Maybe you're restoring your Corvette or just can't stand another hot summer with the A/C turned off because your Corvette runs too hot. It's probably time to replace your original copper/brass radiator with a high-efficiency aluminum unit. You know what we mean. You can run the A/C as long as you're moving at highway speeds, but even at speed, the temperature is elevated. When you sit in traffic and idle for a while, the temperature continues to creep up and your anxiety builds. You've tried all the easy stuff, including a lower temperature thermostat, maybe added an electric fan (if you have an engine-driven fan), or possibly tried some miracle cooling liquids. Nothing you have done so far has helped. No problem. A new aluminum radiator can save your Corvette from major future damage.
A sharp engine compartment...
A sharp engine compartment is useless without a dependable cooling system.
Aluminum radiators are, in most cases, at least 30 percent more efficient than copper/brass radiators. The primary reason is aluminum radiator tube configuration allows more tube surface to air than copper/brass radiators. There are a few manufacturers in the aluminum radiator game now. We decided on a Dewitts radiator for Project Shark Attack because their radiators are Direct Fit, a complete drop-in with no modifications. One thing we didn't need was more fabrication during the assembly of PSA.
Dewitts specializes in Corvette radiators, and they also understand how particular Corvette owners can be about the fit and finish of their Corvette. The Dewitts radiator is unique because the tanks are stamped and, for all practical purposes, resemble the factory copper/brass tanks. The radiator inlet and outlet positions are also in the same location as the factory unit it replaces.
1 We were lucky, PSA's radiator...
1 We were lucky, PSA's radiator had been replaced with a four-core copper/brass radiator in the past. The original fan shroud was broken up and most of it was missing. Most likely that's why PSA's original engine went into meltdown. We left the copper/brass radiator in until we had the new engine ready to install. No use contaminating the new Dewitts radiator. The new plan was to install electric fans with the new radiator.
The coat of black paint on a Dewitts radiator requires a double take-you think you're looking at an original copper/brass unit. Dewitts has a black ice coating they can apply to the radiator if originality concerns you. The black ice coating is formulated to give you the original look without the heat transfer concerns of traditional paints. The welded tanks to the radiator core might give it away, but that's OK. The welded tanks mean no epoxy to act as a heat sink.
Our radiator core support was junk (like most are). We originally thought we could save ours, but once we cut into it, the rot was much worse than we thought. New radiator core supports have been difficult to find in the past. Luckily, Dewitts had one available. We didn't want to compromise the radiator install with a weak radiator core support or have the nose of the PSA drooping.
Although we decided to use electric fans on this project, they are not mandatory. The aluminum radiator will make a significant difference and work fine with an engine-driven cooling fan. The problem with engine-driven cooling fans is they work best when you need them the least. Electric fans, when controlled properly, will keep the engine temperature stable no matter what the ambient temperature is.
2 When you order your new...
2 When you order your new radiator, make sure you order radiator-to-core support seal strips so the job can progress without a hitch. With the core support cleaned up, the next step was to install the radiator-to-core support seals. The core support seals have line-up holes in them so they can be placed in the correct area. We removed the two-sided tape that the seal strips come with and used 3M weatherstrip adhesive to securely hold them in place.
3 This is the seal strip...
3 This is the seal strip installed correctly and securely. Make sure to notice where you put the upper part of the seal that angles inward. If the seal is placed too high, the radiator bracket is difficult to install. Placement is also critical for proper radiator airflow at highway speeds. The idea is to keep the air going through the radiator and A/C condenser.
4 the Dewitts radiator is...
4 the Dewitts radiator is light and easy to handle. We installed the passenger side first to allow the lower radiator outlet to pass the control arm. The radiator install was simple, but we cheated a little using the electric fans. If we had used an engine-driven fan, the hood would be off and the core support bolts loosened so the core support would move out of the way. You would then have to fight the fan shroud before the radiator finally came out.
