Copper/brass Vs Aluminum In Radiators

grumpyvette

Administrator
Staff member
Put A Cap On Your Radiator Problems!!
(found this posted with no author listed)
What makes the better radiator;
THE SECRET to a good solder seal, on a radiator joint, is a totally clean metal (FAIRLY THICK COPPER/ BRASS) surface and the correct solder alloy for the application
many , but not all-aluminum radiators are EPOXY SEALED NOT WELDED,(yes the better versions are welded)
the problem here is that acid dips to clean the surface with alkaloid dips for PH stabilization and raid steam cleaning of metal surfaces followed by use of , lead acid, or silver solder either makes the EPA and OSHA nuts or its darn expensive.
aluminum is an acceptable but not the best quality substitute, as it rapidly metal fatigues and its difficult to weld if corroded
copper is TWICE AS THERMALLY CONDUCTIVE as aluminum

http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html

http://www.caparadiator.com/aluminumvscopper.html
What makes the better radiator;

Aluminum or Copper?



I get asked this question so often that I feel like a broken record telling the pros & cons over and over. I am not a scientist, chemist or engineer but based on my 28 years in the radiator business here is my opinion on which is better; copper or aluminum radiators.



There is much debate over whether a copper or an aluminum radiator will cool better. There are pros and cons to each material. It has been scientifically proven that copper actually transfers heat better than aluminum. It is easier to repair in most cases than aluminum and until the last couple of years was much less expensive. The drawbacks to a copper radiator are the weight difference (aluminum is much lighter) and the solder joints that hold it together. The solder that secures the tubes to the fins does not transfer heat as quickly as copper and slows down the heat transfer. The presence of solder where the tubes are soldered into the headers is also the main cause of what is known as “solder bloom”. I am sure all of you have looked inside a radiator at some time and observed the white residue growing around the tubes. This growth is the result of chemical reactions from different metals (brass tubes, copper header, lead/tin solder) and lime and other chemicals in the water/antifreeze mixture. In the 1990’s some manufacturers started using a process called “Copubraze” which eliminated the solder between the tubes and the headers. The tubes were brazed instead of soldered which prevented the solder bloom problem and also created a better made core. This process was more costly however and most manufacturers were favoring aluminum anyway due to the weight savings. Copper core manufacturers also started using smaller and thinner tubes to break the coolant down into smaller amounts to further improve cooling. Smaller tubes clogged up much easier especially when the vehicles owner did not adhere to recommended cooling system flushing intervals. They also used thinner material to cut weight and improve heat transfer but the longevity suffered.



Aluminum radiators are welded or “aluminum brazed” and the finished piece is 100% aluminum. This eliminates the dissimilar metals and solder bloom problems that affect copper radiators. Aluminum radiators can also use wider tubes that create more surface contact area from the tubes to the fins and helps dissipate the heat quicker. Most aluminum radiators use 1” wide tubes and some manufacturers like Griffin offer 1.25” and 1.5” tubes as well. Traditional copper radiators usually use ½” tubes so a 4 row copper radiator has slightly less fin contact area than a 2 row aluminum core with 1” tubes when you take into account the loss of contact area at the curved ends of the tubes. Most OEM copper radiators were built with the tubes on 9/16” centers from each other. All aluminum cores are built with the tubes on 7/16” or 3/8” centers creating a denser and more efficient core than a standard copper core. I generally tell customers that a high efficiency (tubes on 7/16” or closer centers) copper four row will cool the same as an aluminum core with two rows of 1” tubes. If more cooling is required from the radiator than either of these designs will provide, than an aluminum core with two rows of 1.25” is the thickest recommended for a street application. Any thicker than that and you may have trouble pulling air through the core at low speeds or when at a light.



Aluminum offers the advantage of about 30% to 40% less weight. To a racer this is a huge advantage over copper. Aluminum can also be polished out to a mirror like finish for those concerned with show appearance. Neither has an advantage when it comes to corrosion. Left unprotected, a copper radiator core will turn green and deteriorate rapidly especially in a damp environment. That is why copper radiators have always been painted, usually black. Aluminum will oxidize if not protected from the elements.



If your radiator needs to be replaced and you want to retain as much originality as possible then recoring your original copper radiator may be the best choice for you. A copper radiator core can be made more efficient by changing the tube spacing and fin count. As I stated earlier the radiators that were made from the 1950’s to the 1970’s generally used ½” wide tubes placed on 9/16” centers from each other. If you counted the fins you might get as few as 6 or 8 fins per inch (FPI). If the tubes are placed closer together and the fins are packed in tighter a denser core is created that throws off much more heat. A high efficiency core can have tubes on 7/16”, 3/8” or even 5/16” centers and fin counts increased to 12 to 14 FPI. That may not seem like a big deal but the surface area is greatly increased. As an example; a 26” wide radiator core with tubes on 9/16” centers has about 45 tubes from side to side. A high efficiency core of the same width has 57 tubes from side to side. Combined with all the additional fins between the tubes this provides approximately 25% to 30% better cooling than the OEM radiator had. A three row high efficiency core will cool about the same as a regular four row without taking away another 5/8” of fan clearance. Going to a thicker core will cool better but there is one big thing to remember. As the air passes through each row of tubes it is picking up heat along the way. The air cools off each following row of tubes a little less than the previous rows. A four row core is of course better than a two row core but increasing a cores thickness does not necessarily mean it will continue to get more efficient as it gets thicker. As I said earlier a core that is too thick will also impede the airflow at low speeds.



So which is better, aluminum or copper? My opinion is neither. Each one has advantages over the other in different areas. The decision over which to use in your particular case comes down to what is more important to you. Weight, appearance, originality and cost all need to be considered before you make your decision. From my own experience on my own vehicles I have found that a properly built high efficiency copper radiator will cool the same as a well made aluminum radiator. Like I said at the beginning, I am not a scientist or an engineer but this is my opinion and I’m stickin’ to it.



READ THIS ALSO

viewtopic.php?f=57&t=853

http://www.carid.com/dorman/radiator-fan-assembly.html

Aluminum or Copper?

I get asked this question so often that I feel like a broken record telling the pros & cons over and over. I am not a scientist, chemist or engineer but based on my 28 years in the radiator business here is my opinion on which is better; copper or aluminum radiators.

first lets start with RADIATOR SIZE,
You should try to use a ABSOLUTE MINIMUM, of 1 square inch of radiator core frontal surface area for every CID and 1.5 -2 SQ inches, PER CUBIC INCH OF DISPLACEMENT is better, keep in mind a larger size coolant tube has a greater surface area to allow heat transfer and a higher fin count per inch helps heat transfer rates, large tube aluminum radiator is far more efficient that a stock 2-3 tube design, a so for a 350 CID engine thats 350-525 sq inches of radiator surface area,is ideal, obviously space to mount the radiator is limited but you can usually mount a thicker core with multi rows of coolant tubes and a higher fin count and more effective fans and fan shrouds, to increase the heat transfer rates, a 540 big block would obviously produce more heat and require a larger radiator surface area. BE AWARE that a properly installed OIL cooler , high capacity baffled oil pan and /or transmission fluid cooler, if your running an automatic transmission, helps reduce the total heat load on the radiator



