69 the guide to all currently available engine configurations
the guide to all currently available engine configurations
By Vukasin Herbez on 2018-07-06 17:36:16
Even though the industry has come a long way since the first cars rolled off the assembly lines, some of the principles and patents are still basically unchanged. One of those things is the engine itself. Despite immense improvements in materials, craftsmanship, metallurgy, and engineering, modern engines use the same internal combustion cycle as their counterparts from the early 20th century. Over the years, engineers developed numerous engine configurations in order to explore the limits of engine mechanics and physics as well as to make motors more powerful, durable and better suited for various purposes. Today, we will show you all engine configurations that are currently in production and if you own a car, any car, you can find your configuration on this list. So, let‘s get straight to it.
1. Inline Three-Cylinder Engine
The inline three engine configuration was invented years ago but it wasn´t widely used until recently when most major car manufacturers started producing those diminutive engines and installing them into smallest economy cars. The inline three engine is characterized by the fact it has an engine block with three cylinders positioned in a straight line. All inline three engines are small displacement units, ranging from 800 ccs to 1.5-liter units. This also means that they are low on power but in modern applications, three-cylinder engines are paired with turbochargers so they provide sufficient amount of grunt.
The advantages of inline three-cylinder units are small dimensions and weight which is perfect for small, economy cars and urban runabouts. Small dimensions mean that they can be positioned deep inside of the engine bay making the center of gravity low and improving driving dynamics. Since there are only three cylinders to move around, those engines are happy to rev and can even provide modest performance. Also, small displacement means better fuel economy in normal driving conditions which is also helpful.
However, since there is an uneven number of cylinders they are not as smooth as some other configurations and engineers tried to sort it with crankshafts with counterbalance. Also, the small displacement and small power means that the torque is pretty low and under a lot of stress, three-cylinder engines show all the disadvantages of this configuration.
2. Inline Four Cylinder Engine
The inline-four engine is the most common engine configuration in the world. It has been in use since forever and it is fairly compact so it can be placed transversally and longitudinally in the engine bay. Almost all of the world‘s car manufacturers use four cylinders in some of their models and 70% of cars produced at this very moment use inline four as the engine of choice. Inline fours can range from as little as 1.1 liters to 3.0-liters in displacement and can be fitted with turbochargers or superchargers. Also, most of the diesel engines on the market are inline four units.
Since this configuration offers decent power, compact dimensions as well as moderate fuel economy, it is commonly installed in standard everyday models. The disadvantages are basically just not as smooth power delivery compared to bigger engines but modern units are very well designed and there are really no major issues with this concept. That is why it is so popular all over the world.
3. Inline Five-Cylinder Engine
Compared to other inline engines, inline five is a quite rare item since it is used only by Audi and Volvo at the moment. The inline five is characterized by straight five cylinder layout which makes those kinds of engines longer than standard inline fours and somewhat problematic to install transversally.
The advantages are more torque and distinctive growling engine sound and both in Audi and Volvo applications, the engineers paired them with turbochargers making these inline five-cylinder engines quite powerful and fast. The biggest disadvantage is the fact that the number of cylinders is not even and the crankshaft requires a counterbalancing. Also, the maintenance is a bit more expensive than for four-cylinder units.
4. Inline Six Cylinder Engine
The best inline engines are straight-six units which feature a long engine block with six cylinders in a row. The inline six concept is very old and dates back to the early 20th century. Even though there were a few cars with inline six engines mounted transversally, the sheer length of the unit allows only one configuration and that is to be mounted longitudinally. The displacements are generally higher than those of inline four or five cylinders and straight six engines range from 2.0-liters to just above 3.0-liters.
The advantages of inline-six engines are a smooth and quiet operation, more power and torque as well as durability. Six cylinders in a straight line can provide torque earlier in the rev range making them desired units for installation in upscale sedans. The smoothes of inline sixes proved to be a great match for diesel fuel which resulted in very powerful motors which combined fuel efficiency with enormous torque. Due to bigger displacement and two more cylinders than standard inline four, gasoline engines tend to use a bit more fuel.
The disadvantages of straight six engines are all connected to the cost and availability. This configuration requires precision engineering as well as casting of long block, cylinder heads, crankshaft and camshafts which is expensive and just a few companies like BMW make straight six engines at the moment. Also, due to the length of the unit, it is possible only to mount it longitudinally which limits the numbers of applications.
