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keithb7

Cooling System Techie Talk

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My understanding is when engineers created our old Mopar flat head cars, someone spent some time analyzing and designing a cooling system. 

 

They likely would have reviewed fuel burn, engine displacement, heat dissipation exhaust gas volume, and many other factors. Also design and form limitations. Rad size. Core number and Depth. Physical size restrictions based on body design. Material costs. Suppliers. Fan blades. Shroud or not? So many things to consider. 

 

I wonder what their base line standards would gave been? A new car tuned up in great health likely. Clean rad of course. At sea level maybe? I am mainly interested in what ambient temperature did they design the cooling system to keep the engine adequately cool?

 

For example if a system were designed to work at 120 F above ambient, if surrounding air reached 92, that totals 212 F. Water boiling point. 120+92=212. 

 

If a system were rated to 90 F above ambient, theoretically  the surrounding air would reach 122F before water boiling point. 90+122=212. 

 

Add a pressurized rad cap for 7 psi, that increases water boil point to 232F. Add glycol, I think boil point raises further. 

 

I have just been pondering this as ambient temps rise here in the Northern Hemisphere. My 265 was getting warm climbing up 1000ft over 3 or so miles last weekend. At full throttle she holds about 30 Mph as I wind my way up home. 

Never over heated yet. I have good flow and a clean rad. My Windsor never had a fan shroud. At lower speed like I am describing I assume a shroud would be beneficial. I see a few drips glycol once I park it at home. Normal expansion I believe. 

 

Any Chrysler engineers here? Lol. Should I gather up a shroud?

Edited by keithb7

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2 hours ago, keithb7 said:

My understanding is when engineers created our old Mopar flat head cars, someone spent some time analyzing and designing a cooling system

 

They likely would have reviewed fuel burn, engine displacement, heat dissipation exhaust gas volume, and many other factors. Also design and form limitations. Rad size. Core number and Depth. Coolant low rates. Physical size restrictions based on body design. Material costs. Suppliers. Fan blades. Shroud or not? So many things to consider. 

 

I wonder what their base line standards would gave been? A new car tuned up in great health likely. Clean rad of course. At sea level maybe? I am mainly interested in what ambient temperature did they design the cooling system to keep the engine adequately cool?

 

For example if a system were designed to work at 120 F above ambient, if surrounding air reached 92, that totals 212 F. Water boiling point. 120+92=212. 

 

If a system were rated to 90 F above ambient, theoretically  the surrounding air would reach 122F before water boiling point. 90+122=212. 

 

Add a pressurized rad cap for 7 psi, that increases water boil point to 232F. Add glycol, I think boil point raises further. 

 

I have just been pondering this as ambient temps rise here in the Northern Hemisphere. My 265 was getting warm climbing up 1000ft over 3 or so miles last weekend. At full throttle she holds about 30 Mph as I wind my way up home. 

Never over heated yet. I have good flow and a clean rad. My Windsor never had a fan shroud. At lower speed like I am describing I assume a shroud would be beneficial. I see a few drips glycol once I park it at home. Normal expansion I believe. 

 

Any Chrysler engineers here? Lol. Should I gather up a shroud?

Read this and you will discover you are going  to be okay pulling hills and the summer heat. This is of course if all is on good mechanical order.

https://www.allpar.com/cars/desoto/suburban-1951.html

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Wow Keith, I never thought of all the things you mentioned here.  :P

 

I won't pretend I know any of that engineering.  But I do know this.  After my engine rebuild I put in Evans waterless coolant into the Meadowbrook, and I haven't looked back.  Since there's no water in it, it doesn't corrode the radiator and engine.  No need to flush and change it....EVER.  And since the boiling point of this stuff is over 375 degrees (which is much much higher than your normal engine temp), its guaranteed to stay in liquid form, which means superior cooling and no overheating.  It will never turn to steam (well, at least not in our cars LOL).

 

Its been in my car for a year now, and the radiator looks clean, and I've never had any "hot engine" issues.  Does my car's temp increase on a super hot day going uphill?  Yep.  But only to about 195 degrees (up from the normal 180).  Last summer we took it on a long trip when it was 96 degrees (the cowl vent didn't help us much in the cab :lol:)  and went up a long hill, and also got stuck in traffic for an idiotic amount of time...temp never exceeded about 195.  