https://www.cgj.com/2013/07/02/aluminum ... ptibility/


There is much debate over whether a copper or an aluminum radiator will cool better. There are pros and cons to each material. It has been scientifically proven that copper actually transfers heat better than aluminum. It is easier to repair in most cases than aluminum and until the last couple of years was much less expensive. The drawbacks to a copper radiator are the weight difference (aluminum is much lighter) and the solder joints that hold it together. The solder that secures the tubes to the fins does not transfer heat as quickly as copper and slows down the heat transfer. The presence of solder where the tubes are soldered into the headers is also the main cause of what is known as solder bloom . I am sure all of you have looked inside a radiator at some time and observed the white residue growing around the tubes. This growth is the result of chemical reactions from different metals (brass tubes, copper header, lead/tin solder) and lime and other chemicals in the water/antifreeze mixture. In the 1990 s some manufacturers started using a process called Copubraze which eliminated the solder between the tubes and the headers. The tubes were brazed instead of soldered which prevented the solder bloom problem and also created a better made core. This process was more costly however and most manufacturers were favoring aluminum anyway due to the weight savings. Copper core manufacturers also started using smaller and thinner tubes to break the coolant down into smaller amounts to further improve cooling. Smaller tubes clogged up much easier especially when the vehicles owner did not adhere to recommended cooling system flushing intervals. They also used thinner material to cut weight and improve heat transfer but the longevity suffered.

tube_sizex.jpg


Aluminum radiators are welded or aluminum brazed and the finished piece is 100% aluminum. This eliminates the dissimilar metals and solder bloom problems that affect copper radiators. Aluminum radiators can also use wider tubes that create more surface contact area from the tubes to the fins and helps dissipate the heat quicker. Most aluminum radiators use 1 wide tubes and some manufacturers like Griffin offer 1.25 and 1.5 tubes as well. Traditional copper radiators usually use tubes so a 4 row copper radiator has slightly less fin contact area than a 2 row aluminum core with 1 tubes when you take into account the loss of contact area at the curved ends of the tubes. Most OEM copper radiators were built with the tubes on 9/16 centers from each other. All aluminum cores are built with the tubes on 7/16 or 3/8 centers creating a denser and more efficient core than a standard copper core. I generally tell customers that a high efficiency (tubes on 7/16 or closer centers) copper four row will cool the same as an aluminum core with two rows of 1 tubes. If more cooling is required from the radiator than either of these designs will provide, than an aluminum core with two rows of 1.25 is the thickest recommended for a street application. Any thicker than that and you may have trouble pulling air through the core at low speeds or when at a light.

http://garage.grumpysperformance.com/index.php?threads/replacing-a-early-c4-corvette-radiator.15833/

Aluminum offers the advantage of about 30% to 40% less weight. To a racer this is a huge advantage over copper. Aluminum can also be polished out to a mirror like finish for those concerned with show appearance. Neither has an advantage when it comes to corrosion. Left unprotected, a copper radiator core will turn green and deteriorate rapidly especially in a damp environment. That is why copper radiators have always been painted, usually black. Aluminum will oxidize if not protected from the elements.



If your radiator needs to be replaced and you want to retain as much originality as possible then recording your original copper radiator may be the best choice for you. A copper radiator core can be made more efficient by changing the tube spacing and fin count. As I stated earlier the radiators that were made from the 1950 s to the 1970 s generally used wide tubes placed on 9/16 centers from each other. If you counted the fins you might get as few as 6 or 8 fins per inch (FPI). If the tubes are placed closer together and the fins are packed in tighter a denser core is created that throws off much more heat. A high efficiency core can have tubes on 7/16 , 3/8 or even 5/16 centers and fin counts increased to 12 to 14 FPI. That may not seem like a big deal but the surface area is greatly increased. As an example; a 26 wide radiator core with tubes on 9/16 centers has about 45 tubes from side to side. A high efficiency core of the same width has 57 tubes from side to side. Combined with all the additional fins between the tubes this provides approximately 25% to 30% better cooling than the OEM radiator had. A three row high efficiency core will cool about the same as a regular four row without taking away another 5/8, of fan clearance. Going to a thicker core will cool better but there is one big thing to remember. As the air passes through each row of tubes it is picking up heat along the way. The air cools off each following row of tubes a little less than the previous rows. A four row core is of course better than a two row core but increasing a cores thickness does not necessarily mean it will continue to get more efficient as it gets thicker. As I said earlier a core that is too thick will also impede the airflow at low speeds.



So which is better, aluminum or copper? My opinion is neither. Each one has advantages over the other in different areas. The decision over which to use in your particular case comes down to what is more important to you. Weight, appearance, originality and cost all need to be considered before you make your decision. From my own experience on my own vehicles I have found that a properly built high efficiency copper radiator will cool the same as a well made aluminum radiator. Like I said at the beginning, I am not a scientist or an engineer but this is my opinion and I,m stickin, to it.



BTW, if youve got an aluminum radiator to repair... watch this video

http://www.muggyweld.com/1clip3.html
the value depends on the ratio of COST to quality and expected life span, the BETTER QUALITY aluminum 3 & 4 tube aluminum radiators do a very effective job at heat transfer and in my opinion are well worth the cost. but be aware youll need to install anodes and run a 50% antifreeze coolant mix to get the max life span on the aluminum radiator


you should read these links
 
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Obviously construction differs between different manufacturers, and both the internal tube size and number of fins per square inch effect heat transfer rates, generally a three row radiator provides a larger surface area to allow heat transfer to the airflow, than a two row, design, and a slightly larger fluid volume and slower internal flow rate allowing the hot coolant more time to dissipate heat on its trip thru the radiator, and if you really need to cool an engine a four row aluminum design with the proper fans and air duct work might be required, but radiator design and fin count per inch vary so shop carefully

http://garage.grumpysperformance.com/index.php?threads/aluminum-radiator-sources.755/

as a general rule the 3 & 4 row designs tend to cool better because a higher percentage of coolant is in direct contact with the internal aluminum tubes surface and that makes transfer of the heat to the fins that dissipate the heat more efficient,and don,t forget an efficient fan and shroud are critical to cooling but not all radiator cores are even close to equal, theres a huge variation in quality and some designs are far superior

tube_sizex.jpg

Stewart Components Tech Tips
Tech Tip #5 - Radiators & External Plumbing

Radiators
Thicker radiators do have slightly more airflow resistance than thinner radiators but the difference is minimal. A 4" radiator has only approximately 10% more airflow resistance than a 2" radiator.

In past years, hot rodders and racers would sometimes install a thicker radiator and actually notice decreased cooling. They erroneously came to the conclusion that the air could not flow adequately through the thick radiator, and therefore became fully heat-saturated before exiting the rear of the radiator core. The actual explanation for the decreased cooling was not the air flow, but the coolant flow. The older radiators used the narrow tube design with larger cross section. Coolant must flow through a radiator tube at a velocity adequate to create turbulence.

The turbulence allows the water in the center of the tube to be forced against the outside of the tube, which allows for better thermal transfer between the coolant and the tube surface. The coolant velocity actually decreases, and subsequently its ability to create the required turbulence, in direct relation to the increase in thickness. If the thickness of the core is doubled, the coolant velocity is halved. Modern radiators, using wide tubes and less cross section area, require less velocity to achieve optimum thermal transfer. The older radiators benefited from baffling inside the tanks and forcing the coolant through a serpentine configuration. This increased velocity and thus the required turbulence was restored.

Radiators with a higher number of fins will cool better than a comparable radiator with less fins, assuming it is clean. However, a higher fin count is very difficult to keep clean. Determining the best compromise depends on the actual conditions of operation.

