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Ten Rules for Maximum Cooling

Good points made there.
As a kid in the 70s and 80s, I remember seeing cars along the roadside with their hoods up, steam billowing up from the radiator.
Nowadays, I can't recall the last time I saw a car overheat.
The new tech that engines have now would be considered space age in 1975. Plastic intake manifolds? Variable length intake runners, Active exhaust with cutouts, variable cam timing, cylinder deactivation, direct injection....I remember when fuel injection seemed fancy.
 
#41 said:
I have yet to see stats saying that a good factory belt driven fan underperforms electric fans in general. Of course it is dependent on engine rpm.... but do you even NEED 2000-2300 cfm at idle? Mechanical fans move slower at slower rpms, but they also have a helluva relative blade pitch for moving air.

I would love to see some empirical data someday. Until then, mark me down as a tractor fan believer.
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That appears as if I said it. So, for the record, that quote came from Griffin Radiator.
 
451Mopar said:
They didn't mention getting trapped air out of the system.
Electric cooling fans are more efficient freeing up power for the engine, but good electric fans are still expensive.
Many of the aftermarket dual electric fan and shroud modules are over $500
On the otherhand, I still run the old Mopar mechanical viscous clutch fan on the Charger
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Prices on the short fan clutch and a fan are creeping up towards that price. Especially, if you're buying NOS or even a new Mopar licensed fan and clutch.
 
Kern Dog said:
Good points made there.
As a kid in the 70s and 80s, I remember seeing cars along the roadside with their hoods up, steam billowing up from the radiator.
Nowadays, I can't recall the last time I saw a car overheat.
The new tech that engines have now would be considered space age in 1975. Plastic intake manifolds? Variable length intake runners, Active exhaust with cutouts, variable cam timing, cylinder deactivation, direct injection....I remember when fuel injection seemed fancy.
Click to expand...
And the gas stations had tap water or well water for the customer to top off their overheating radiator.
 
Kern Dog said:
Good points made there.
As a kid in the 70s and 80s, I remember seeing cars along the roadside with their hoods up, steam billowing up from the radiator.
Nowadays, I can't recall the last time I saw a car overheat.
The new tech that engines have now would be considered space age in 1975. Plastic intake manifolds? Variable length intake runners, Active exhaust with cutouts, variable cam timing, cylinder deactivation, direct injection....I remember when fuel injection seemed fancy.
Click to expand...
Today they just drive them until they quit then gave them towed.
 
De-mineralised water is normally recommended with coolant concentrate. I presume that is because chemicals [ minerals ] that might be harmful to the engine.....or compromise the chemical composition of the coolant...have been removed.
 
themechanic said:
Prices on the short fan clutch and a fan are creeping up towards that price. Especially, if you're buying NOS or even a new Mopar licensed fan and clutch.
Click to expand...
I noticed the crazy prices the mechanical fans are getting.
 
themechanic said:
I've heard water dissipates heat better than coolant but coolant absorbs heat better. Maybe that's why the factory used a mixture.
Click to expand...
No incorrect. Coolant doesn't absorb heat better.

It's not "coolant" either.

It's Anti-Freeze. It's made to keep the block from freezing, resist rusting, and lubricate the water pump.
 
themechanic said:
Prices on the short fan clutch and a fan are creeping up towards that price. Especially, if you're buying NOS or even a new Mopar licensed fan and clutch.
Click to expand...

Hayden sells an restoration short fan clutch. It's not close to $500.

It doesn't look NOS, but neither does some ill fitting strapped-on zip-tied up aftermarket electric fan.
 
themechanic said:
That appears as if I said it. So, for the record, that quote came from Griffin Radiator.
Click to expand...

Who will happily sell you an electric fan for a profit.

Factory designed electric fans that are tailored to fit a particular radiator, have: info from numerous sensors, controlled by computer logic from said sensors... they do a great job.

The retro setups for our older cars don't have systems like that typically.
 
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All cooling additives will raise the boiling point some. And it will change directly with mixing ratios.... From high school chemistry, ANY solution mixed with water will raise the boiling point and the freezing point.

In the 1930's they used to put straight alcohol in automobile radiators to keep them from freezing. But the alcohol would evaporate over time and those systems were not pressurized or sealed.

Antifreeze at 50% ratio only increases the boiling point 11 degrees.

Your 15 lbs radiator cap increases the boiling point 45 degrees.

Most importantly, the cooling system uses pressure to raise the boiling point of the coolant. Just like the boiling temperature of water is higher in a pressure cooker, the boiling temperature of coolant/water is higher if you pressurize the system. Most cars have a pressure limit of 14 to 15 pounds per square inch (psi). The radiator pressure cap raises the boiling point another 45 F (25 C) so the coolant can withstand the high temperatures. Your radiator cap does a FOUR TIMES more job at increasing your boiling point than antifreeze!

Remember: A good radiator additive does a lot more than just acting as a wetting agent. A good one will provide: anti-corrosion, anti-cavitation, electrolysis resistance, anti acid, lubrication, SCA's (Supplemental Coolant Additives) and thermal conduction... They should remove heat better than antifreeze. Boiling in a pressurized system of water alone is 257 degrees.

