Products to Compare (max of 3)
Compare These Parts

Car Cooling System Components

Add Article To List

The purpose of your cooling system is to allow the engine to warm up to the required operating temperature as rapidly as possible and continue to maintain that temperature under all driving conditions. The cooling system should be able to do this when ambient temperature is as low as -30F and as high as 110F.

The peak combustion temperatures on an engine cycle can range from 4000F to 6000F and average between 1200F and 1700F. Continued temperatures as high as this would damage or weaken engine parts if the heat were not removed.

In a conventional cooling system the coolant flows through the block first, through the heads, then after the thermostat opens, through the radiator. Low-temperature coolant leaves the radiator from the outlet and is then pumped back through the engine block where it absorbs heat and continues to re-circulate.

The coolant temperature will increase as much as 15*F as it passes through the engine, and then cools back down as it continues to cycle through the radiator. The flow rate may be as high as one gallon per minute per horsepower depending on your water pump and pulley ratio.

The Thermostat

The thermostat's function is to control the minimum operating temperature of your engine. It’s typically designed as an encapsulated wax-based, plastic pellet heat sensor that will swell as heat increases. The temperature rating on the thermostat will indicate the temperature at which it should begin to open. Typically it’s fully open 20F higher than its rated temperature. For example: a thermostat rated at 180F is fully open at 200*F.

The Pressure Cap

The cooling system is pressurized in order to raise the boiling point of the coolant. The boiling point will increase by about 3F for each pound of increase in pressure. At atmospheric pressure, water will boil at 212F. Under 15psi, water will then boil at 257F. With the proper antifreeze/water mixture, the boiling point should exceed 270F when under 15psi of pressure.

The Recovery System

Excess pressure usually forces some coolant from the radiator through an overflow. Most systems connect the overflow to a plastic or steel reservoir to hold excess coolant when the system is hot. When the system cools, the pressure decreases and a partial vacuum forms. This vacuum will then pull the coolant from the overflow back into the cooling system, keeping the system full.

Speedy Tip

If you notice your radiator hose is collapsed when your engine cools, don’t assume the hose is bad. The collapsed hose may be a result of a defective radiator cap. A properly operating cap should draw coolant from the radiator overflow container back into the radiator and not form a vacuum in the system. We also suggest using a spring inside the lower radiator hose to prevent any chance of this happening.

Coolant Mixture

You can check for proper coolant mixture by using a coolant hydrometer, supplied at most any local auto parts stores. This will measure the density of the coolant, which in turn measures the boiling and freezing point of your coolant. The higher the density, the more concentration of antifreeze to water.

It’s recommended to use distilled or de-ionized water with your coolant mix. That fact remains that distilled water may be at an advantage because it does not contain minerals. If the drinking water you mix with contains minerals, over enough time it can lead to deposit build-up that could prevent proper heat transfer. Speedway Motors offers a premium ready-to-use 50/50 antifreeze and de-ionized water blend from Afco, under part number 106100001.

Coolant additives can also help improve cooling by lubricating and eliminating the possibility of bubbles or foaming. Additives like Red Line’s WaterWetter, part number 91015709, have been dyno tested to substantially improve heat transfer and reduce the possibility of corrosion. We also offer great options from both Pro-Blend and Afco.

To learn more about the importance of a fan/shroud with cooling performance and the difference between downflow and crossflow radiators, check out the related articles tab!

Products Featured in this Article

Related Articles

How To Choose A Radiator For Your Car
by Jason Lubken - Posted in Tech
Learn how to choose the best radiator for your vehicle. Our guide covers key factors to consider when selecting an aftermarket radiator for your hot rod, muscle car, or classic pickup.
Looking Beyond the Cooling System for Common Overheating Cures
by Jason Lubken - Posted in Tech
Have a monster radiator but your engine still overheats? We'll show you what to look for beyond the cooling system for common overheating issues.
Does a Fan Shroud Make a Difference?
by Jason Lubken - Posted in Tech
What is the purpose of a fan shroud? Do you even need a fan shroud? Learn why you need a fan shroud to keep your engine cool and at peak performance!
How to Wire Dual Electric Cooling Fans
by Matthew McClure - Posted in Tech
Learn how to wire dual electric radiator fans. Use our dual fan wiring diagram and guide to make sure you properly wire your fans to your thermostat.
Protect Your Radiator With Nomex Honeycomb
by Jason Lubken - Posted in Tech
Tired of straightening damaged fins or replacing your new race radiator? Try protecting it with a sheet of Nomex honeycomb and let it take the beating instead of your expensive radiator.
What to Consider When Choosing an Electric Radiator Cooling Fan
by Pat Orth - Posted in Videos
What electric cooling fan is right for you? This Tech Talk will take you through some key questions to consider when choosing a cooling fan for your radiator.
Electric Radiator Cooling Fan Guide
by Eric McMillan - Posted in Tech
What is the best radiator cooling fan setup? Do you need a pusher or puller style fan? Should you run two fans or one? Our guide has the answers.
Chevy Small Block - Short vs Long Water Pump
by Jason Lubken - Posted in Tech
Small block and big block Chevy engines were designed with two styles of water pumps, short and long. Before you purchase a new pump, it's important to determine which oneyou have.
Single Pass, Double Pass, Triple Pass Radiators; What’s The Difference?
by Jason Lubken - Posted in Tech
Ever wonder what the difference between single, double, and triple pass radiators is? Our radiator guide will no doubt help you determine which works best for your application.
Differences Between Downflow and Crossflow Radiators
by Speedway Tech Team - Posted in Tech
Learn the difference between a downflow and crossflow radiator and what design is suitable for your application.