Double pass radiators require 16x more pressure to flow the same volume of coolant through them, as compared to a single pass radiator. Triple pass radiators require 64x more pressure to maintain the same volume. Automotive water pumps are a centrifugal design, not positive displacement, so with a double pass radiator, the pressure is doubled and flow is reduced by approximately 33%. Modern radiator designs, using wide/thin cross sections tubes, seldom benefit from multiple pass configurations. The decrease in flow caused by multiple passes offsets any benefits of a high-flow water pump.

Gross flow radiators are superior to upright radiators because the radiator cap is positioned on the low pressure (suction) side of the system. This prevents the pressure created by a high-flow water pump from forcing coolant past the radiator cap at high RPM. As mentioned in the radiator cap section, an upright radiator should be equipped with radiator cap with the highest pressure rating recommended by the manufacturer. The system will still force coolant past the cap at sustained high RPM.


External Plumbing
Street-driven vehicles seldom need auxiliary plumbing or coolant lines. SBC race engines with aluminum cylinder heads usually require extensive external plumbing to address two design problems:


1. Aluminum heads have much smaller water jackets than cast-iron heads because the external dimensions are similar, but the ports are usually larger, the deck is thicker, and the material near the rocker stands is thicker, all leaving less area in the water jackets. This decreased internal area leaves less area in the water jackets.
2. The siamese center exhaust ports are a design compromise that presents additional problems when aluminum heads are used. The area near the center exhaust valves is thicker, thus allowing providing less surface area for cooling.

We recommend installing a pair of -10 AN lines that connect the rear of the aluminum cylinder heads to the thermostat housing crossover in the front. This step will help offset the smaller water jackets. A pair of -10AN lines connecting the pressure side of the water pump with the area in the center of the cylinder head (just below the exhaust ports) will offset the lack of surface area due to the extra material.
 

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http://intermountainradiator.blogspot.c ... lable.html

shop%2001-19-2011%20029.JPG

btw any time you run a mix of aluminum, cast iron and or brass in a cars cooling system,
you NEED to run an ANODE OR SEVERAL ANODES in your cooling system AND US A 50% antifreeze coolant or youll have corrosion issues

https://www.wildhorses4x4.com/produ...MI8tOx3-a26AIVSl8NCh0rLwqBEAQYAiABEgJ7-fD_BwE
16543_13035_popup.jpg


https://www.summitracing.com/parts/...MI8tOx3-a26AIVSl8NCh0rLwqBEAQYASABEgLrpPD_BwE


https://www.flex-a-lite.com/accessories/radiator-accessories/radiator-anode.html

flx-32060_wu_ml.jpg



anodea.png

http://garage.grumpysperformance.com/index.php?threads/anodes.74/#post-4127

coolantq.jpg

tube2.jpg

tubes1.jpg


Do you know how to choose the right radiator for your car, truck, heavy equipment ? There are many options when choosing the right radiator to cool your application. Having a freind in the radiator business that knows what they are doing is key. In this post I will explain what a MX style core is and why its better than the average off the shelf radiator.
The above photo shows two radiators side by side one is a four row and the other is a three row. Do you know which one will cool better? If you guessed the four row you would be very mistaken. The three row pictured will cool 30-40% better than the four row. Why is that? Well things to consider in the equation are size of tubes, fin count, tube spacing, fin construction.

In the above picture the core on the right is the MX high performance radiator core. Look at how many tubes there are in comparison to the standard core on the right, there are 4.5 tubes on the right core per every 2 inches verses 6 tubes on the left. This means more tubes to carry more fluid.


Here is the MX radiator core on the right notice the tubes are wider 5/8 inch verses 1/2 inch and there are more of them closer together than the standard core. Wider tubes means more surface area of the liquid is being cooled.

shop%2001-19-2011%20026.JPG

Next variant is fins per inch, the standard core usualy has 12 fins per inch, where the MX core has as many as 16 fins per inch.
So the heat from your engine is transferred by the liquid in your cooling system to the radiator through the tubes, to the fins and away from the radiator by moving air across the fins. More and bigger tubes, better fin count and tube spacing all play a role in how a radiator transfers heat.
There are many other types of radiator cores and construction types that are made for specific applications. A earth mover has a different core than a conventional automobile and so does a large over the road truck. Picking a good radiator shop with a knowledgeable staff can help you cool off your vehicle. Call an expert for advise when it comes to cooling systems. We are here to help and love to answer your questions.
http://www.intermountainradiator.com
 
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95blklt1
posted this bit of info

HERES a Dewitt aluminum rad and wow is it a lot thicker! Here is the old:
Photo0262.jpg

And the new:
Photo0261.jpg




it should be obvious the DEWITT ALUMINUM radiator provides far more heat transfer surface area, Theres several well known sources for quality aluminum radiators and just as obviously theres clearance and space issues to consider.
most big blocks used in engine swaps produce a good deal more power than a stock SBC and burn a good deal more fuel, this results in a good deal more heat thats generated that needs to be transferred efficiently to outside air flow,the engines power generating extra power seems to always require a larger size radiator , now obviously without knowing the radiators fluid capacity,surface area and air and coolant flow rates I can,t tell if your radiator is fully up to the task at hand, but the symptoms that are usually described, of the engine heat building rapidly if the cars not moving tend to point to a need for a higher air flow rate thru the radiator.
I generally use 3 core 1.5 inch tube designs , but theres a good many factors involved, and adding a 200 amp alternator or a more efficient fan and adding an additional oil or trans cooler could very easily make a huge difference, as it lowers the heat loads on the cooling system

http://garage.grumpysperformance.co...ing-system-flow-rates-and-heat-transfer.9880/



https://www.hotrod.com/articles/ccrp-0211-aluminum-or-copper-radiator-for-your-car/

Aluminum or Copper Radiator for Your Car - Radiators:Aluminum or Copper?

Matt KingphotographerTony Nausiedawriter
Aug 11, 2009


When you're planning out the stages of your car buildup, the cooling system probably isn't a particularly thrilling part of the investment. So if you're in the market for a new radiator, you've probably noticed that there are a myriad of models available to fit your car. Will a two-row aluminum work as well as a four-core copper-brass radiator? Which material cools better, and why? We spoke with the folks at Griffin Radiators, who deconstructed the marketing hype and broke down a little cooling science for your benefit (as well as ours).


Just like your engine, a radiator needs air to function. It's a water-to-air heat exchanger, so it requires air to flow past a sufficiently large network of tubes that contain flowing engine coolant. The tubes make contact with thin metal fins to further increase the surface area available for cooling. Of course, more surface area means that more of the coolant's heat can be dissipated. The ideal radiator, then, would be built from highly conductive metal with large diameter tubes and maximum tube-to-fin contact, and it would be able to pass air efficiently with minimal restriction. Copper-brass conducts heat considerably better than aluminum does. Bigger tubes and more fins increase surface area. So why don't we build a five-core copper-brass radiator with huge tubes and a bunch of cooling fins? The limitations are material strength, weight, and airflow.

