TEN RULES FOR MAXIMUM COOLING

Make Room for an Adequate Cooling System

The number one rule of cooling is to provide enough radiator capacity for your application. A bigger, thicker core with more surface area will always cool better. When building or modifying a vehicle, plan for the cooling system early and make room for the largest radiator that will fit your application.

Use an Electric Fan

Electric fans are more efficient than mechanical fans because they can be thermostatically controlled and don't rob horsepower from the engine. When selecting a fan, understand the difference between pull and push configurations:

• Puller fans (mounted behind the radiator) are more efficient and are recommended for most applications
• Pusher fans (mounted in front of the radiator) should only be used when space behind the radiator is limited

Always Use the Right Shroud with Your Fan

A fan without a shroud is only pulling air through the area covered by the fan blades. A proper shroud forces the fan to pull air across the entire radiator core surface, dramatically improving cooling efficiency. Never run an electric fan without a full shroud, or you are wasting up to 50% of its potential.

Consider Airflow and How the Radiator Uses It

Airflow through the radiator is critical. Make sure air can flow freely through the core without obstructions. Consider the vehicle's front-end design, grille openings, and any components that may block airflow. Seal gaps around the radiator so air is forced through the core rather than bypassing it.

Use Proper Water Pump Pulley Ratio

The water pump must spin fast enough to circulate coolant effectively. The ideal setup is to overdrive the water pump by 30–35% over crankshaft speed. This means the water pump pulley should be smaller than the crankshaft pulley. Too slow and the coolant doesn't circulate fast enough; too fast and the pump can cavitate, creating air pockets that reduce cooling.

The Pressure Cap Matters

Every pound of pressure raises the boiling point of coolant by approximately 3°F. A 16-pound pressure cap raises the boiling point to approximately 268°F, providing a significant safety margin. Always use the correct pressure cap for your system. Do not exceed 18 lbs for Griffin radiators.

Understand Operating Temperatures

Many enthusiasts panic when they see temperatures above 180°F, but normal operating temperature for most engines is between 180–210°F. Modern engines are designed to run in this range for optimal efficiency, emissions, and longevity. Temperatures consistently above 220°F indicate a problem that needs attention.

Always Use a Thermostat

Never remove the thermostat thinking it will help cooling. It won't. The thermostat regulates coolant flow to ensure the engine reaches proper operating temperature quickly and maintains it consistently. Without a thermostat, coolant flows too quickly through the radiator and doesn't have enough time to transfer heat. This actually makes the engine run hotter, not cooler.

Protect Your System with the Recommended Coolant

For street-driven vehicles, always use a 50/50 mix of quality antifreeze/coolant and distilled water. The antifreeze provides corrosion protection, lubrication for the water pump, and freeze/boil-over protection. Never use tap water. The minerals and chemicals in tap water cause scale buildup and accelerate electrolysis.

Spend Money Wisely

If you're having cooling problems, start with the cheapest and simplest fixes first before investing in expensive upgrades. Use this checklist in order:

• Check coolant level and condition
• Inspect and replace the thermostat
• Check for air pockets in the system
• Verify the fan and shroud are working properly
• Check water pump pulley ratio
• Inspect hoses and clamps for leaks
• Consider upgrading to a higher-capacity radiator