5. V6 Engine
The V engine configuration starts with V6 even though there were smaller V4 engines produced in the ‘60s and ‘70s, but the concept never caught up with the public. The V6 is called that since it features a V-shaped engine block with two banks of cylinders under an angle, usually 60 or 90 degrees between one another. Two rows of cylinders each have separate cylinder heads but they share a crankshaft, obviously. The V6 configuration was invented in the early 20th century but first perfected and produced in significant numbers by Italian company Lancia in the ‘50s. After that, most of the world‘s manufacturers designed and used some form of this engine configuration. The V6 engines are produced as gasoline or diesel units and can be found in various types of cars, from ordinary sedans and SUV models to even latest high priced supercars. Their displacement starts from 2.5-liters and goes all the way to 4.0-liters.
The advantages of V6 units are the compact size and high power, due to bigger displacement. Since V6 consists of two banks of three cylinders it is fairly compact and square which means it can be placed practically anywhere. So there are front, mid and even rear engine V6 cars with motors positioned longitudinally or transversally. Due to bigger displacement, V6 provides more power than smaller units although torque ratings are generally lower than on comparable straight six engines. Also, due to the fact that the crankshaft is relatively short, V6 engines can achieve high rpm and are often used for racing cars.
The disadvantages include lack of smoothness and vibrations since a V6 requires counterweights on the crankshafts for balancing. The reason for that is the fact that the V6 is formed from two separate three-cylinder units which have an uneven number of cylinders and share the same crankshaft.
6. V8 Engine
The V8 engine is probably the best engine configuration if you are looking for a balance between smooth running, power, torque and dimensions. As all popular engine concepts, it has been around for decades and is still perfected with each new generation. V8 consists of a V-shaped block with two banks of cylinders (four each) sharing the same crankshaft. It is fairly bigger than V6 which demands that it must be installed longitudinally. The V8s start just below 4.0-liters and go all the way to 7.0-liters of displacement even though that some US manufacturers produced even bigger eight-cylinder engines in the ‘60s and ‘70s. Most of the V8 engines produced are gasoline powered but there are significant amounts of diesel V8 units, mostly for big trucks, machines, and large SUV models.
The advantages of a V8 are numerous since that engine produces high power, a lot of torque and still is a very smooth unit which makes it perfect for dozens of applications. More than any other car engine, V8 is used to power boats, machines, and airplanes and over the years, almost all big car manufacturers produced their V8 units. Due to relatively compact dimensions, V8s can be found in luxury models as well as in sports cars or heavy machinery. The V8 engines are also well known for their distinctive rumble and regardless of the make or displacement, they all sound very good under full throttle and even at idle.
The biggest disadvantage is fuel consumption since a V8 needs more fuel than straight six or V6 engine. Modern V8s are equipped with cylinder deactivation systems which shut down a couple of cylinders when there is no need for full power. This system helps achieve better mileage.
7. V10 and V12 Engines
One step above the widespread V8 engines are V10 and V12 units. The basic concept is the same but those motors have two or four more cylinders in V shape divided in two banks of five or six. As the V8, V10 and V12 are quite old configurations but they are rarely used due to specific requirements in production and expensive production process. That is why those engines are only used in high end and luxury models and supercars. V10 and V12 engines have plenty of power, big displacement and smooth running, especially V12 motors which are like two smooth straight six units with the same crankshaft.
The main advantages of V10 and V12 motors are lots of power, big torque figures and smooth and quiet running. On the other hand, the biggest disadvantages are the enormous costs of running and maintaining those kinds of engines as well as poor fuel economy. Simply, high-end technology, materials, and big displacement ask for wealthy owners since V10 or V12 units are not for ordinary cars by any means.
8. Flat Six and Flat Four Engines
Flat six or flat four engines are a very interesting engine configuration currently used only by Porsche and Subaru. Flat or boxer engines have horizontally opposed banks of cylinders with a 180-degree angle between them. The pistons share the same crankshaft and move back and forth in opposite direction resembling the arm movements in a boxing match. The flat four engine has been around for quite some time and original VW Beetle used it in the late ‘30s. Over the years, it was used by numerous manufacturers and even in motorsports but remain the signature engine choice for Porsche and Subaru which fully used the specific features of this concept.