Copper-brass alloy isn't as strong as aluminum, so its tubes are more susceptible to blowing out under even the relatively mild pressure generated by a cooling system. Building a copper-brass radiator with a larger, more efficient 1-inch tube diameter requires thickening the tube wall to 0.015 inch-twice as thick as is necessary on a 51/48-inch-diameter tube. That means the larger tubes weigh over three times as much as the smaller tubes-not good! The compromise comes from building the tubes out of aluminum. An aluminum radiator using 1-inch-wide tubes with 0.016-inch wall thickness is 60 percent lighter than the same copper-brass radiator. The 1-inch-wide tubes increase tube-to-fin contact and cooling capacity by roughly 25 percent over a radiator built with 11/42-inch tubes. The net result? Griffin claims that a two-row aluminum radiator with 1-inch tubes will cool as well as a five-row copper-brass radiator with 11/42-inch tubes. That frees up some extra room under the hood, and the two-row design allows less restricted airflow through the core. More air equals more cooling.


Sure, the theory works, but is it enough to justify shelving your stock copper-brass radiator for a slick, shiny aluminum piece? We've certainly been able to cool our big-blocks just fine using a stock-appearing four-core copper-brass radiator like U.S. Radiator's Desert Cooler. In fact, our U.S. Radiator-cooled 455ci Pontiac has yet to eclipse 200 degrees F. Would the Pontiac run any cooler with a trick aluminum radiator? Griffin feels that a well-designed aluminum radiator cools better. These days, aluminum radiators are the trend in the aftermarket as well as in OEM production. But it's hard to say how much better an aluminum radiator will cool a unique car. Griffin explained that aluminum radiators do have more distinct advantages in racing, where damage resistance and ultra-high-pressure cooling systems are commonplace. They can handle a 30-psi pressurized cooling system, and a special high-temperature epoxy reinforcement process provides additional strength to the welded tubes. That's a bit much to ask from a soldered copper-brass radiator.


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Custom-fit aluminum radiators are still pretty steeply priced, but universal-fit aluminum racing radiators are very competitive with copper-brass replacements. Griffin's racing radiators are MIG-welded, and while they don't look as nice as the company's TIG'd custom-fit radiators, they should function just as well provided you're up to a little fabrication work to install them. The real penalty is a paltry 30-day warranty, compared to the two-year guarantee on all Griffin's custom-fit radiators. Provided there are good engine-to-frame grounds to prevent electrolysis, and assuming you change your coolant every year, Griffin says either model should keep you cool for years.


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So what should you take from this? If you're beating the living daylights out of your car, whether it's in the form of a 140-mph blast on the Silver State Challenge or a 7,000-rpm downshift before turn five of Elkhart Lake Raceway, you may need to exploit the high-coolant-pressure handling and vibration-fatigue resistance of a stout aluminum radiator. But whether you like the high-tech look of aluminum or the resto/sleeper stealth of copper-brass, either (when properly selected) should be able to cool your street car, provided it's coupled with a good fan and shroud.


Summit's universal-fit 2531/44-inch-wide by 19-inch-tall aluminum radiator (PN 380325) was practically a drop-in replacement in our '71 Chevy Nova. Although the dimensions were identical to the stock copper-brass two-core, a little fab work was needed to properly mount it in the cradle. We fabricated two 11/48-inch-thick aluminum mounting straps to secure the top of the radiator to the core support-plenty secure.


 
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http://www.enginebasics.com/Engine%20Ba ... 20Pg5.html

Radiator Fins

Increasing the radiator fin count, or number of fins per inch, provides more surface area for the transfer of heat to the cooling air. However, increasing the fin count increases the restriction of the radiator to cooling airflow. Lower cooling airflows result in lower heat transfer. In every installation there is an optimum combination of fin performance and core restriction that will produce maximum heat transfer. Increasing the core restriction from this optimum point by increasing fin count will reduce the heat transfer performance of the radiator. On the other hand, if the original radiator has a very low fin count, increasing will improve heat transfer. In general, for high performance applications, fin counts from 12 fins per inch to 16 fins per inch are optimum. Increasing the fin count above 16 fins per inch will almost always result in reduced heat transfer performance. Since, as we have seen, in a given installation under “steady-state” conditions the radiator must transfer the given heat load no matter what, the reduced heat transfer performance resulting from an excessively restrictive high fin count must be compensated for by increased coolant temperature, possibly to the point of overheating.

Radiators may be made with plate fins. In this case, the tubes are inserted through stacks of relatively flat fins that have tube holes in them. The tube holes in the fins have collars on them which help to provide the solder or braze bond between the fins and tubes. These collars tend to limit the fin spacing to a maximum of about 13 fins per inch.

Radiators may also be made with serpentine fins. In this case, rows of tube are stacked with layers of corrugated fins. The fins become bonded to the tubes where the tips of the fin convolutions touch the tubes during solder baking or brazing. Soldered plate fin radiators are usually structurally stronger that soldered serpentine radiators and are more expensive to manufacture. Brazed serpentine radiators are usually stronger structurally that nay soldered radiator.

Radiator fins, whether plated or serpentine types, may be louvered or non-louvered. Louvered fins turbulate the air passing through the radiator to increase the “scrubbing action” of the cooling air, providing greatly improved heat transfer with some increase in air restriction. Louvered fins also tend to become clogged with dust and debris more readily than non-louvered fins, but for high performance applications are the only way to go. Non-louvered fins are typically used on farm and construction equipment, operating in dirty environments. Non-louvered fins may be made with patterns of dimples, waves, or bumps in order to provide turbulation without clogging.
Core Depth and Number of Rows of Tubes

-IMPROVEMENT RULE- #4 Increasing the fin count may help, but it may hurt. Increasing the count above 16 fins per inch will almost always hurt.

-IMPROVEMENT RULE- #5 A plate fin radiator and a serpentine fin radiator of the same fin count, tube size, tube rows, face area, core depth, etc., will have the same heat transfer performance. However, serpentine fin radiators can be made with higher fin counts, sometimes resulting in improved performance.

-IMPROVEMENT RULE-#6 Louvered fins provide greatly improved heat transfer with some increase in cooling air restriction. Changing from a non-louvered radiator to a louvered radiator core almost always improves heat transfer performance.
As we have discussed, cooling air becomes warmer as it travels through the radiator core. Each successive row of tubes becomes cooled by warmer and warmer cooling air until at some point little or no heat transfer takes place. As was discussed regarding fin count, in every installation there is an optimum combination of fan performance and core restriction that will produce maximum heat transfer performance. Increasing the core restriction from this point by increasing the number of rows of tubes will reduce the heat transfer performance of the radiator. However, if there is a high rate of cooling airflow through the core, adding a row of tubes will probably provide some improvement. In high performance applications with louvered fins, three rows or a maximum of four rows will probably provide best performance. Increasing beyond four rows in a louvered core will provide little or no improvement and may even result in reduced performance.

Adding another row of tubes has other effects. It provides another path for the coolant, resulting in lower coolant flow velocities through the tubes. Optimum coolant flow velocity through the radiator tubes is about 6 to 8 feet per second. If the flow rate becomes low enough, laminar flow occurs, creating a boundary layer of coolant along the walls of the tubes. This boundary layer, or very slowly moving layer of coolant, acts as an insulator and retards heat transfer. Going to a smaller tube size when adding a row of tubes is one way to keep the coolant flow rates up in the tubes to help prevent the formation of a boundary layer. Another way is to use dimpled tubes, which are commonly used in low flow applications.

Contrary to popular opinion, dimpled tubes do not slow the coolant down in order to make it stay in the tubes longer. The dimples increase the length of the coolant flow path by making the coolant twist and turn as it passes through the tube. This actually speeds up the coolant flow along the tube wall, increasing its “scrubbing action,” preventing the formation of a boundary layer, and improving heat transfer. On the other hand, using dimpled tubes when they are not needed can hurt heat transfer performance by increasing tube restriction, which reduces coolant flow and can cause cavitation at the coolant pump.

