Project Swedish Meatball has been LS swapped, with boost coming from a 76mm Summit Racing turbo. To keep our engine happy and reliable, we’re going to need to turn our attention to upgrading the cooling system. In this article, we’re going to look at why you need to upgrade the radiator of your V8-swapped vehicle.
Cooling System Basics
To understand the basics of how a cooling system works, we turned to the experts at PROFORM Parts. Located in Warren, MI PROFORM Parts offers quality innovative radiator system solutions for customizing and performance. These include direct-fit, LS conversion, V8 conversion, and universal models.
“The cooling system keeps the engine from overheating,” explains PROFORM Parts Marketing Director, Ryan Salata. “For performance vehicles especially, maintaining an efficient cooling system is key to achieving and sustaining peak power and reliability.”

If you’ve V8-swapped a vehicle, that puny OEM radiator just won’t cut it. You need to upgrade to a larger and more efficient radiator to avoid cooling issues.
With an efficient cooling system properly managing heat, you’re more likely to prevent damaging detonation, otherwise known as engine knock, and oil viscosity breakdown. It also helps prevent the cylinder head and/or block from warping and losing proper sealing.
Engine cooling is all about thermodynamics. In simple terms, it’s about moving heat from someplace hot to someplace cooler. The system starts when you fire the engine. The water pump circulates coolant through passages in the engine and absorbs heat from combustion as it’s running. As the temperature of the coolant rises it activates a thermostat, set at manufacturer-rated spec, which opens passage flow to the radiator. The heated coolant enters the top of the radiator and then passes through a series of fins on the way to the bottom.
The fin design increases radiant surface area and permits heat to be transferred from the coolant to the ambient air. Cruising along the highway has the added benefit of flowing air through the radiator to further help this cooling process. Once the coolant flow reaches the bottom of the radiator it has released its heat and is then pumped back into the engine to repeat the process. This closed system of absorbing and releasing heat efficiently keeps your engine running healthy.

The size of the radiator is very important in relation to how big the engine is and how much power it’s making. Going small just isn’t an option after a V8 swap.
There’s a detail Salata mentioned previously of particular importance to anyone performing a bigger engine swap or doing high-performance modifications. That is bigger horsepower = bigger temperatures = bigger cooling system required. Salata further explains, “There is a direct relationship between horsepower, radiator size, and fan flow. As horsepower increases, the radiator’s size requirements and the fan’s CFM also need to increase to effectively cool the engine, since higher horsepower generates more heat. An ineffective cooling system raises the risk of engine damage, reduces efficiency, increases the frequency of component replacements, and can result in unexpected breakdowns.”
This means you’re more likely to encounter the damaging effects the cooling system is meant to prevent. Detonation, warping engine components, and oil viscosity breakdown are all common negative effects when adding horsepower is beyond the capabilities of your current cooling system.
How To Pick The Right Radiator
The factory radiator in our Project Swedish Meatball 1994 Volvo 940 wagon was designed for its original turbocharged 2.3-liter four-cylinder, producing 163 horsepower. Dropping in 5.3 liters of turbocharged American LS goodness means its tiny radiator is nowhere near properly sized for adequate heat expulsion. In addition, cruising around in warm locations or stop-and-go traffic (or both) is going to further expose the shortcomings of this undersized cooling system.
Thankfully, we were able to pick the right radiator for our build with guidance from the team at PROFORM. There are some common mistakes people make when picking a radiator and fan for a V8 swap or high-performance build. Here’s what you need to keep in mind to avoid making any of those mistakes.

