Stock fan specs

[JoshMcMadMac]

As an example to my disagreement with proportions, the 4.0L Ranger radiator is larger than the 5.0L Mustang radiator. What does that mean?

 

[shadetree]

The radiator in that example is 1 inch thick...what happens when you multiply a number by 1?

Then to convert square inches (area), you multiply by 1 to get cubic inches(volume)????? Doesn't sound right.shady

 

[JoshMcMadMac]

Then to convert square inches (area), you multiply by 1 to get cubic inches(volume)????? Doesn't sound right.shady

Length x Width x Height is volume, or cubic inches. Square inches (area) is Length x Height in this example, so yes, you multiply the area by the width of one inch to get volume. Math lesson for the day, easily acquired from Google if you like to verify.

 

[engdept]

Then to convert square inches (area), you multiply by 1 to get cubic inches(volume)????? Doesn't sound right.shady

to get square inches, you multiply:
a side x a side

To get the cubic inches you multiply:
a side x a side x the thickness

In the case of the 4.0 1 row radiator, to get square inches you would multiply like this:
17.25"x21.5" = 370.875 sq. in.

In the case of the 4.0 1 row radiator, to get cubic inches you would multiply like this:
17.25"x21.5"x1" = 370.875 cu. in.


That is your math lesson for the day

 

[krugford]

...which really doesn't tell you crap about the radiator, unless your taking into account the row spacing, fin spacing, material, etc, etc.

A radiator is sized based on the required heat rejection of a particular engine. That required heat rejection is related primarily to the power output at any given operating point.

When they designed the cooling system for your Ranger, they knew they would have to get rid of X amount of energy. They have a limited amount of space for a radiator. For a radiator of a given size, you can calculate how much air you need to flow past the radiator to transfer the heat from the coolant to the surrounding ambient. Match the airflow through the radiator at each operating point (whether using mechanical or electric), and you shouldn't have a problem.

Unless you know the CFM rating of your stock mechanical fan across a wide range of operating points, then I doubt you'll be able to properly size an electric fan to do the same job. There are simply too many variables to ask someone else whether it will work or not, unless of course, they live near you, have the same driving habits, have the same vehicle, AND have converted to electric.

 

[MAKG]

Your idea of proportions on engines is silly; just because one engine is of a particular size does not mean that it has a directly proportional cooling necessity as any other engine, especially when you consider that the little 2.2L is putting out the same horsepower as the 4.0L.

Hmm, last I looked, 135 HP was a whole lot less than 210 HP (the SOHC radiator was what was being compared to). For natural aspiration on a street vehicle, the redlines are generally all the same (less than 6000 RPM), and this makes power approximately proportional to displacement. Of course that's an approximation. Dealing with peak power is better, but not by much.

And virtually all engines that haven't been screwed up by guessed mods or bad driving habits (lugging) have the same energy flow. About 1/3 of the energy goes to the crank, 1/3 goes to the radiator and 1/3 goes to the exhaust pipe. THAT'S what tells you to expect radiators in proportion.

 

[Bob Ayers]

Hmm, last I looked, 135 HP was a whole lot less than 210 HP (the SOHC radiator was what was being compared to). For natural aspiration on a street vehicle, the redlines are generally all the same (less than 6000 RPM), and this makes power approximately proportional to displacement. Of course that's an approximation. Dealing with peak power is better, but not by much.

And virtually all engines that haven't been screwed up by guessed mods or bad driving habits (lugging) have the same energy flow. About 1/3 of the energy goes to the crank, 1/3 goes to the radiator and 1/3 goes to the exhaust pipe. THAT'S what tells you to expect radiators in proportion.

Mike, don't forget the differences in towing capacities between the Subaru, and 4.0L Ranger!!!

 

[Bob Ayers]

As an example to my disagreement with proportions, the 4.0L Ranger radiator is larger than the 5.0L Mustang radiator. What does that mean?

The Ranger has a larger towing capacity than the Mustang does!

 

[shadetree]

to get square inches, you multiply:
a side x a side

To get the cubic inches you multiply:
a side x a side x the thickness

In the case of the 4.0 1 row radiator, to get square inches you would multiply like this:
17.25"x21.5" = 370.875 sq. in.

In the case of the 4.0 1 row radiator, to get cubic inches you would multiply like this:
17.25"x21.5"x1" = 370.875 cu. in.


That is your math lesson for the day

Not the same. You are talking about surface area. Radiators have multiple tubes which have more than one side with an interior volume. This would have to be taken into consideration.shady

 

[JoshMcMadMac]

Hmm, last I looked, 135 HP was a whole lot less than 210 HP (the SOHC radiator was what was being compared to). For natural aspiration on a street vehicle, the redlines are generally all the same (less than 6000 RPM), and this makes power approximately proportional to displacement. Of course that's an approximation. Dealing with peak power is better, but not by much.

And virtually all engines that haven't been screwed up by guessed mods or bad driving habits (lugging) have the same energy flow. About 1/3 of the energy goes to the crank, 1/3 goes to the radiator and 1/3 goes to the exhaust pipe. THAT'S what tells you to expect radiators in proportion.

So the Ford Explorer with the 5.0L should not have twice the size of a radiator? But it does!

 

[MAKG]

So the Ford Explorer with the 5.0L should not have twice the size of a radiator? But it does!

No, it doesn't NEED twice the size radiator.

But it sure is convenient if you already have a double-size radiator for the paranoid, to just use it. Too much cooling is very, very minor. Too little is catastrophic. Now, don't be silly about this.

 

[MAKG]

So the Ford Explorer with the 5.0L should not have twice the size of a radiator? But it does!

No, it doesn't NEED twice the size radiator.

But it sure is convenient if you already have a double-size radiator for the paranoid, to just use it. Too much cooling is very, very minor. Too little is catastrophic. Now, don't be silly about this.

 

[JoshMcMadMac]

No, it doesn't NEED twice the size radiator.

But it sure is convenient if you already have a double-size radiator for the paranoid, to just use it. Too much cooling is very, very minor. Too little is catastrophic. Now, don't be silly about this.

How am I being silly? You proclaim that coolant needs is directly proportional to engine size, and now you are digressing from that. What is to say that the Subaru referenced previously needs that much radiator and it is not just for convenience?

 

[Karlton694u]

can you guys please stop? this is getting sad

 

[thegoat4]

The radiator argument is dumb. You guys are trying to infer cooling system capacity from the sheer size/volume of the radiator. Nevermind that those radiators are made of different materials, have different fin counts, are mounted in front of different fans, are behind different condensor cores, are behind different grills, are surrounded by different shrouds, have different coolant flow rates, have different system capacities, are hooked to differnet engines, some are equipped with trans coolers, some with ps coolers, and on and on and on. Too many variables.

Want a meaningful measurement? Find two rangers that are essentially the same, but one has been butchered up with an e-fan. Clean off the radiators and put them both under the same load and see what temp drop you get across the radiators. Lower temp drop==lower cooling capacity.

As for e-fan CFM of air, I don't have numbers, but you can compare them with a rag test. Throw a rag against the front of the radiator, the e-fan vehicle won't pull the rag as hard as the mechanical fan will at driving RPMs.