-IMPROVEMENT RULE- #7 Adding a row of tubes may help, but it may hurt by increasing cooling air restriction and reducing the coolant flow rate in the tubes. If the cooling airflow has been increased over the original installation, adding a row or two will probably help in this situation. Increasing the number of rows beyond 4 in a louvered fin core will almost always hurt.

-IMPROVEMENT RULE- #8 Adding two rows of tubes without increasing the coolant flow rate (Bigger pump or turning the old pump faster) will probably reduce performance because of low coolant flow rate in the tubes. Reducing the tube size or going to dimple tubes may help. Increasing the coolant flow rate will surely help.
 
Coolant Selection

Water has a higher specific heat than an ethylene glycol or propylene glycol coolant mix. Therefore, it provides the best heat transfer performance in a cooling system. If a cooling system is marginal, that is, it only overheats on the hottest of days, then running with water as a coolant in the summer and an ethylene glycol or propylene glycol coolant solution during the rest of the year will probably solve the problem. Commercial coolant solutions provide cooling, anti-freeze protection, corrosion inhibitors to protect the metals in the cooling system, and a lubricant for the water pump. When running water as a coolant for maximum heat transfer, a product that provides a corrosion inhibitor and water pump lubricant should be added to the water.

In terms of the relative heat transfer performance of ethylene glycol versus propylene glycol coolant bases, they are pretty much equal when mixes according to the manufacturers’ recommendations, usually a 50/50 water to glycol mix. Ethylene glycol coolant solutions provide slightly higher heat transfer performance over propylene glycol solutions at low coolant flow rates.

-IMPROVEMENT RULE- #9 For maximum heat transfer performance in warm climates, use water as a coolant with an additive to provide a corrosion inhibitor and water pump lubricant.For winter service, use a 50/50 water to ethylene glycol coolant solution that includes corrosion inhibitors and a pump lubricant.
Aluminum vs. Copper/Brass Radiators

Copper is a better conductor of heat than aluminum. Copper/brass radiators usually have copper fins, but brass tubes (70% copper, 30% zinc). The bond between the fins and the tubes may be made with soldier (A tin/lead alloy, or high-tin alloy) or with a braze material (mostly copper).
Engine Cooling
9 Rules for Improving Engine Cooling System Capability in High-Performance Automobiles

Produced by the National Automotive Radiator Association (NARSA) and by Richard F. Crook, Transpro, Inc.

It’s not unusual for automobile enthusiasts to want to increase the power of the engine in their automobiles and many aftermarket options are available to them to accomplish this. Increasing the engine horsepower then presents the problem of making sure that other components of the vehicle, such as the drive train and the cooling system, can handle the increased engine power.

Small increases in engine power can usually be accommodated by the original drive train and cooling system, since there is usually some safety factor designed in and because the vehicle will not always be driven under the worst conditions or highest temperatures, Larger increases in engine power may require modifications to improve the performance of the other vehicle systems, particularly the cooling system.

There are actually many popular misconceptions regarding the heat transfer performance of an engine cooling radiator. Because many of the more common of these misunderstandings may actually reduce cooling performance rather than improve it, some clarification is required.
Effect on the Cooling System of Increasing Engine Horsepower

It’s helpful to understand that, during operation, internal combustion engines convert the energy of fuel into mechanical work and heat. Approximately one-third of the fuel energy goes into the mechanical work of the moving vehicle, one-third into exhaust heat, and one-third into heat transferred by the engine cooling system to the ambient air.

Coolant Performance

This means that heat load to the cooling system at rated power (Usually expressed in BTUs per minute) is approximately equal to the rated power of the engine expressed in BTUs per minute (HP X 42.4 = BTU/minute). From this we can see that if an engine is modified to increase its horsepower, the load to the cooling system will also increase. In fact, the heat load to the cooling system will increase by about the same percentage as the increase in engine horsepower. So, if we increase the engine horsepower by 20 percent, we can expect an increase of about 20 percent in the heat load to the cooling system.

The Major Factor Governing Cooling System Heat Transfer

Cooling system heat transfer is governed by a single major factor-the heat load to the cooling system. Under “steady-state” conditions, the heat load to the cooling system (the heat rejected by the engine to the cooling system) will be transferred to the cooling air by the radiator no matter how good or how poor the radiator. So, if both a “poor” radiator and a “good” radiator will both transfer the same heat load to the cooling air, how can we say that one radiator has better heat transfer performance than the other? The answer is that, under “steady-state” conditions, with a “good” radiator in the cooling system, the radiator inlet temperature (Radiator top tank temperature) will stabilize at a lower temperature than a “poor radiator” in place. The “poor radiator may be so poor that its coolant temperature may rise to the boiling point resulting in engine overheating.

Coolant Performance
Temperature Differential

The difference between the radiator average core temperature and the temperature of the cooling air is the driving force behind the transfer of heat from the coolant to the cooling air. When an engine starts and is run up to rated load, the coolant begins to heat up. When there is no thermostat in the system, the coolant flows from the engine through the radiator and back to the engine. Initially, the coolant and metal in the engine absorb the heat being produced and continue to do so until the temperature of these parts exceeds the cooling air temperature. At this point, heat transfer to the cooling air commences. The coolant temperature continues to rise until it reaches a temperature at which the difference between the radiator average core temperature and the incoming cooling air is great enough to transfer the entire heat load to the air. This then becomes a “steady-state” condition.

Heat Load to the Cooling System

The heat load to the cooling system is related to the flow through the radiator and the temperature drop through the radiator by the following expression:

Q = M * cp *dT

Where Q is the heat load BTU/min., M is the mass flow rate of the coolant in BTU per pound per degree F, dT is the temperature drop through the radiator in degrees F, and * indicates multiplication. Since a gallon of coolant weighs about 8.3 pounds, we can replace M in the expression by 8.3 times the coolant flow in gallons per minute, or GPM. The resulting expression is as follows:

Q = 8.3 * GPM * cp * dT

Since the specific heat of the coolant is essentially constant and the coolant flow rate
 
Effects of Radiator Design on the Cooling System

A cooling system whose heat load and coolant flow rate results in a 10 degree F coolant temperature drop through the radiator will have that same coolant temperature drop w

hether the radiator has a very small face area and flat fins or a very large face area and louvered fins. The difference is that the large louvered fin radiator will be more effective than the small radiator at transferring heat to the cooling air, meaning that it can do it with a much lower difference in temperature between the core and cooling air. The small radiator may require such a high difference in temperature between the core and the cooling air and the core that the coolant may reach boiling temperature before the core is able to transfer all of the heat load to the cooling air. While both radiators would have the same coolant temperature drop through the radiator, we would say that the larger radiator had better heat transfer performance if its top tank temperature (Inlet coolant temperature) stabilized at, say, 180 degrees F while the smaller radiator stabilized at 220 degrees F.