The size of the radiator is important, but you also want one that will be as efficient as possible. The last thing you need is a big radiator that takes up a lot of real estate, but isn’t providing enough cooling capacity.
First, don’t choose a radiator that is too small, in an attempt to save weight, or because of clearance issues. “You can’t have too much cooling, but you can have not enough,” mentions Salata. You’re not gaining any ground unless the coolant can expel equal or greater than the heat it takes in. You need as much cooling fin surface area as you can get. You can try to save weight or find clearance elsewhere, but don’t skimp on the size of your radiator.
Second, don’t assume any radiator core will work. Radiators can be constructed with one, two, three, four, or even five rows. Each row adds more surface area for cooling but may impede ambient airflow. Meaning more reliance on the fan(s) and the importance of having unrestricted airflow. Get a radiator with the largest coreas possible, you’ll be happy you made that choice when the car doesn’t overheat in traffic on a scorching day.
Third, don’t choose the wrong materials.. Radiators may be constructed from a wide variety of materials, including plastic, composite,brass, or aluminum. Plastic and composite end tanks are often used in stock and replacement applications and have their limits in performance modifications. Get a beefy all-aluminum radiator that will have the right amount of cooling capacity for your build.

The fan and shroud need to be a match for your radiator and its cooling abilities. The more air the fan can move the better.
Finally, pay attention to fan compatibility. Is the fan properly matched and powered for the radiator and cooling needs? Does it cover as much of the radiator core as possible? A belt-driven fan might not be enough and you might need to move to an electric fan to keep up at idle or in stop-and-go traffic. You’ll want to look at fans that move plenty of air and have a shroud that fits your radiator.
With these pitfalls in mind, now let’s build the cooling system right, starting with the radiator. There are three important factors for your high-performance V8 engine, whether you decide between a direct-fit replacement for easier installation or a universal fit that may require custom modifications.
Number one is compatibility and fitment. Ensure the radiator is compatible with your vehicle’s make and model and fits properly. The radiator should be as large as possible while safely fitting in the engine bay. It’s also important to ensure no obstructions impede airflow.
You want to maximize every square inch available when picking a radiator for your V8 swap project.
Second, cooling capacity. In general, make sure the radiator is rated within your engine’s horsepower spec. For high-performance V8s, opt for an oversized or thicker radiator to improve cooling efficiency. Choose the largest radiator that can safely fit based on how you intend to use the vehicle.
A proper fan comes next to assist the radiator and further dissipate heat from the coolant system. The fan(s) setup should cover as much of the radiator core as possible. The fan’s airflow rate, measured in cubic feet per minute (CFM), should also be based on how you intend to use the vehicle. High-performance V8 engines need more CFM to help dissipate more heat. It should be sized correctly for the shroud and without clearance issues.
An electric fan(s) has an air flow advantage. It delivers instant max output independent of engine RPM and does so without a drag on engine horsepower. However, the electrical draw will also need to be considered on your electrical system and fused accordingly.
Cooling The Meatball
With an expected 600-plus peak horsepower and plenty of torque throughout, we selected the PROFORM’s patented Slim-Fit Radiator System. It provides 1,650 cfm of fan airflow, and it can handle street driving, trips to the drag strip, or rips around the autocross course. More importantly, it’s a high-quality performance radiator we can safely fit and will function properly under the hood. To streamline the installation process, it comes pre-assembled with a shroud, electric fan, adjustable thermostat, wiring harness, and radiator cap.
PROFORM’s patented Slim-Fit Radiator System was the perfect match for Project Swedish Meatball. It has integrated fan controls, a very low profile, and the fan is recessed into the radiator itself for more clearance.
“The PROFORM Slim-Fit radiator is an excellent choice, not just for LS swaps but V8 engines in general, especially when space is limited, due to its innovative design and features,” explains Salata. “It combines the radiator, shroud, and electric fan into a fully assembled unit, out of the box, under four inches thick. Providing up to 40-percent space savings compared to traditional setups.”
The PROFORM Slim-Fit radiator is a hybrid-core design compatible with all coolants. It utilizes both traditional dual one-inch tubes and full core-width extruded tubes. The architecture reinforces the core and improves cooling efficiency. The system is constructed from TIG-welded aluminum. Together they make for a complete lightweight, durable, clean natural finish radiator system suitable for engines producing up to 600+ horsepower.
A properly sized and functioning radiator, preferably made from aluminum, is necessary for engine durability. In general, it’s best to err on the side of over-cooling with a larger size and higher fan CFM. In V8 high-performance swaps, opt for the largest radiator that can safely fit unobstructed within the engine bay. An electric high CFM flow fan(s) should cover as much of the core as possible to assist the radiator with cooling, especially at idle and in traffic.