5 Once the radiator was set...
5 Once the radiator was set in place, the lower hose was installed. This is another benefit of using the electric fans. If a stock fan was used, we wouldn't be able to touch the lower hose from above. Those electric fans made the install and any future service much easier.
Once the radiator is installed, be sure to check for electrolysis from a poor chassis or radiator core support ground. The electrolysis will eat the aluminum up in short order. One telltale sign is a black anodized look inside the radiator tanks. When you service your cooling system, the electrolysis check should be performed. If you find electrolysis, and you've been running the engine like this for awhile, fix the problem and change the antifreeze.
Use aluminum fittings in aluminum radiators, if possible. Using dissimilar metals together can also cause electrolysis and corrosion. A light coating of Teflon sealer on fitting threads is a good idea for ease of removal later. No need to use the longest wrench in the toolbox to install the fittings either. Use restraint when tightening the drain plug or drain cock.
We dropped our Dewitts radiator and core support into PSA and filled it with a 50/50 mix of Prestone antifreeze and distilled water, then hit the road to catch up with the '05 Hot Rod Power Tour. During the trip, the cooling fans would come on at 215 degrees, run for a short time, and the temperature would quickly drop to 197 degrees. We ran the A/C through all the typical traffic associated with the Hot Rod Power Tour and never saw the temperature above 215 degrees. Out on the road, 200 degrees was the norm, no matter what terrain we encountered. since that time, the cooling system has continued to perform flawlessly, and if we ever need to service the radiator, the original engine-driven fan shroud is not a concern.
PSA had logged over 10,000 miles in seven months when we decided to take the cover off the top of the radiator and found quite a bit of debris had accumulated in front of the radiator. There had been no noticeable temperature change, but eventually, the accumulation of debris would be noticed. It's a good idea to annually inspect the area between the radiator and A/C condenser for debris.
Fuel mileage is our big concern now. The Dewitts aluminum radiator can actually save some dollars in fuel costs. If the electric cooling fans are controlled properly, the stable engine temperature will allow optimum fuel usage, and if the fans aren't running all the time, the alternator load will be reduced, thus using less horsepower, which means more fuel mileage. Even engine-driven fans will benefit if a thermostatic fan clutch is used. Lower temperatures will require less thermostatic fan clutch engagement, requiring less fuel usage. What a deal-save your engine and better fuel mileage to boot!
6 The bolts that retain the...
6 The bolts that retain the radiator upper brackets can puncture the radiator tank if the wrong length is installed. The length of the upper retaining bracket bolts aren't standard and before you replace those bolts, check for proper clearance.
7 We've dropped our modified...
7 We've dropped our modified '90 radiator fan assembly in place. We used the '90 Corvette fans because the price was right. The only concern is the fans shroud requires modifying and clearance around the upper control arms. Dewitts has a set of fans that bolt right onto the Dewitts radiator, and they can install the fan package for you if you buy their complete package. This is a good idea for the Saturday afternoon warrior since the Dewitts radiator and fan assembly will drop right in place.
8 We fabricated the top cover...
8 We fabricated the top cover out of .045 sheet steel to fit tight to the radiator core support to avoid any air loss over the top of the radiator. The nice part about using the steel top cover was the original upper radiator retaining brackets could be used. We fitted the cover over the brackets and welded them to the cover.