Coolant Flow Rate

Looking at the previous expression, we can see that slowing the coolant down is the wrong way to go. If the heat load is constant, lowering the flow will increase the temperature drop through the radiator, making the bottom tank, or radiator outlet, temperature less than before. If the bottom tank temperature goes down, the top tank temperature must go up to maintain approximately the same average core temperature so that the heat load may be transferred to the cooling air. At the reduced power setting it would rise above 190 degrees F and at 240 hp the engine would be overheating worse than before. In fact, because the lower flow rate results in lower coolant velocity and less “scrubbing action” in the tubes, the average coolant temperature must rise slightly in order to transfer the heat load from the coolant to the cooling air, making matters even worse.

What would happen if we increase the coolant flow? Will it go through the radiator so fast that there won’t be time for cooling to take place? Not at all, from the expression, we can see that if the heat load is constant, increasing the coolant flow rate will reduce the coolant temperature drop through the radiator, resulting in a higher bottom tank temperature. If the bottom tank temperature is increased, the top tank temperature must go down to maintain approximately the same average core temperature. This is what we were hoping to achieve. With the top tank temperature now less that 190 degrees F at the reduced power point, we can expect that the system will be better able to run at 240 hp without overheating, In fact, because the increased coolant flow rate results in a higher coolant flow velocity and better “scrubbing action” in the tubes, the average coolant temperature decreases slightly while transferring the same heat load to the cooling air, further lowering the top tank temperature, resulting in better cooling performance.

From this we see that increasing the coolant flow rate will result in better heat transfer performance.There are some cautions to be observed in increasing coolant flow rate, however. Going too far may result in aeration and foaming of the coolant, possible damage to the radiator by overpressure, cavitation of the pump, due to excessive pressure drop through the radiator, and erosion of the radiator tubes. The ideal coolant flow rate is one that will provide optimum coolant flow velocity through the radiator tubes in the range of 6 to 8 feet per second. Flow velocities above 10 feet per second should be avoided.

- IMPROVEMENT RULE # 1 -Anything you can do to increase the coolant flow rate, within limits described, will improve heat transfer and cooling performance. Anything you do to restrict or reduce the coolant flow rate will hurt cooling performance

Cooling Airflow

Cooling air becomes heated as it passes through the radiator. It enters the radiator at ambient temperature and exits the radiator at some increased temperature. It is the difference between the average core, or coolant temperature and the average of these two cooling air temperatures that creates the ability of the radiator to transfer heat to the air. The slower the air passes through the radiator, the higher will be its exit temperature and the higher will be the average cooling air temperature. The higher the average cooling air temperature, the less heat will be transferred from the coolant to the air. On the contrary, the faster the air flows through the core, the less it will increase in temperature on its way through, making the exit temperature and the average cooling air temperature lower. This increases the differential between the average core temperature and the average air temperature, increasing the heat transfer. Increasing airflow by speeding up the fan, by providing an improved fan, by providing or improving the fan shroud, by reducing air restrictions in the grille or engine compartment, or by providing recirculation shields to prevent air from bypassing the core, will all improve heat transfer and cooling.

-Improvement Rule #2- Anything you can do to improve airflow through the radiator core will help. Anything that blocks or slows airflow, either before or after the radiator, will hurt.
Radiator Face Area

As we have seen, cooling air becomes warmer as it passes through the radiator. Coolant in the back row of a radiator is cooled by warmer cooling air that coolant in the front row of a radiator. Increasing the face area of a radiator exposes more coolant to the coolest ambient cooling air, increasing the radiator heat transfer capability.

Increasing the radiator face area may not be practical in all cased because of space limitations. However, similar improvement may be obtained by relocating any air conditioning condenser, or oil cooler which may be in front of the radiator, thereby exposing more of the face area of the radiator to the coolest ambient cooling air.

-Improvement Rule- #3 Increasing the face area of the radiator by making the radiator larger will help. Relocating other heat exchangers that were in front of the radiator in order to expose more radiator face area to ambient cooling air will also help.
 
I think factory 4-core Muscle car era brass copper radiators match or slight better than most modern aluminum.
Super hard o find used and when you find one mint or NOS GM it's $2000 to buy it.
Even good leaky cores to be rebuilt worth $500 today . For 100 % factory correct .

Aluminum Big Griffin Universal Fit Race radiator my 1st pick. They just work !
 
I found this info posted else-ware
keep in mind theres NO FREE LUNCH,
you get what you pay for in most cases,
you can find a radiator that fits most cars for under $150- to well over $900 ,
and yeah theres a big difference in quality and efficiency,
but that does not indicate the cheapest or most expensive option,
is going to be the best choice, you'll need to ask questions, measure accurately, think through your options, & shop carefully.


https://becool.com/pages/direct-fit-classic-series-radiators

https://www.summitracing.com/parts/rad-che542/year/1985/make/chevrolet/model/corvette



https://www.speedcooling.com/blog/category/radiators/3-row

hree Row Snake Oil: The Gift The Keeps On Giving – Giving You Grief.
Posted on July 8, 2016 by Tony


Let’s review what we’ve learned in the previous posts. We learned that there are many old wives tales about aluminum radiators, most of which are not true. Then we learned that aluminum is lighter and stronger than copper/brass. As hot rodders, we exploit this lighter and stronger aspect of aluminum to build aluminum radiators that cool significantly better than their copper/brass counterparts.

The reason aluminum cools better is quite simple: bigger tubes. Bigger tubes are a culmination of all the positive aspects of aluminum put into action. Bigger tubes means fewer, larger tubes are needed to get the same amount of cooling done. Because there are fewer tubes, there are fewer tube gaps. These tube gaps act like speed bumps and slow down the cooling air as it flows over the core.

Back in the era of copper/brass radiators, snake oil companies started building cheap 4-rows. They did this by using tall fin heights and small tubes. A cheap 4-row radiator would have 32 rows of tubes vertically and only use ⅜” tubes. A good high quality 4-row will typically have 38-40 rows of ⅝” tubes. That’s a huge difference.

Just like the snake oil 4-row copper/brass radiators, there are snake oil aluminum radiators. These come in the flavor of 3-row and 4-row aluminum radiators with ½” cooling small tubes. From our previous discussion on aluminum, you might be wondering why would anyone want to make aluminum radiators with small ½” cooling tubes? Doesn’t that defeat the entire benefit of using aluminum with larger, fewer rows?

3RowGimmickCore-767x1024.jpg


Yes, it does defeat the entire purpose of aluminum. So why would anyone make an aluminum 3-row or 4-row radiator? The reason is quite simple: to lighten your wallet and fatten theirs. They are suspecting you aren’t educated on radiators enough to know the difference. And in most cases, they are correct. It’s a marketing gimmick.

These 3-row and 4-row aluminum radiators are made in China. And the reason is quite simple, because no reputable American company would ever build an aluminum radiator with less than 1” cooling tubes. In fact, you are far better off with a 3-row copper/brass radiator than you are with a 3-row aluminum radiator.

championfactory-1024x768.jpg


Enter the Chinese invasion. If you know anything about the Chinese, they will literally do almost anything for money. Even if it makes zero engineering sense. No reputable cooling company will ever sell you a 3-row or 4-row aluminum radiator with less than 1” cooling tubes. Yet the Chinese are more than happy to do it since they have zero to no morals. They will do anything for the precious American dollar.

You will see these 3-row and 4-row gimmick radiators all over the internet. And they make outrageous claims of being able to cool upwards to 700 horsepower, which isn’t true at all. So you may wondering, if this isn’t true, then how can they be selling these things without customers complaining all over the place that they don’t cool well?

