RadiatorRadiators are the heart of a vehicles cooling system, without them there would be no way to keep an internal combustion engine from overheating to the point of catastrophic failure. In this article we will explain the different kinds of radiators, different materials used in construction of them and hopefully everything else you will ever need to know about this very important piece of equipment.Radiators come in all shapes and sizes, depending on the space constraints and requirements of the vehicle it is installed in. A large vehicle used for extreme service such as a tow truck will have a multiple-row high capacity radiator while a small commuter car will have a much smaller radiator with a lot less capacity. While radiators are also available in what is known as “high-efficiency” configurations, they are for the most part built on an industry standard unless specially made or ordered otherwise. There are 2 different styles of radiator used in the automotive industry; cross flow and top flow.Top Flow: As the name implies, a top flow radiator takes in the hot coolant from the engine on the top row of the radiator and cools it as it flows downward to the bottom. Top flow radiators are mostly seen on older vehicles, as they aren’t as efficient at cooling the antifreeze as the newer cross flow design. Top flow radiators tend to be much taller than cross flow ones, which has become a problem in the more aerodynamic vehicles produced today where under hood space it at a minimum.Cross Flow: Cross flow radiators are what is used in today’s vehicles due primarily to space constraints, although they tend to be more efficient as well. The coolant mixture is pumped into the radiator at one end and forced across the radiator by the water pump, utilizing more cooling tubes in the process, thus cooling the fluid more efficiently. These radiators tend to be shorter and wider than the top flow designs.Regardless of which design your vehicle has in it, radiators all work on the same principle, they are basically a large heat exchanger. Hot coolant/anti-freeze mixture is pumped from the engine into the radiator where it is forced into smaller tubes, these small tubes run the width or height of the radiator depending on the design (Top or Side flow). The tubes have small fins attached to them that act as heat syncs, which dissipate the heat through absorption and air flowing across them through the front of the vehicle or by the fan pulling/pushing air through the radiator. The more fins per square inch, the more efficient the radiator is at dissipating the heat and keeping the engine cool.