Unless you lived through the days of mechanical brakes and manual-choke carburetors, it can be hard to appreciate how far cars have come. Case in point; even most compact cars these days have an electric fan setup to save on parasitic horsepower loss and improve gas mileage. It wasn’t even twenty-five years ago, when most automobiles relied on huge fan blades spun by the crankshaft at the front of the engine, just waiting for a chance to separate your hand from your wrist.
Thankfully, we don’t run the same risk of amputation when working on modern muscle cars. AFCO‘s bolt-in replacement all-aluminum radiator and electric fan combo is one of the few direct replacement parts for an LS conversion in a classic muscle car, making dropping the popular LS-series of engines into older muscle cars a cinch. It was because so many aftermarket companies were starting to support these swaps that we decided to bring some of that modern swagger to our ’71 Nova, Project Swinger. We choose one of the most potent motors in GM’s arsenal, the supercharged 556 horsepower LSA engine, to swap into Swinger.
Currently found in the Cadillac CTS-V, the LSA is second in power only to the LS9 engine found in the Corvette ZR-1. The LSA engine has plenty of modern technology that engineers from 1971 could only dream of, so the old radiator and mechanical setup just weren’t going to swing with this modern monster.
Baffles, Fins, and Flow
There is no way to mate a 70’s mechanical fan to the modern automotive innovation that is the LSA engine. Instead, we turned to AFCO and their LS radiator and fan conversions for classic muscle cars to help us make a clean swap. These bolt-in LS conversion kits are essential for anyone planning on dropping an LS-series engine into a GM classic like Project Swinger. AFCO takes cooling quite seriously, and for good reason, as it is important to the performance and durability of every engine. Eric Saffell, Drag Racing Product Manager of AFCO, took the time to explain to us just how far improvements to modern engine cooling have come.
“The heart and soul of cooling is the radiator core, so that is where AFCO starts,” says Saffell. The radiator core consists of many thin metal tubes that funnel water across the engine. Cores come in two flavors; cross flow, or down flow. Cross flow radiators have water tanks on either side of the radiator core, while down flow radiators have the water tanks at the top and bottom of the radiator. The radiator for our LS conversion is of the cross-flow variety, with water flowing from the driver’s side tank to the passenger’s side. Cross flow radiators are the more efficient of the two, but there are still die-hard fans of the down flow radiator.
With a cross flow setup, you have to ensure that the water actually enters the core, and doesn’t just drop from the top of the side-mounted tank to the bottom. AFCO installs properly-placed baffles in both water tanks for just that reason. Their Double Pass system essentially the water passes from one side, across the radiator, down and then back across again, for double the cooling. A cool engine runs better and longer, and the importance of a good cooling system cannot be underestimated.
“Keeping your engine cool has a direct effect on the longevity and efficiency of your engine,” Saffell says. A hot engine runs the risk of detonation, which left unchecked, can wreak havoc. Cooling is often an afterthought, and we rarely take the time to appreciate the work that goes into something seemingly as basic as a radiator. A lot goes into designing an efficient radiator though.
“We have to determine the proper number of fins-per-square-inch, as well as the number of rows in a cross flow radiator to best dissipate the heat,” Saffell says. It is the fins that are actually responsible for cooling the coolant as it flows through the radiator. “It is basically a heat sink. The louvered-style fins draw more heat out of the water.” AFCO figures that between 14 and 18 fins-per-square-inch are enough to achieve the maximum cooling effect possible, depending on the size of your engine and how many gallons-per-minute your water pump is rated for.
So just how much cooler does the radiator make the water? “Depending on the engine setup, such as how much volume the water pump is rated at, we’ve seen the water temperature drop by as much as thirty degrees from water entry to exit,” says Saffell. “We use the largest, thickest core available to ensure both durability and to achieve maximum cooling.” This also improves their durability, and AFCO pressure-tests each radiator before sending it out, to ensure its strength.
AFCO’s radiator is made from high-quality aluminum, and is set up with the proper inlet/outlet on the correct side for your year car. There is no welding or adjusting of your car either, as these radiators are designed as a direct bolt-in for your specific model and year. They cover so many different model years of cars and trucks that it would be impossible to list them all. Everything from Camaros and Chevelles, to Corvettes and S10’s. Chances are that they have what you need for a new radiator for your classic or contemporary ride.