That is the second piece to the snake oil puzzle. Most of the people buying these 3-row and 4-row gimmick radiators have low horsepower engines. The guys buying these radiators that truly have high horsepower engines are finding out the hardway: 3-row and 4-row gimmicks are not going to cool a high horsepower engine in the summer heat.

We know this since they are blowing up our phone as soon as the weather gets hot. They are baffled. They bought this radiator off Ebay that said it would cool 700 horsepower, yet it won’t cool their 375 horsepower engine with air conditioning in the summer heat. What is wrong? Well, what is wrong is that they were sold a gimmick with unrealistic claims.

The timing of this revelation is usually uncanny. The reason you build an engine and use good components in your hot rod is so it’s reliable. It really sucks it’s 90 degrees outside and you click on your Vintage Air setup only to find your engine overheats. And it really, really sucks if mama is in the car. You just spent a small fortune upgrading your cooling system and your engine is still overheating.

Yes, this does suck. However you are now enlightened and able to steer clear of the 3-row gimmick.

In our next e-mail, we will discuss the Super Gimmick Combo guaranteed to cause you grief: 3-Row Gimmick Radiator with Gimmick Fans.

Posted in 3-Row, Radiators, Welcome Series | Leave a reply
Falling For The Three Row Gimmick
Posted on June 24, 2016 by Tony
In our last post, we covered copper brass radiators and compared them with aluminum. We left off by comparing the thermal conductivity of aluminum with copper/brass. Copper/brass has almost twice the thermal conductivity of aluminum. Yet, aluminum radiators can transfer a lot more heat than their copper/brass counterparts and keep your engine running a lot cooler.

So how in the world can this be?

Aluminum is a much stronger material than copper, which is what gives aluminum a huge edge in keeping your engine running cooler. Why the strength matters comes down to the radiator tube size. Aluminum radiators are typically made with 1”, 1-¼”, 1-½” and 2” cooling tubes. Copper/brass radiators are typically made with ⅜”, ½” or ⅝” cooling tubes.

radiator_illustrationfig11T-1024x401.jpg


As you can see, aluminum radiators are made with much larger cooling tubes. These larger cooling tubes are the reason why aluminum cools better. And the reason aluminum radiators use larger tubes is because aluminum is stronger. If we tried to make a copper/brass radiator with 1” tubes, the tubes would burst because they can’t handle the pressure. That’s why the largest cooling tubes use in copper/brass radiators are ⅝”. With aluminum radiators, cooling tubes can be made up to 2” in size. That’s a 3.5 fold difference.

Why does size matter?

Like in many areas of life, size does matter. Let’s compare two radiators. The first is a copper/brass radiator with 3-rows of ⅝” tubes. Doing some simple math, the total cooling surface area is 3 x ⅝” or 1-⅞” total of cooling surface area. To put it in decimal, 1.88” of surface area.

The second radiator in our comparison is a 2-row aluminum radiator with 1” tubes. Doing some math again, and thankfully if math isn’t your thing, this math is simple: 2 x 1” = 2.0” of cooler surface area.

So the aluminum radiator has a slight edge over the copper/brass radiator in terms of surface area. Yet the copper/brass has a huge lead over the aluminum in thermal conductivity. Which might lead you to believe there is something else at play that gives aluminum an advantage over copper/brass. And you are correct.

The main reason aluminum performs so much better than copper/brass is tube gaps. Tube gaps are the spaces between the tubes in the radiator core. Because copper is weaker than aluminum, copper requires larger tube gaps in the radiator. This is because if the wall thickness in the header is too thin, the header will crack. On copper/brass radiators, the tube gaps are typically ⅜”. Yet on aluminum radiators, the tube gap is only ¼”.

radiator_illustration22-1024x431.jpg


These tube gaps are hugely restrictive to airflow across the radiator core. They are like giant speed bumps that slow the air down and cause higher pressure drops across the radiator core as air flows across it. How does this affect your cooling?

Well, it’s quite simple. Let’s say you have a 2500 CFM 16” electric cooling fans. When cooling fans are rated for CFM, they are rated with what’s called a no-load condition. That means if you held the fan up in the air with no restriction in front of it, it would move 2500 CFM. Yet when you bolt it on to a radiator, it’s going to move a lot less air because it now has to pull air through the radiator core.

This 2500 CFM fan bolted to the 3-row copper/brass core might only move 1100 CFM of cooling air. Yet the same cooling fan bolted to our 2-row aluminum radiator might flow 1700 CFM, even though the core is thicker than the copper/brass radiator. How can that be?

It’s because of the tube gaps. Tube gaps make a HUGE difference in airflow of a radiator core. The fewer and smaller the tube gaps, the better the core will flow. You can see the aluminum has only 1 tube gap whereas the copper/brass radiator has 2 tube gaps. This difference in tube gaps is what gives aluminum a HUGE advantage in keeping your engine cool.

There are also a few other reasons that give aluminum a significant advantage over copper/brass radiators.. Since aluminum is a stronger and lighter material, this affects how dense the cooling fins can be. If the core becomes too heavy because of the weight, the fins at the bottom of the radiator can collapse because they can’t handle the weight of the radiator.

This is where aluminum has a triple advantage. Not only is it stronger, it’s also lighter. Which means the fins can be made with thinner material while still keeping the structurally core radiator strong. Thinner material results in much more efficient heat transfer. And since the material is much lighter, that means we can crank up the number of fins in the core without causing the fins at the bottom to collapse from the weight above it.

By the way, I don’t recommend handling electric fans that are not mounted to a shroud. You may think electric fans are not powerful enough to do harm, yet they are extremely powerful and need to be handled with care. I speak from experience since I lost ½” of one of my fingertips testing fans! Electric fans can be extremely powerful and need to be handled with care.

So in the next e-mail, we will tie it all together and how you how just like snake oil companies came in and sold snake oil 4-row copper/brass radiators, they have now moved into selling snake oil 3-row aluminum radiators.
 
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Some Guys like Dewitts.
Some like Be Cool....I had one it was well made and expensive at $650. Worked good with an Olds 403 but failed with an Olds 425 to keep it cool.

Griffin Race Radiator Universal Fit my Favorite now.
 
That Mishimoto Radiator is a Good Aluminum radiator also.
Import guys use them and some 5.0 Mustang guys.
They don't cater to hot rod cruisers.
Just Street Drag Racers and full drag race track.
 
In one of the most unexpected developments, apparently the "Copper Development Association" is putting some significant money into significantly advancing and attempting to bring back the popularity of copper-based radiator designs (I'm guessing for heavy duty apps).

SIGNIFICANTLY DIFFERENT copper radiator designs may be coming.

35-40% less weight.
Using very thin components that allows +30% airflow through them vs. aluminum designs.

They're using a special (well, sounds special to me as I've never heard of it...) brass alloys so that they can be brazed without solder or flux (75% copper, 5% nickel, 15% tin, 5% phosphorus)
More compact cores with shorter fins that look more like aluminum fin heights

They're getting rid of the gaps between tube rows by using the "B" shaped tubes that are effectively a single large tube welded in the metal(not anything new technology wise, but a copper "1-row" radiator product IS new AFAIK...

I'm sure the B-channel tube design helps with the strength and is also one of the main things allowing thinner walls (plus they're only 75% copper and I'm assuming the new alloy also adds some strength).


They might not be dead yet, but I fully expect copper price increases to out-pace aluminum in perpetuity, so I'm not 100% convinced this goes beyond heavy duty apps... but at least they're trying and it would appear they're trying HARD.


