What’s more frustrating than sitting on the side of the road with an overheated vehicle?
Whether it’s the sight of the steam coming from the hood or the smell of hot coolant splattered all over your engine compartment (or puddled underneath your vehicle), few things put a damper on weekend cruise like an overheated engine.
We’d strongly advise you to avoid this situation, and you can start by having a strong, healthy radiator for your vehicle. With help from the Summit Racing technical department, we’ve put together an overview of common radiator styles, materials, and designs. This basic knowledge will put you on the road to picking the optimum aftermarket radiator.
Crossflow vs. Downflow Radiators
Radiators are often broken down into two main styles: crossflow and downflow.
A crossflow radiator consists of a vertical tank on each side with a series of cooling tubes and fins making up its
core. The coolant travels horizontally across the core from the inlet side to the outlet side with the help of your water pump.In contrast, a downflow radiator has tanks running horizontally at the top and bottom. The coolant enters the top of the radiator and travels vertically through the core and leaves through the outlet at the bottom. Because the coolant flows from the top down, the water pump is aided by gravity, which allows the coolant to travel more quickly through the radiator.So which is better for your vehicle?
“When it comes to design, crossflow is typically more efficient due to the speed—or lack thereof—with which it moves the coolant,” said Mike Bosiljcic of Summit Racing’s technical department. “Unlike a downflow radiator, which has gravity working against it, a crossflow radiator holds on to the coolant just a little longer, allowing it to dissipate heat a little better.”
Because of its heat dissipation abilities, along with its (typically) larger core surface area, the crossflow radiator is often the best choice for high-rpm, high-output engines.
“One other reason the crossflow design has really taken off in popularity is the sleeker hood lines on today’s vehicle,” Bosiljcic said. “The downflow radiator is simply too tall to fit into lower-profile configuration.”
On the other hand, downflow radiators can provide an original, nostalgic appearance and can often fit where crossflow radiators will not. Cramming a crossflow radiator into an older engine compartment designed for a downflow will often require fabrication.
As always, you’ll need the proper fan, water pump, and thermostat to maximize your radiator, whether it’s a crossflow or downflow design.
Aluminum vs. Copper-Brass
The two main types of radiator materials are aluminum and copper-brass.
Copper-brass radiators came standard on older vehicles and were found on some vehicles all the way into the 1980s. For a vintage or period-correct look, it’s hard to beat a copper-brass radiator. It’s also hard to beat copper-brass for heat conductivity.
So why the switch to aluminum radiators in recent years?
While copper-brass is a great heat conductor, it is also a relatively weak material when compared to aluminum. To avoid ballooning or bursting under pressure, the diameter of the copper-brass tubes that carry coolant needs to be kept small. And that’s a big problem when it comes to cooling capabilities.
Because aluminum is stronger material than copper-brass, aluminum tube diameter can be increased to flow more coolant. That means more coolant is exposed to the heat exchange process, giving the radiator a greater cooling capacity.
A second—and more obvious—advantage to an aluminum radiator is weight. Because aluminum weighs approximately 60 percent less than copper-brass, an aluminum radiator is often the ideal choice for high performance and competition engines.
There’s one more advantage to aluminum radiators: reduced row quantity within the radiator core.
Row Quantity vs. Tube Size
As we mentioned earlier, radiators consist of a row or several rows of tubes and fins, which transport the coolant. Because aluminum is much stronger than copper-brass, tube diameter can be increased without having to add thickness to the tube walls (a necessity when increasing the size of copper tubes). As a result, a two-row aluminum radiator with one-inch tubes will dissipate heat at about the same rate and efficiency as a five-row copper-brass radiator with smaller, half-inch diameter tubes.
This two-row design also causes less air restriction through the core, allowing your vehicle’s fan to more effectively aid in the cooling process.
“Most high performance radiator manufacturers have abandoned the idea of more rows being better,” Bosiljcic said. “Now it is about core thickness and cooling tube size—even when comparing aluminum radiators. The larger tube radiator is much more capable of displacing heat just due to it’s increased capacity and the only difference that may be noticed is that the core is slightly thicker.”
The Verdict: Choosing the Right Radiator
We’ve covered the basic radiator styles, materials, and designs. In general, aluminum radiators are the ideal choice for high performance, high-output vehicles, competition cars, and custom street rods. Copper-brass radiators make a great choice for restorations or a nostalgic look.
According to Bosiljcic, there are a couple more rules of thumb:
“Bigger is always better when it comes to radiator selection,” he said. “People should also remember that universal radiators are just that—universal. This makes a direct-fit radiator a much better option in the end if available.”
To narrow down the choices for your specific application, here are few things you should know when you begin shopping for a radiator:
Armed with this knowledge, your parts salesman will be able to steer you in the right direction.
