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Mustang Cooling System - Project Redheaded Step Child Part 9 - Tech
Keeping Your Cool
When We last left Project RSC, we had just installed a 1.7L Kenne Bell supercharger on the modified 4.6L 2V motor. Truth be told, this radiator and Meziere electric water-pump install actually took place prior to the blower install, but scheduling priorities dictated that we run the blower story first. While big-boost power numbers are a lot sexier than a cooling system upgrade, the new radiator and electric water pump may well keep that blower motor alive and kicking on the street.
With any increase in power comes increased heat that must be dissipated through the cooling system. In our case, the increased power was not the only reason for the cooling-system upgrade. With more than 200,000 miles logged on the Two-Valve Mustang, the factory radiator had seen more that its fair share of mileage. Since purchased from the original owner, we had to add water to the cooling system on a regular basis. Not much mind you, but it was annoying to have the coolant level light come on every so often to remind us something was amiss. Knowing our new motor was not consuming any water, we knew there must be a leak somewhere in the system.
It was only during the cooling-system upgrade that we discovered the culprit was the factory radiator. No big holes mind you, just a minor trickle that probably only manifested itself under pressure (when the system was at operating temperature). This explains why we never discovered any puddles of water (even small ones) under the car. The water just seemed to vanish. During the various stages of modifi-cation, we replaced just about every hose and clamp on the cooling system. We checked the intake gaskets for signs of a leak, but never found a drop. We even went to the trouble of performing a leakdown and compression test on the new motor, thinking a head gasket might be bad. The Coast High Performance motor ran even and strong, so the missing coolant remained a mystery until we decided to install the new Fluidyne radiator and Meziere electric water pump. It was during the coolant system upgrade that we found evidence of the leaks in the side of the factory radiator. Either the sealing gasket or the plastic (end tank) itself had eroded enough to allow the smallest amount of coolant to escape, and probably only under pressure (when driving).
Having more than doubled the factory power output of the non-PI Two-Valve motor, we decided the hot motor deserved something more than a stock radiator rebuild or replacement. What this 400-plus-horsepower supercharged street motor needed was a suitable cooling system. While we were looking to improve the cooling capacity, we didn't want to have to redesign the factory system. Basically, we were looking to maximize cooling while minimizing installation headaches.
As luck would have it, Fluidyne had exactly what we were looking for with its Direct Fit performance radiator. The Direct Fit promised significant improvements in cooling capacity yet bolted directly in place of the stock radiator. "Bolts in minutes with simple hand tools"-yeah, we've heard that one before. What usually happens when we install performance products is that the minutes turn to hours and the simple hand tools apparently include a plasma cuter and TIG welder. Beware of the phrase "some assembly required."
Actually, we were pleasantly surprised by the Fluidyne Direct Fit radiator, as the system per-formed exactly as advertised. It bolted right in place, even accepting the factory cooling fan assembly without so much as one single installa-tion headache. When Fluidyne says its radiators are a Direct Fit, it's really true.
In addition to the Fluidyne radiator upgrade, we also installed a Meziere electric water pump. Having run the Meziere pump on just about every motor used in the many Mods for Mods series (not to mention the author's most recent book on modular performance), the pump has proven itself both effective and reliable. Combining a powerful electric drive motor with an efficient impeller design makes for one serious circulation pump. Unlike the pump employed on literally thousands of engine dyno tests, we requested that the 4.6L pump include an idler pulley assembly that allowed us to run the pump with the factory serpentine accessory-drive assembly. The snout of the electric water pump features a bearing assembly that allows the idler pulley to rotate freely without affecting the rotation of the internal impeller. Thus the impeller is free to circulate the coolant irrespective of engine (or accessory) speed. This is an important feature as it not only allows the water pump to be installed with the factory serpentine drivebelt, but it also provides significantly more coolant flow at lower engine speeds (like when the car is sitting in traffic in the scorching heat). The pump was hooked to a 12-volt ignition-on source so that it was only energized with the engine running.
Check out the supplied photos for a full rundown on the Fluidyne radiator install (the Meziere pump required only four bolts). It is important to note that we had previously installed a 180-degree thermostat. Prior to installation, the thermostat was drilled to provide an escape route for the trapped air pockets that can cause localized hot spots. If the air pocket finds its way to the coolant temp sensor, a false reading can be relayed to the ECU, and the cooling fans may never be switched on. The result will be a serious overheating issue. The thermostat modification is important since it is particularly difficult to rid the modular motor cooling system of the trapped air pockets.
Speaking of cooling fans, the custom computer chips provided by Powertrain Dynamics (for all of our normally aspirated testing) and by Kenne Bell (for the supercharged combination) both featured revised fan switch points. Lowering the temperature for fan engagement allows the motor to run cooler. We like to keep the motor running near 180 degrees to keep fuel mileage reasonable. With the Fluidyne radiator, Meziere electric water pump and thermostat, and cooling fan modifications, Project RSC (even in supercharged form) is now one cool customer.