Adam
 
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Nano materials being used in engine coolants also looks SUPER promising based upon cooling performance improvements alone, but who knows what kind of problems these things will introduce...

Given that most coolants at very high temps can't even stop the calcium salts from falling out of solution, I'm not holding my breath that tiny metal particles are going to remain in solution or not cause other issues. (I saw testing info on one that said it worked really well as long as the pH was kept to 6 or lower... Yeah, that'll be great in a cooling system... Acid and metals. Maybe the cooling system could double as the battery? -LOL!)

Way to early to say, and most of the research is behind research document paywalls still.
 
I've only heard of a few people not running pressure in there cooling systems. I'm going to go through this thread and read about it.
That's because it's moving in the opposite direction of best practice and means a less efficient cooling system that's more likely to boil-over and given you problems on hot days or when you're hooning around.

-I think "luck" and "so far" are appropriate statements when running a cooling system with no pressure. Eventually that luck will run out. Don't leave it to luck. The house / Murphy always wins if you play long enough.

If you're running a 50/50 blend of "green" coolant, you've dropped your boiling point to 223F (from 259F if you ran a stock rad cap).
Your temperature sensor is only measuring general area, AVERAGE temperature. The instant peak temperatures of the metal just above the combustion chamber, and especially the exhaust side often reach several hundred degrees -which causes localized boiling there. -As the coolant gets hotter, it can actually carry away more heat, but ONLY as long as it remains a liquid; your coolant can only reach 223F before you get some localized boiling and the coolant can't carry away heat from the hottest part of the engine. Just a normal 12 lb radiator cap pressure installed when the coolant is COOL, will boost the boiling point of your fluid by 36 degrees. You'll gain 36 degrees of extra continued heat removal capability (anti-boiling capability).

If you use the extra boiling "breathing room" with a high-pressure cap, you also may be able to run a higher % of water in your cooling system. Water -pure water at low temps can hold / remove almost TWICE as much heat as ethylene glycol (which is still better than propylene glycol in Dexcool). More water also means your mix as less viscosity and flow will ALSO increase. -Extra water means you need more anti-corrosion protection so an anti-corrosion additive that's compatible with your coolant. Even your champion radiator, which is generally believed to be using VERY thin radiator tubes, is rated by the manufacturer to support 16 PSI of low-side pressure (Champion sells 16 PSI rad caps). Better radiators with slightly thicker walled tubes will go higher still with even a 3x safety margin on rated burst pressures. C&R's radiators are rated to 100 PSI, but use more exotic extruded tubes with internal trusses for that strength (they're one of two radiator MFGRs approved for Indycar so they needed to support 100 PSI).

Modern NASCAR, Formula 1, and Indycar racing is actually taking the concept to extremes and they will run with up to 280 -290F water under extreme pressures, so that they have an ultra-efficient cooling system that doesn't require much airflow and they can block off the airflow to the radiator to improve aerodynamics and downforce. They obviously are building the whole systems to deal with more pressure and more temperature. -They even have sealed stainless tanks with shrader valves so they can pre-pressurize the cooling system to higher levels as the outside air temperatures climb higher to prevent boiling over. When NASCAR cars do qualifying the grill is now typically 100% blocked off with ZERO airflow so that they can get the best times and as soon as they exit to the pits their teams have these huge "cool down units" that they hook up and then inject ice water into the engine and cooling system to try and help the engines survive. (But they're creating lots of other problems like breaking internal welds in their radiators from shock cooling and the rapid contraction of aluminum.) -NASCARs have tear-away plastic strips in front of them, so if a car is running slightly too hot as the track and weather warms up, they can tear away a TINY bit more area and provide a bit more cooling for a bit more aero drag.

We don't have racecars and our engines have to run on pumpgas (at least mine does, I'm not paying for race gas!) so we can't deal with those temps, but the concepts still apply. Pressure is GOOD for a cooling system, even one running at low temps for good performance.

There's also the issue that as coolant flows through your engine, it accelerates and decelerates as it encounters restrictions (in the heads, past the thermostat), when it accelerates the localized pressure DROPS, and the localized boiling point DROPS and you can get cavitation (usually at the water pump inlet), which dramatically reduces cooling, but ALSO causes physical damage to the water pump impellers and even the inside of the case -cavitation damage often involves nasty pitting.

No pressure cooling systems are playing with fire. There's only downsides, I can't say I can even think of an upside, except maybe a decreased risk of coolant leaks? (and a normal pressure system won't have leaks, so I'm really stretching to find anything positive about a no-pressure cooling system for an automotive app)



Adam
 
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THANK YOU... NICE POST NewbVetteGuy


yes Id have too agree, that a non pressurized cooling system has several potential flaws
, in fact I've personally never seen it done successfully ,
I've always recommended the use of 21 psi radiator caps
but as I stated,
"if its working flawlessly for you, why change?"
 

"if its working flawlessly for you, why change?"​

I was a professional risk manager for 5 years, and for me it's always about risk/reward trade-off.

There's no reward, and real risk of a boil-over. The likelihood of occurrence of a boil-over given enough time and our increasingly bananas-hot summers, IMO reaches 100% if the time-horizon is expanded out far enough.

My risk tolerance might be lower than most people though.

Adam
 
yes...I should have stated that a bit differently,
my sense of humor gets me in trouble at times

It was meant in a kind of "tongue in cheek" :facepalm:
I though it was rather obvious, how in hell can can you continue,
use of a non-pressurized cooling system,
without at least requiring constant and frequent coolant replacement
Id also point out that STEAM POCKETS form inside coolant passages ,inside cylinder heads,
greatly reducing cooling efficiency in a non-pressurized cooling system

1692551773036.jpeg

BP_absP_high_F.jpg


this kind of reminds me of a story involving one of my sons,
my sense of humor gets me in trouble at times
my wife pulls me aside one day and says my 4 year old sons acting rather strange,
he walks around the home staying as far from electrical outlets as he can?
I laughed and said, Ill clear that question up for you... this morning I heard him scream, I come out and find him crying,,,
he had tried to put a bobby pin or two in the electrical outlet and got his fingers zapped,
I found him, and told him, never do that again... theres an invisible monster that lives inside the walls of the house, called "ELECTRICITY"
he looks out of those outlet windows and if you poke him, with anything in an outlet,
with something he will bite the hell out of you!
he can't get out of the wall, but if you get too close to an outlet with a bobby pin he can damn sure reach you!

she looks at me and says GREAT, now you can figure out how to get him to sleep, knowing theres a MONSTER living in the walls of our home!
 
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yes...I should have stated that a bit differently,
my sense of humor gets me in trouble at times


this kind of reminds me of a story involving one of my sons,
my sense of humor gets me in trouble at times
Hahaha!

I'm glad I'm not the only one. My sense of humor tends to be more likely to get me in trouble at work than at home, but I also have a strange sense of humor that I need to tone down when I meet new people. I've got a 7 year old and an 8 year old son and totally identify with your story.

Luckily I do this enough that my kids are constant skeptics of what I'm saying.
I call it "fool-proofing" my kids, so that they won't be easily fooled and ARE skeptical. It DOES mean that they sometimes don't believe REAL things that are hard-to-believe, but, I think it's a good trade-off.

I get into trouble when neighbor kids or my kids' friends come over and I tell tall tales and all the other kids believe it and start to look concerned, my kids have to tell them "No, never believe my dad!"; LOL!

Adam
 
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