My friend bought a new turbo Regal in 1984. It was not abused, but it roasted an engine under warranty. After the new engine, it still ran hot. It came with a 2-core radiator. We installed a 3-core in it. Afterward he could drive it up a long hill on a freeway on an 80-degree day floored and the temp gauge barely moved. A lot of these engines failed. GM skimped on the radiator.
According to Dewitt's radiator. In the old days of copper and brass radiators this was true. More rows meant more surface area in contact with the fin and consequently a higher heat rejection. So a 3 row was better than a two row and so on. When aluminum radiators came around the rules changed. Cooling engineers concluded that by lowering the fin height you could stack more layers of tubes. In addition, using wider tubes would increase the tube-to-fin contact area. The end result was a very high performance radiator with a huge savings in weight. The U.S. standard for performance aluminum radiator tubes is a 1.0" wide tube and imported radiators have smaller 16mm (.62") tubes. In this case a 3-Row aluminum radiator would only have a total of 1.86" of tube-to-fin contact surface which is less than the two row core with 1" tubes. The online ads for these 3-Row aluminum radiators will indicate several features of the radiator design but they avoid the issue of the tube width. A efficient radiator goes another step and offers a two row core with 1.25" tubes or (2.5") tube-to-fin contact and this would again exceed the performance of a 4-row imported core design. So, if you are researching your next purchase ask yourself about the tube width. That will tell you a lot about the heat rejection and the origin of the product. More cores doesn't mean more cooling.
Worth pondering, each subsequent row of tubes added has less impact, because the air blowing across the tubes gets hotter from the rows before it. Also, each additional row of tubes added is itself a blockage, a restriction to air movement. A wider and or taller radiator is more effective than a thicker radiator.
Correct.. I was just going to comment this but you explained it perfectly. Same issue with water cooling with computers. Thicker does help, but more surface area when possible is the better choice. Plus thicker the rad, the more powerful the fan needs to be to pull/push air through.
The application clearly makes the difference between 2 or 3 row cores in any decisions as to the choice . As was said , the wider the core the better. A 2 row core allows more airflow thru the radiator which equals more heat is pulled off the core . 2 core radiators use 2 rows of wider tubes , 3/8" tubes are the 3 core std size tube . 1/2" tubes are 2 row std size tube in all modern and replacement radiators for vintage vehicals using a 2 row core . In addition , all radiators for the last 40 years use a higher fin count per inch . This means each fin can dissapate more heat . Depending on your application, power and heat produced by the engine , and so forth will determine the radiator core size required . A 3 row will slow down airflow thru the core , but it also has more cooling capacity in certain instances. A 2 row of 1/2" tubes can cool better than the 3 row of 3/8" tubes . Size of the core is the deciding factor . So in a car that uses a crossflow radiator that's fairly wide , a 2 row of 1/2" tubes works very well as long as the fan shroud and cooling fans are in place . In older cars like 60s or 70s mustangs , the core is not very wide , so a 3 row would be more effective in higher power situations where more cooling capacity is required . The correct radiator is dependent on each application . Do your research !!
Core tube width , most factory are copper between 1/2 --11/16 inch tubes available in 2,3,4 core Performance aluminium ARE 1 , 1.25 , 1.5 Tubes avail in 2 core
When I was restoring my mom's 1986 Firebird In shop class, the one issue we kept running into was overheating issues. Would this have solved that? I always told her it would but she wouldn't buy the better radiator.
Those F bodies were tuned from the factory to run hotter than people were used to.....or comfortable with. The ecm and thermostat make it run hot. Also......... real world personal experience, those cars get hot just while idling. Some don't have mechanical fans and they rely on electric fans that only come on until the temp comes up. They also have no airflow across the radiator, but once you start moving the temp comes way down. I would make it a point to try to stay moving and not idle all day. A 3 core would have helped you some.
Not mentioned in the video is the heater core when upgrading the cooling system especally in old classics. If you dont replace or recore your heater core and upgrade everything else then the heater core is the weak link in your cooling system and its real bad when they let go all over your new carpet etc.
You missed the obvious, four and five core radiators. I haven’t seen six yet, but I think the Pielastik’s did on their intercoolers. Tractors commonly have a few cores. Have fun
What if 3-core was my only option cuz people done make many Nissan Z31 parts and the oem rads suck? Lol. I've done so much to this car and it still only makes 100hp or so ;'-D
Those two small fans and that core shroud restricting airflow at speed is bad news. Sirflow us everything. A poor design. But hey, what do I know. I was just a cooling system engineer.
so.... can a smaller area radiator be utilized if it has more rows? Custom race app. Stock size but 3 row is way too big. So is there a config to keep the cooling ratio in a different size?
My friend bought a new turbo Regal in 1984. It was not abused, but it roasted an engine under warranty. After the new engine, it still ran hot. It came with a 2-core radiator. We installed a 3-core in it. Afterward he could drive it up a long hill on a freeway on an 80-degree day floored and the temp gauge barely moved. A lot of these engines failed. GM skimped on the radiator.
