Modified Mustangs & Fords
1969 Ford Mustang Sports Roof - Cool School
We Get A Lesson In Cooling Science With Help From National Parts Depot
We've got a '69 Mustang SportsRoof in our vintage Ford stable that's definitely in the user category. It's driven somewhere almost every weekend and regularly runs in the Silver State Classic open road rally in Ely, Nevada. Although our car doesn't have the correct chalk marks, it does have a host of high-performance goodies, including a hot 351 Windsor engine and a T-5 five-speed overdrive transmission. Held during the spring and fall of each year, the Silver State Classic has plenty of Nevada-style heat to challenge our machine, and our cooling system better be ready for it. The event means continuous high engine loads, and speeds in excess of 100 mph are the norm. These conditions had us thinking about some serious cooling system upgrades.
Our car had the factory small-block radiator out front, and at 20 by 20 inches in size, it was a lot smaller than the opening in the core support. Beside the relatively limited frontal area, the radiator core was thin and offered limited coolant capacity. Also, at home in Los Angeles, the stop-and-go traffic would regularly have our car on the verge of overheating. What we wanted was a cooling system that had enough reserve capacity to free us from any engine temperature related worries.
We consulted the experts at National Parts Depot (NPD) to see what they would recommend, and a great cooling system combination was the result. They started us out with a big-block size aluminum radiator from Griffin that was much larger than our OE 351W unit. To move air through the radiator, NPD provided a dual electric fan system from Old Air Products. New upper and lower radiator hoses from Marti Auto Works were going to be connected to a new Tuff Stuff Performance Accessories chrome water pump, which would replace our tired and squeaky pump.
When combined with a new thermostat, radiator cap, and coolant, we'd have a winning cooling system combination. The reserve cooling capacity that this setup offers will keep the water temperature down right on top of the thermostat, and it will be good to have should we ever decide to add accessories, such as air conditioning or an engine power adder. This system should be able to beat the heat whatever the situation. We're basically replacing the entire cooling system.
Although this sounds like a lot of work, continue reading and you'll see the job was relatively easy to accomplish. You should be able to do this swap on a Saturday afternoon.
Keeping Your CoolHere are a few tips we've learned over the years about classic Ford cooling systems. We're sure you've seen a few of them, but it's always good to take a refresher course.
* Don't use too cold a thermostat. Run around with a big radiator and a 160 thermostat, and your engine will never reach proper operating temperature. Choose a 180 instead.
* Don't run straight water in your cooling system. It doesn't take long for the corrosion process to begin. Unless you live in Fairbanks, Alaska, a 50/50 mix of distilled water and coolant mix is correct.
* To maintain radiator efficiency take a garden hose and clean the radiator. When the car is cold, carefully flush the core from the engine side and out the front of the car. After 1,000 miles of summer driving, you'd be amazed how many dead insects will have collected on the radiator. They will obstruct proper airflow eventually if not removed.
* If you've got an engine that hasn't been apart in years, you may have a lot of rust and debris circulating through your cooling system. Before you install a new radiator into a car like this be sure to back flush the system, including the heater core and engine block. With the new radiator in place you can use an in-line filter trap. They're available for your radiator hose to catch any particulate matter in the system.
* If your radiator has a leak, don't use a granulated metal product to plug the leak unless it's to get you out of the desert and into a radiator shop. That stuff clogs more than just the leak.
* The drain petcock on many Mustang radiators is directly over the frame. When the system is drained the used coolant runs everywhere, starting your job out with a big mess. Stick a length of hose over the petcock end and run it to the drain pan.
* Want to add coolant to your radiator, but don't have a funnel? Just lay the coolant jug flat before pouring, and there's no mess.
* When checking for proper V-belt tension, the belt should deflect less than an inch on its longest span. Too loose, and you could throw the belt or have an annoying squeal. Too tight, and you could damage the pulley shaft or bearing of the accessory you are driving and even cause fluid leakage.
* Most classic Fords do not have a catch can or overflow bottle. One can be purchased or made from a simple plastic container or bottle. This prevents coolant overflow from entering the ground and contaminating the soil. you will also have to top the cooling system off less as the overflow system will allow the coolant to return to the radiator once the radiator cools off.
* If you are using the factory metal fixed-blade fan, make sure you don't have the fan on backwards. It is easy to do. Look for the word "FRONT" on the fan or inspect the pitch of the fan blade to ensure it is pulling air from the radiator when spinning.
* Don't obstruct airflow to the radiator. Extensive lighting, custom grille work, and other cooling items in front of the radiator (A/C condenser, aftermarket oil coolers, and so on) all contribute to lack of airflow across the radiator core. Make sure you are getting the maximum amount of airflow to the radiator, and that it is going through the radiator core and not around or over it.