|Project Shark Attack Sponsors|
|ACCEL||Distributor, Plug Wires|
|Advance Discount Auto Parts||Headlights, BU Lights, & Misc.|
|Auto Instruments||Instrument Gauges|
|Bill Heard Chevrolet||Misc. Corvette Parts|
|Corvette America||Door, Window, Heater Hardware|
|Corvette Central||Steering & Drivetrain Components|
|Crane Cams||Cam, Lifters, Valve Springs, Timing Chain |
|Crutchfield||Sound System, Security System |
|DeWitts Reproductions||Radiator & Carpeted Storage Compartment |
|Discount Tire Company||Locking Nuts, Lug Nuts|
|EC Products & Design ||Interior Trim Components|
|Edelbrock ||Water Pump|
|Escort||Radar Detector, G-Timer Performance Computer|
|General Motors||Emblems, Light Assemblies|
|GT Automotive||Machine Shop Services|
|Holley||Fuel Injection, Intake Manifold|
|Keen Auto Parts||Interior Boots, Pads, Trim|
|Keisler Engineering ||TKO-600 Transmission, Hydraulic Clutch Kit|
|M&H Electric||Wiring Harnesses|
|Mid America Motorworks||Custom Leather Seats & Interior|
|Mr. Gasket ||Bolts, Washers, Timing Tab|
|MSD Ignition ||Alternator & Bracket Kit|
|NAPA ||Hoses, Engines Mounts, Horns|
|Pelton Steering Wheels||Leather Steering Wheel|
|Performance Automotive Warehouse||383 Stroker Kit|
|Pure Power||Stainless Steel Oil & Fuel Filters|
|Random Technology ||Catalytic Converters|
|Scott Rose||Aluminum Welding, Special Machining|
|SLP Performance Parts||Wheels & Tires|
|Stainless Steel Brakes Corp.||Brake Calipers, Discs, Pads|
|Thermo-Tec Automotive||Interior Insulation|
9 With the upper brackets...
9 With the upper brackets welded to the cover, installation is easy. Be sure the cover has the radiator captured and tighten the bolts. We used all four of the original mounting points for the upper brackets. One of my personal dislikes is seeing the upper thick foam rubber seal between the radiator and core support always ready to come out of position.
10 The front part of the...
10 The front part of the cover provides a lip for the '90 Corvette fan assembly to bolt to. We welded nuts from the backside so the fan assembly could be easily removed and replaced. The fan assembly keeps the cover tight against the radiator.
11 As you can see here, the...
11 As you can see here, the bottom has the same retaining strip to hold to the core support. We used a piece of .065 steel angle iron and welded it to the bottom of the core support to retain the fan assembly. The same welded nut trick was used to hold the fan assembly to the angle iron.
12 We find it a lot simpler...
12 We find it a lot simpler to tighten the hose clamp from the bottom. Make it a routine to tighten the clamp and then tighten the radiator drain cock no matter which fans you use. This is the only way to tighten the lower clamp with the engine driven fan and shroud in the way. Don't forget to use some liquid Teflon on the drain cock before installing.
13 We put a light coat of...
13 We put a light coat of Permatex aviation sealer on the inside of the hoses to prevent cold water leaks. Cold water leaks occur because the clamps that retain the hoses loosen as the hoses heat cycle, even if the hose clamps are tightened regularly. The cold water leak also allows air intrusion into the cooling system, causing corrosion.
14 Hose clamps are often...
14 Hose clamps are often ignored. If you can clean up the originals, just reuse and tighten them up. In this instance, we used ABA hose clamps from Sweden because of their tightening capacity. The ABA clamps don't have any slots cut into them for the screw threads, consequently, the hose doesn't get cut as the clamps tighten. Notice that the upper part of the DeWitts tank has the correct radius and depressed area for proper hood clearance.
15 The proper way to fill...
15 The proper way to fill the cooling system is to remove the outlet heater hose. This technique ensures that air is released and coolant is at the thermostat bulb. If the coolant is too low during warm-up, the thermostat doesn't open and then a stream of cold liquid hits the engine block and radiator. Not good!
16 To check the electrolysis,...
16 To check the electrolysis, we connected the voltmeters negative connection directly to the battery. It only takes a few minutes to test and can save the engine and radiator. Remember to check the ground strap from the engine to the frame if the volt reading is higher than .5 volts A/C or D/C. The voltage should be checked while the engine is started. Starters produce high currents, and although it's for a very short burst of electrical energy, it can be very damaging long term.
17 Our radiator and fan assembly...
17 Our radiator and fan assembly are now installed in PSA. Looks sweet and works great.