Running to a vehicle workshop frequently can be infuriating. What can be worse? Being stranded on the side of the road with an overheated vehicle! Nothing puts a damper on a joyful cruise like steam coming from the hood or the smell of hot coolant splattered all over the engine compartment. Besides, what causes these troubles? Undeniably, overheating and engine breakdowns or unnecessary and frequent servicing of an engine is caused by faulty or obsolete radiators.
Most people do not pay much attention to these components as they do not add to the external beauty of the vehicle. Consequently, their cars end up hurling to the workshop on a regular basis.
Can this be avoided? Most definitely, YES! To prevent this situation, all you need to do is take precautions, and having a decent vehicle radiator is a good place to start.
We've compiled a list of the most common radiator options. With this knowledge, you will be able to select an aftermarket radiator that is perfect for your vehicle.
As you know, the radiator in a vehicle is a heat exchanger that cools an internal combustion engine.
Modern engines generate an enormous amount of heat. As the coolant flows through and around the engine, it absorbs heat and transports it to the radiator, protecting it from overheating. The coolant enters tubes in the radiator as the car moves, air passes through the rows of tubes, cooling the coolant. As a result, heat is dissipated through the air, and then the coolant is cycled back into the engine block to continue cooling it. Allowing that the radiator is able to dispel heat quickly enough, there is no danger of the engine overheating. It is likely that the engine will overheat if the radiator is inefficient or inadequate for the amount of horsepower being produced.
to simplify your decision about choosing the right radiator, we will showcase various kinds of radiators. This will help you to compare and choose your next radiator.
Older vehicles had copper-brass radiators that were standard until the 1980s. Copper-brass radiators are known for their superior heat conduction abilities.
So how does aluminum even come into the picture?
Although copper-brass conducts heat well, it is relatively weak when compared to aluminum. Coolant tubes made of copper-brass need to be kept small in diameter in order to prevent ballooning or bursting under pressure. In terms of cooling capabilities, that's a big problem.
Our Verdict: Aluminum tubes can have larger diameters than copper-brass tubes due to aluminum’s strength. Consequently, the radiator has a greater cooling capacity because more coolant is exposed to the heat exchange process. Due to aluminum’s low weight, aluminum radiators are often the ideal choice for most engines.
There are two different types of radiators: crossflow and downflow.
In a crossflow radiator, cooling tubes and fins make up the core, which is surrounded by vertical tanks on each side. With the aid of your water pump, coolant travels horizontally across the core from inlet to outlet.
There are two horizontal tanks at the top and bottom of a downflow radiator. By entering through the top of the radiator, the coolant travels vertically through the core and leaves through the bottom outlet. Since coolant flows from the top down, gravity helps the water pump move coolant through the radiator more quickly.
Our Verdict: Due to the speed at which crossflow moves the coolant, it is typically more efficient in terms of design. Crossflow radiators retain coolant for a longer period of time, which allows them to better dissipate heat. Crossflow radiators are often the best choice for high-output engines due to their heat dissipation capabilities and (typically) larger core surface areas.
In a radiator, the coolant is transported by a row or several rows of tubes and fins. Aluminum is much stronger than copper-brass, so you can increase tube diameter without adding thickness to the tube walls (as with copper tubes). Because of this, two-row aluminum radiators with one-inch tubes dissipate heat nearly as efficiently as five-row copper-brass radiators with smaller tubes.
Our Verdict: The idea that more rows are better has been abandoned by most high-performance radiator manufacturers. In comparisons of aluminum radiators, core thickness and cooling tube size are now critical. There is only one difference between the smaller and larger tube radiators, the core of the larger radiator is slightly thicker.
Following the information about different types of radiators, which is better than the other, and why, here are some additional points you can keep in mind when choosing the right radiator.
If properly maintained, radiators typically last 8-10 years. In most cases, people only need a replacement radiator if theirs has been damaged or if a more powerful one is needed.
However, one should not wait for their vehicle to suffer completely and then go ahead to change their radiators. One must have their radiators checked or replaced if faced with these problems: -
Trouble in Pressure
It's possible to have either too much or too little pressure in your radiator if your radiator cap fails. In either case, the result is the same and leads to overheating of your engine. Replace your radiator cap in this case. Leaks can cause pressure problems, and pressure problems can cause leaks. The radiator's pressure can be tested at a shop.
Leaks
You should never ignore coolant leaks. Several household pets have died from antifreeze poisoning. If you see a leak, you don't necessarily have to replace your radiator. A leak indicates that something isn't working and that your hoses should be checked, but a leak can occur at any point in the cooling system.
Rust and Corrosion
A rusty radiator or debris clogging it is another reason to check your engine. Flushing out your radiator or replacing it will be necessary in this case.
Aluminum radiators are generally recommended for high performance, high-output vehicles, as well as competition cars. For a nostalgic look or restoration, copper-brass radiators are a great choice.
The following factors will help you narrow down your choices when choosing a radiator:
Enlightened with this knowledge, you can have a discussion with your regular garage mechanic or your spare parts salesman and then choose the best and optimum radiator for your vehicle.