

Stangman

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Re: Cooling temperatures
« Reply #8 on: August 29, 2022, 11:51:58 AM »
I think my temps aren’t that bad they stay between 187 and 192 not moving. I just started the new motor and was talking to Blair and he wanted it to run cooler but I’m not sure in my car with shock towers if it’s possible. I have a Griffin 2 row 1 1/4 tubes and a dual 11 inch fan setup with the 180 thermostat with a sender that tells the fans to come on at 190. If I get a 160 thermostat the fans will com on at let’s say 170 if I get a sensor that is set up like that. But it’s never gonna go below 160 for the fan to shut off. I don’t know.

My427stang

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Re: Cooling temperatures
« Reply #9 on: August 29, 2022, 12:21:03 PM »
Well Blair built it and wouldn't argue with him over something he knows the inside of, but those temps, stable at idle, sure don't seem to be an issue for me.

If you were percolating fuel, vapor lock, or runaway temp at idle, then I'd change my tune, but it sounds like it's working pretty well.

I do think you are right though, IF a 160 dropped it to 160, then the fan would never shut off unless you had an adjustable or different controller. 
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Ross
Bullock's Power Service, LLC
- 70 Fastback Mustang, 489 cid FE, Victor, SEFI, Erson SFT cam, TKO-600 5 speed, 4.11 9 inch.
- 71 F100 shortbed 4x4, 461 cid FE, headers, Victor Pro-flo EFI, Comp Custom HFT cam, 3.50 9 inch

Jb427

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Re: Cooling temperatures
« Reply #10 on: August 29, 2022, 12:41:12 PM »
I think you may be confusing the thermostat with what ever sensor you have working your fans
if your running a 180 thermostat that will open to allow full water flow at 180deg buy lowering that opening temp to 160 that just lets the water flow unrestricted at 160deg that should not change when your fan turns on or off if your fan is set to come on at 180 then it should come on at 180 that will also be the same time that the thermostat should be opening allowing unrestricted water flow if you had a 180 installed. if you have a 160 thermostat installed and have your fan set to come on at 180 then at 160 deg the thermostat will open and allow full flow of water through the system your fan will still come on at 180 and if flow and cooling is good enough it should turn off the fans once temp goes below the temp you have set up eg 175 but you will still have full flow of water cycling through the system as the thermostat should be only close if below temp goes bellow 160deg. That will only ever happen like Jay said on the highway driving or freezing air temps
« Last Edit: August 29, 2022, 12:49:31 PM by Jb427 »

Stangman

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Re: Cooling temperatures
« Reply #11 on: August 29, 2022, 02:06:44 PM »
thanks JB but I do understand its just that the lower the themostat the less chance I have of having the fan cycle. I guess I could save up for the next size
radiator. I have a crossflow and have one side of the frame in front notched. I know Jay was saying he has both sides notched. That would give me another 2 to 3
inches of radiator not to mention I can run dual 12 inch fans. After paying for motor funds are alittle low but do want it right.

jayb

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Re: Cooling temperatures
« Reply #12 on: August 29, 2022, 02:31:57 PM »
I like to see a cooling system that can run at thermostat temp, then use a temp that ensures water is burned off on the street. 


Ross, based on my experience water starts burning off long before the thermostat opens.  You can see it with my clear valve covers; they are milky white on start up from water condensation in the engine, but by the time the temp gauge starts moving they have nearly cleared completely.  I've never seen that condensation present when the engine is up to temp, and that's with a 160 degree thermostat.  The condensation will burn off regardless of what thermostat is used, unless the engine is only fired for a very short time.  Burning off condensation is not a consideration when selecting a thermostat.
Jay Brown
- 1969 Mach 1, Drag Week 2005 Winner NA/BB, 511" FE (10.60s @ 129); Drag Week 2007 Runner-Up PA/BB, 490" Supercharged FE (9.35 @ 151)
- 1964 Ford Galaxie, Drag Week 2009 Winner Modified NA (9.50s @ 143), 585" SOHC
- 1969 Shelby Clone, Drag Week 2015 Winner Modified NA (Average 8.98 @ 149), 585" SOHC

   

Stangman

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Re: Cooling temperatures
« Reply #13 on: August 29, 2022, 03:49:24 PM »
Jay who makes your radiator and what fan set up do you have. What are the measurements

jayb

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Re: Cooling temperatures
« Reply #14 on: August 29, 2022, 07:39:45 PM »
On my 68 Mustang with 430 HP 428CJ I'm using a 3 core stock replacement type radiator (top and bottom tanks), with two Spal electric fans.  On my race car with the big 1000 HP SOHC I'm using a 19X31 crossflow aluminum radiator, two 1-1/4" cores, and two larger Spal fans.  Can't remember where I got the radiator but it was about $600.  I will also be using that same fan combo with a different 19X31 crossflow aluminum radiator, dual core with 1" tubes, on my 68 Shelby convertible, with the supercharged FE. I used that same radiator and fan combo on my Galaxie also.  One note about the big aluminum radiators in a Mustang, you have to notch the frame rails at the front to make them fit.  A link to that radiator is below.

https://www.summitracing.com/parts/sum-380431
Jay Brown
- 1969 Mach 1, Drag Week 2005 Winner NA/BB, 511" FE (10.60s @ 129); Drag Week 2007 Runner-Up PA/BB, 490" Supercharged FE (9.35 @ 151)
- 1964 Ford Galaxie, Drag Week 2009 Winner Modified NA (9.50s @ 143), 585" SOHC
- 1969 Shelby Clone, Drag Week 2015 Winner Modified NA (Average 8.98 @ 149), 585" SOHC