- AFCO LS Radiator and Fan Conversion Kits is a direct bolt-in for classic LS conversions
- Kit includes aluminum crossflow radiator and electric fan
- Radiator lowers water temperatures by as much as 30 degrees before returning to engine
- Installation requires just two wire connections to operate
A radiator is just one-half of the equation though. It only works when there is air passing through the core and over all of those thin metal fins. What happens if you are stuck in traffic, or even just lining up for a run down the quarter mile? Without proper cooling, these engines get very hot very fast, and the radiator needs a steady flow of air to cool the water. That is why back in the old days, all cars were equipped with power-robbing mechanical fans attached to the water pump pulley. These big, heavy fans drew air from in front of the radiator through it, blowing the air back against the engine.
Again, very simple and effective technology dating back to the dawn of the automobile, but at this point outdated. Pulley-driven fans steal horsepower and rob fuel economy, making it a double-whammy in today’s demanding market. GM stopped putting them on the Camaro about two decades ago. So for us, swapping a modern LSA engine into a ’71 Nova meant using an electric fan setup as well. AFCO already had the solution though.
Their LSX conversion kit includes the 16-inch S-blade electric fan from an LS1 engine. Switching to an electric fan setup has benefits for every engine out there, and the way our LSA is setup there is no place to mount a mechanical fan. An electric fan eliminates rotating mass working against the engine, saving horsepower and improving fuel economy. “It may not seem like much, but ditching the mechanical fan can free up quite a of horsepower because the engine doesn’t have to do the extra work of rotating the fan blades,” says Saffell.
Depending on your engine, you could see almost no benefit to up to five additional horsepower by losing the mechanical fan. The electric fan has a low energy draw of just 15 to 17 amps, so the additional load on your alternator isn’t going to cost much in the way of lost horsepower. Our LSA engine has a modern alternator, so we don’t have any worries, but if you have a truly ancient alternator you plan on using with an electric fan, you might want to consider an upgrade.
Mechanical fans were always robbing horsepower, but electric fans can be set up only come on when the water temperature rises. Going down the highway at 70 mph, your radiator gets plenty of air flow, so the fans don’t need to be on. But if you’re stuck in Los Angeles rush hour traffic? That’s when the electric fan pops on, cools the water down, and turns off until needed again. Without the rotating mass of the fan, your engine gets better fuel economy too (not that we are that concerned with that).“These LS engines didn’t even come set up for a mechanical fan, so it was simply a matter of making a radiator and electric fan combination that bolted into the classic body,” Saffell says.
Easiest. Install. Ever.
So you’re probably thinking, “Great, but I’m no electrical engineer. How do I install an electric fan on my car!” Well, worry not. It took us just a few minutes to install AFCO’s entire LS radiator and fan conversion onto Project Swinger.
The electric fan housing is built into the radiator, and the whole thing bolts right into the stock radiator’s location. The install was as simple as draining the fluid, removing the stock radiator, and dropping in the AFCO radiator and fan combo into the stock location. All done.
Hooking up the electric fan was a cakewalk too. There are just two wires needed to make the fan work, a power and a ground. If you want the fan to run all the time, you just hook the red wire up to a power source and viola, all done, though you are going to be running your alternator more often, which does draw some horsepower from the engine.
If you want control over when the fan goes on, you can hook the power wire up to a manual switch in the driver’s compartment, flipping it on only when you desire. Ideally though, you want the car to do the work for you.
Attaching it to a temperature sensor somewhere on the back of the block or on the intake manifold will let the fans come on as-needed. This way you get the maximum free horsepower and fuel efficiency, with the least amount of work. Naturally, this is what we did.
To really ensure our engine stayed as cool as possible, we decided to go a few extra steps. We are going to add some Red Line Water Wetter to our coolant once the engine is up and running.
In addition to its anti-rust and corrosion prevention properties, Red Line Water Wetter can drop ambient temperatures in the metal by as much as 20 degrees. This means the water stays cooler too, and we want to take good care of our fancy Cadillac engine.
AFCO radiators can be had with a few extras as well. “A popular option is the transmission cooler, which is built like a heat sink and can dramatically lower transmission temperatures,” Saffell says. Another offering, which we opted for, is the Luster finish. As you might imagine, it is a bright, shiny finish rather than the regular aluminum look.
Considering that we are dropping a Cadillac engine into our ’71 Nova, the engine bay could do with a bit of sprucing up. It really brings the engine bay alive (well that, and the 556 horsepower engine).This isn’t just some shade-tree engine swap after all; we’re doing this swap right with the help of AFCO. The AFCO LSX radiator and fan conversion swapped in so quickly, we can focus on other important aspects of Project Swinger, like getting that supercharged LSA engine up and running. We want to thank Eric Saffell and AFCO for giving us an inside look at how radiators work, and getting us on the fast track to finishing up Project Swinger.