Although summer is almost over, check your cooling system for fall fun.
This one bites us in the keister more times than not - cooling systems. It's incredible how we spend large sums of money on engines, yet conveniently overlook the engine's most important support system. First - choose a high-capacity radiator to get your foundation in place - and don't do this on the cheap. Go for the most cooling capacity that will fit your application. Next - a high-flow water pump, preferably aluminum for weight reduction and improved heat transfer. A 160 or 180 degree thermostat determined by normal engine operating temperature. You don't want an engine that runs too cool. If it runs cool at 160 degrees, that's unacceptable. Warm it up with a 180-degree thermostat because an engine that operates around 180-200 degrees is a happy one. Remember - when coolant temperature is 230 degrees, oil temperature is a whole lot hotter. Engine oil begins to break down and fail at 260 degrees. Synthetics give you grace until 300 degrees.
If you're running a fuel-injected 5.0L or 4.6L engine, you must have a 195-degree thermostate for proper electronic engine control function. The engine's computer doesn't come on line until 195 degrees coolant temperature. Run it at 180 degrees and you will remain in open loop - rich fuel mixture and an engine that runs like - well - you know...
We get arguments on this, but you MUST have an anti-collapse spring in your lower radiator hose no matter what anyone will tell you. Engines that overheat only on the freeway/interstate are suffering from lower radiator hose collapse and no coolant flow. Although no one includes anti-collapse springs in lower radiator hoses, make sure yours has one.
Radiator cooling is optimized when we do the right thing. Your radiator should have a shroud. Fan depth in shroud should be half in and half out for optimum air flow. Air flow across a radiator should be smooth and without turbulence. When air moves too fast across a radiator, it cannot transfer heat out. That's why engines sometimes overheat at high vehicle speed. Extremely high air flow creates boundry layers in places you never want it, keeping a radiator from giving up its heat.
Fan capacity should always be at least 2500-3000cfm. Any less and you're courting trouble.
And finally - Marvin McAfee of MCE Engines in Los Angeles recommends heavy-duty cooling system hoses and two clamps at every junction. You can reach Marvin at 323-731-0462 or MCEEngines@aol.com.