The object is to remove heat before going into a boiling situation.

Boiling over is a result AFTER everything else went wrong.
 
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"Boiling over is a result AFTER everything else went wrong."

Maybe not if the boiling over takes place after a quick hot shutdown, which to me would likely indicate the system is on the edge of its cooling limits.
As heat flow takes place over time, and parts of the engine retain a significant amount of heat upon shut off, when the water stops flowing on engine shutoff, and it stagnates on internal hot spots, a potential boil over if very possible if system is already near its limits, by design or use.

Electric water pumps can have a built in delay upon shutoff to help stave off hot engine shutoff boil overs.
 
autoxcuda said:
Who will happily sell you an electric fan for a profit.

Factory designed electric fans that are tailored to fit a particular radiator, have: info from numerous sensors, controlled by computer logic from said sensors... they do a great job.

The retro setups for our older cars don't have systems like that typically.
Click to expand...
Good points.
When I built the Convertible like 20 years ago, I used the Mopar Performance viscous fan package that is now discontinued. I think back when I bought it, is was way less than $100.
I used it for maybe 5,000 miles and when I went to sell it I tried to see what they cost, and the prices were crazy high? Sold it to a friend for maybe $50? and might have thrown in some pulleys. Anyhow, he might be giving me a deal, like almost free, on a bare 400 block.

When I went to the electric fans, I found out many of the controllers were not that good. I ended up using the pricy Dakota Digital controller which can use the factory sending unit. That was the older 4100 version, not the even more expensive $185 one sold now, but has bluetooth: Electronic Fan Controller 70 Amp with Bluetooth Control

Had that wired in the glove box, and also had aftermarket gauges, and an Innovate O2 sensor so wiring was starting to get messy. Going EFI actually cleaned up much of the wiring as the one box and display have all these functions built in. At the time, I didn't intend to go EFI, but ended up there the expensive way replacing all the stuff I started with. If a knew that was where I would end up at, and planned from the start the cost pretty much would have been a wash. I did learn a bunch by doing it twice (or more.)
 
451Mopar said:
Good points.
When I built the Convertible like 20 years ago, I used the Mopar Performance viscous fan package that is now discontinued. I think back when I bought it, is was way less than $100.
I used it for maybe 5,000 miles and when I went to sell it I tried to see what they cost, and the prices were crazy high? Sold it to a friend for maybe $50? and might have thrown in some pulleys. Anyhow, he might be giving me a deal, like almost free, on a bare 400 block.

When I went to the electric fans, I found out many of the controllers were not that good. I ended up using the pricy Dakota Digital controller which can use the factory sending unit. That was the older 4100 version, not the even more expensive $185 one sold now, but has bluetooth: Electronic Fan Controller 70 Amp with Bluetooth Control

Had that wired in the glove box, and also had aftermarket gauges, and an Innovate O2 sensor so wiring was starting to get messy. Going EFI actually cleaned up much of the wiring as the one box and display have all these functions built in. At the time, I didn't intend to go EFI, but ended up there the expensive way replacing all the stuff I started with. If a knew that was where I would end up at, and planned from the start the cost pretty much would have been a wash. I did learn a bunch by doing it twice (or more.)
Click to expand...

I bought a Hayden Jaguar fan clutch and bolted my old Mopar MP fan right to it.

Actually my dumb Champion radiator had the neck too close to center and I had to cut down my MP fan 1" of every blade!! That's a whole 2" smaller diameter. I later had the radiator neck moved, then build the fan shroud still using the 2" smaller diameter fan.

I built a custom very tight fitted sealed fan shroud around it. Cools my 416" stroker motor fine for last 14 years.

How to link here on how I built it: Building a Custom Fan Shroud: Pic by Pic


1755806320163.png
 
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autoxcuda said:
Antifreeze at 50% ratio only increases the boiling point 11 degrees.
Your 15 lbs radiator cap increases the boiling point 45 degrees.
Click to expand...
Here is what I have seen....

Boil.jpg


Your numbers are close to this chart.
The takeaway I see is that the pressure is a greater factor to raising the boiling point than anti-freeze is.
 
Additionally, raising boiling point by adding antifreeze is IMO much like adding ballast to a car to gain traction. You do gain traction at the tire patch, but you now have more weight/mass to haul around, regarding acceleration, braking and cornering that the tire patch has to now contend with. Whereas less antifreeze makes for a more efficient ie a better coolant with ideally less chance of boiling in the first place, and any potential boiling can be controlled as you note by pressure with little downside.
 
Kern Dog said:
Good points made there.
As a kid in the 70s and 80s, I remember seeing cars along the roadside with their hoods up, steam billowing up from the radiator.
Nowadays, I can't recall the last time I saw a car overheat.
The new tech that engines have now would be considered space age in 1975. Plastic intake manifolds? Variable length intake runners, Active exhaust with cutouts, variable cam timing, cylinder deactivation, direct injection....I remember when fuel injection seemed fancy.
Click to expand...
Variable intake runner length- a Mopar first
 
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