We all love making power. Most people know a lot about their engines, from its displacement and configuration, to its benefits and shortcomings. However, many don’t look outside of their engine bays to see what other types of configurations are out there. There are various types of engines that convert chemical energy into kinetic energy, and kinetic energy into mechanical energy to get a car moving. Each type has the good and the bad. Since knowledge is power, here are some of the most popular engine layouts used in automobiles today. In the next part, we will get a much deeper look into their characteristics, like cylinder pulse and scavenging, rotating elements, and engine balance.
Text by Bassem Girgis // Photos by Staff and Manufacturers
Perhaps one of the most popular engine configurations, the inline-four can be found in most compact four-cylinder cars. For this layout, the cylinders are arranged in a straight line. The engine usually sits perpendicular to the vehicle, which leaves the engine bay rather roomy. Engine swapping is also made easy with this layout, as it can fit in almost any engine compartment. The inline-four is considered one of the most reliable layouts. It has only one cylinder head, which means less things can go wrong. Things like replacing the spark plugs are a walk in the park, as they sit directly on top of the engine.
Popular in the Subaru and the Porsche community, the Boxer engine features horizontally opposed pistons. Also known as the flat engine, this layout’s pistons move left and right toward each other as opposed to up and down in traditional engines. The unique design reduces the weight on the crankshaft, ensuring all energy is going to good use while providing smooth operation. The packaging also makes for a low center of gravity, which translates into better handling on the road and the track. Maintenance isn’t one of the highlights of this platform due to its wide design. Boxer engine swaps are almost non-existent, as it takes a lot to modify the engine bay to fit the untraditional characteristics of this layout.
Similar to the inline-four only with two added cylinders, the straight-six is most popular in BMW vehicles. This type of engine usually sits parallel to the car in the engine compartment, as opposed to being perpendicular like the inline-four. Aside from the German manufacturer, the straight-six platform can be found as the layout for the legendary 2JZ-GTE engine found in the Toyota Supra and the RB26 in the Nissan GT-R. The way the firing order works with the straight cylinders makes for a great balance while being capable of having a large displacement. The straight-six layout is similarly easy to work on to its younger sibling the inline-four.
The V engine features cylinders shaped like the letter “V.” The cylinders are usually positioned 60- or 90-degrees from each other. The V layout is usually offered in a six-, eight-, 10-, or 12-cylinders. You may have heard about the myth of the V4 engine, which did exist in cars like the Lancia, but the layout never made it far and is almost non-existent. The V layout allows for large displacement and the possibility of going much larger than factory displacements through cylinder boring. This type of engine is known for being durable and compact. V6 engine examples have been swapped into nearly any engine bay, with kits available that facilitate the swap.
Iconic for american muscle vehicles, the V8 is similar to the V6 but with two added cylinders. Although the degree of where the cylinders are positioned may sometimes vary. Like the V6, the V8 is short in length, making it a good swap after some fabrication to fit the width. The result is a large displacement with tons of potential. With two extra cylinders, however, comes more weight. This engine is no lightweight, but it makes it up in performance once you figure out the balance. This type is known for being durable and well-balanced. A better balanced layout would be the V12.
The Wankel rotary engine is similar to all other engines in the fact that it needs air, fuel, and spark to run – but that’s about it. In an attempt to reduce the amount of moving parts, the rotary engine features eccentric rotors that spin around a central shaft. This replaces the traditional crankshaft that moves the connecting rods and the pistons in the cylinders. As the rotor spins in the housing, it receives air, compresses it while mixing it with fuel, then spark enters the equation to create the combustion process. Although the rotary engine was designed to be more reliable than all other layouts, the plans didn’t go accordingly. Overheating, leaking, and oil burning issues gave this layout a bad reputation; however, it still holds a huge fan base in the Mazda RX-7 community.