According to Dewitt's radiator. In the old days of copper and brass radiators this was true. More rows meant more surface area in contact with the fin and consequently a higher heat rejection. So a 3 row was better than a two row and so on.
When aluminum radiators came around the rules changed. Cooling engineers concluded that by lowering the fin height you could stack more layers of tubes. In addition, using wider tubes would increase the tube-to-fin contact area. The end result was a very high performance radiator with a huge savings in weight.
The U.S. standard for performance aluminum radiator tubes is a 1.0" wide tube and imported radiators have smaller 16mm (.62") tubes. In this case a 3-Row aluminum radiator would only have a total of 1.86" of tube-to-fin contact surface which is less than the two row core with 1" tubes. The online ads for these 3-Row aluminum radiators will indicate several features of the radiator design but they avoid the issue of the tube width. A efficient radiator goes another step and offers a two row core with 1.25" tubes or (2.5") tube-to-fin contact and this would again exceed the performance of a 4-row imported core design. So, if you are researching your next purchase ask yourself about the tube width. That will tell you a lot about the heat rejection and the origin of the product.
More cores doesn't mean more cooling.
Worth pondering, each subsequent row of tubes added has less impact, because the air blowing across the tubes gets hotter from the rows before it. Also, each additional row of tubes added is itself a blockage, a restriction to air movement. A wider and or taller radiator is more effective than a thicker radiator.
Correct.. I was just going to comment this but you explained it perfectly. Same issue with water cooling with computers. Thicker does help, but more surface area when possible is the better choice. Plus thicker the rad, the more powerful the fan needs to be to pull/push air through.
Little relevancy if the rest of the system is fubar.
Very helpful video! I need a new radiator in my General Lee as mine overhears in traffic after a long period of time. Good intro to the topic!
Core number is only %50 of getting the radiator correct. For a cross flow the proper number of passes makes a huge difference.
The application clearly makes the difference between 2 or 3 row cores in any decisions as to the choice . As was said , the wider the core the better. A 2 row core allows more airflow thru the radiator which equals more heat is pulled off the core . 2 core radiators use 2 rows of wider tubes , 3/8" tubes are the 3 core std size tube . 1/2" tubes are 2 row std size tube in all modern and replacement radiators for vintage vehicals using a 2 row core . In addition , all radiators for the last 40 years use a higher fin count per inch . This means each fin can dissapate more heat . Depending on your application, power and heat produced by the engine , and so forth will determine the radiator core size required . A 3 row will slow down airflow thru the core , but it also has more cooling capacity in certain instances. A 2 row of 1/2" tubes can cool better than the 3 row of 3/8" tubes . Size of the core is the deciding factor . So in a car that uses a crossflow radiator that's fairly wide , a 2 row of 1/2" tubes works very well as long as the fan shroud and cooling fans are in place . In older cars like 60s or 70s mustangs , the core is not very wide , so a 3 row would be more effective in higher power situations where more cooling capacity is required . The correct radiator is dependent on each application . Do your research !!
4 row master race reporting in!
I'm making 5 row rads for $350 a radiator
Core tube width ,
most factory are copper between 1/2 --11/16 inch tubes available in 2,3,4 core
Performance aluminium ARE 1 , 1.25 , 1.5 Tubes avail in 2 core
Good guidelines for general information. Well done on the video. Any time you buy do your research & call a specialist on the tech support side.
What about double pass?
When I was restoring my mom's 1986 Firebird In shop class, the one issue we kept running into was overheating issues. Would this have solved that? I always told her it would but she wouldn't buy the better radiator.
Those F bodies were tuned from the factory to run hotter than people were used to.....or comfortable with.
The ecm and thermostat make it run hot. Also......... real world personal experience, those cars get hot just while idling. Some don't have mechanical fans and they rely on electric fans that only come on until the temp comes up. They also have no airflow across the radiator, but once you start moving the temp comes way down. I would make it a point to try to stay moving and not idle all day. A 3 core would have helped you some.
@xmo552 she had the fan wired with a switch it was always on.
Not mentioned in the video is the heater core when upgrading the cooling system especally in old classics. If you dont replace or recore your heater core and upgrade everything else then the heater core is the weak link in your cooling system and its real bad when they let go all over your new carpet etc.
You missed the obvious, four and five core radiators. I haven’t seen six yet, but I think the Pielastik’s did on their intercoolers. Tractors commonly have a few cores. Have fun
What if 3-core was my only option cuz people done make many Nissan Z31 parts and the oem rads suck? Lol. I've done so much to this car and it still only makes 100hp or so ;'-D
Those two small fans and that core shroud restricting airflow at speed is bad news. Sirflow us everything.
A poor design.
But hey, what do I know. I was just a cooling system engineer.
so.... can a smaller area radiator be utilized if it has more rows? Custom race app. Stock size but 3 row is way too big. So is there a config to keep the cooling ratio in a different size?
4 core run cool.
Respectfully ....
Thickness.
Not Width .
Aluminium radiators are garbage. USE 4 CORE BRASS, A BIG FIXED BLADE FAN AND A SHROUD.
FROM australia