 

Yes, this stuff costs $45 a gallon, and you risk losing it all if you have a leak, but I don't worry about any of that.  This product has been around for 20 years now, so its been proven.  I'd certainly recommend it.  One thing is for sure, your car is not going to boil over with this stuff in the cooling system.  Might be something you'd want to consider.  :)

 

Oh, btw, my car doesn't have a shroud, either.  I don't remember any Mopar I've ever had having a shroud.  And I've had a couple dozen different cars and trucks over the years.  My big 68 Dodge D-700 (3 ton truck) with an industrial 413 is so well engineered that when its fully warmed up you can grab hold of the valve covers and not get burned (and hang on to them all day if you had to).  The cooling system on that truck is a little different.  Also has sodium filled exhaust valves, and the coolant lines run through the external oil pump to help keep the oil cool. 

 

Anyway, guess I'm done rambling and I got my 2 cents in.  

Edited by Worden18

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In fact, it is not so complicated. Put in radiator and water pump with huge overcapacity, and thermostat will take care of all regimes and conditions at which engine may work. Mopar added special cooling arrangement for exhaust ports, a nice feature. 

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On 5/16/2018 at 12:27 AM, keithb7 said:

My understanding is when engineers created our old Mopar flat head cars, someone spent some time analyzing and designing a cooling system

 

They likely would have reviewed fuel burn, engine displacement, heat dissipation exhaust gas volume, and many other factors. Also design and form limitations. Rad size. Core number and Depth. Physical size restrictions based on body design. Material costs. Suppliers. Fan blades. Shroud or not? So many things to consider. 

 

You think? I wouldn't be at all surprised if they just took what they had been using for the previous five years and bolted that in. If the first few thousand off the line boiled like kettles and the dealers complained, borrow the radiator from a truck and see if that works instead. Then sell it in the following model year as a super new feature.

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I don’t know. The Chrysler engineers of the time have a pretty darn good reputation.  I’d give them the benefit of doubt.  

 

The Ny’r and Imperial had shrouds. Bigger rads too. V8 Vs flat 6. Different fan blades. Etc.  I doubt they just slammed rads in and rolled the dice till they got it right. 

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3 hours ago, keithb7 said:

I don’t know. The Chrysler engineers of the time have a pretty darn good reputation.  I’d give them the benefit of doubt.  

 

The Ny’r and Imperial had shrouds. Bigger rads too. V8 Vs flat 6. Different fan blades. Etc.  I doubt they just slammed rads in and rolled the dice till they got it right. 

I’m sure one of the factors was likely yesteryear’s coolant.  We all know modern oil is much better than what they had in the 50’s.  So the antifreeze probably falls in the same category.  I know the coolant in my car is better than, well, yesterday’s coolant let alone anything from decades ago. 

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Before ethylene glycol was widely used as automobile anti freeze an alcohol based anti freeze was used. As alcohol rapidly evaporates especially when heat is applied the alcohol antifreeze had to be checked and adjusted frequently. I recall going to the garage with my dad every weekend in the early 1950's as he adjusted his anti freeze in his 37 Packard. I would slide down the fenders and play the grill like a banjo. 

 

 

Albert.jpg

 

 

 

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30 minutes ago, Don Coatney said:

Before ethylene glycol was widely used as automobile anti freeze an alcohol based anti freeze was used. As alcohol rapidly evaporates especially when heat is applied the alcohol antifreeze had to be checked and adjusted frequently. I recall going to the garage with my dad every weekend in the early 1950's as he adjusted his anti freeze in his 37 Packard. I would slide down the fenders and play the grill like a banjo. 

 

The "Operator's Manual" for my 1933 Plymouth lists ethylene glycol as an antifreeze in addition to alcohol. That leads me to believe that any use of alcohol after the 1930s was simply because the car's owners were behind the times. Or maybe the alcohol was so cheap compared to ethylene glycol that it was worth the hassle of continuously adding/adjusting the solution each week during winter (many people felt that you had to switch to plain water only during summer).

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