The biggest advantage of flat six and flat four engines is smoothened and lack of any vibrations. The reason is quite simple, the 180-degree angle between the cylinders eliminates any unwanted vibrations and balances the engine. Also, since the engine itself is pretty low compared to vertically positioned inline or V type engines, it has a low center of gravity which immensely helps stability and road holding of the vehicle. Also, due to smooth running, boxer engines can achieve high rpm and power.
The disadvantages of the horizontally opposed engine are the dimensions of the unit and boxer motors are much wider than any inline or V type engine making them pretty hard to fit most engine bays. That is why Porsche and Subaru design their cars around the engine since it requires precise measuring and construction of the drive train in order for them to fit. On the other hand, repairs and maintenance of the flat six or four engine can be a bit difficult and require specific tools. Also, the rebuilding of the flat six or four unit is demanding since the engine block is made from two big castings and this process requires a lot of precision work and most shops are not familiar with the process.
9. W12 Engine
You must think that we have made and mistake and wrote ´W´ instead of ´V´ but no, the W12 engine is a real motor and despite it only being used by a few car manufacturers at the moment, it has interesting features and technology behind it. The W12 is basically made out of two narrow-head V6 engines put together sharing the same block and crankshaft. The two V engines combined in one assembly makes a W-shaped engine block hence the name.
The W12 engine was used in military industry but recently became the preferred engine of luxury Audis and Bentleys which implemented that concept for their flagship models. The advantage of the W12 configuration is the compact size which is roughly the size of a big V6 or a smaller V8 engine but with 50% more displacement, cylinders and power. However, the extremely busy construction with four rows of cylinders, eight camshafts, and numerous other components makes the W12 expensive to produce and maintain, similar to more conventional V12 engines.
10. Wankel Engine
The Wankel or rotary motor is an advanced concept of an internal combustion engine which features construction of the engine block and rotating cylinders which is totally different from all other engine configurations. So far, all engine configurations use pistons which move up and down (or left and right) inside the engine block. The Wankel engine has a rotor (rotating piston) inside the block which rotates consistently in one direction. This makes Wankel engines not only much simpler in construction but more efficient in terms of thermodynamics. In regular engines, a piston moves in a straight line accelerating rapidly and stopping abruptly in short distance. In a rotary engine, a piston moves in a circle which is a far superior way. Over the years, lots of manufacturers experimented with Wankel engines but only Mazda managed to produce this motor in significant numbers installing it in popular RX7 and RX8 sports cars.
The advantages of the Wankel motor are pretty significant and rotary engines can produce higher power from smaller displacement, achieve higher RPMs, they are much simpler in construction than conventional units, much lighter and compact which greatly affects the overall performance of the car. Mazda even managed to win the legendary 24 Hours of Le Mans endurance race with Wankel-powered prototype proving the efficiency and performance of this engine.
On the other hand, disadvantages of the Wankel engines are pretty big as well and due to the fact that compression of the engine is based on edge of the triangular rotating piston and a microscopically thin layer of oil, even the slightest drop in oil pressure can cause engine failure. Wankels were always known as not exactly durable engines and they cannot achieve high mileage, at least not without a total rebuild. Even though the Wankels have hp per liter ratio and they can be turbocharged, the high revving nature of the engine means it has modest torque output. Despite all significant advantages, the industry never found the way to make Wankels durable enough for wide use in regular passenger cars.
11. Hybrid Engines
The latest and pretty popular configuration is hybrid engines and this is simply the combination of the standard gasoline unit with one or more electric motors and battery pack. In the last several years, there came numerous hybrid models on offer, starting from small city cars to luxury sedans equipped with big and powerful gasoline engines and a pair of electric motors. The basic principle behind the hybrid is simple the car uses the gasoline engine for starting, high speed cruising or overtaking, but during low-speed city driving, electric motors take over and produce zero emissions. When a car is using its internal combustion motor, batteries are recharged which helps in to maintain the level of electric power needed for operation.
Some modern hybrids have advanced software which monitors the car‘s operation and calculates driver‘s intentions so they can engage electric power in various operation modes so the performance, braking, road holding and overall economy is improved. The switch between electric and gasoline power is so smooth that even the driver cannot tell the difference.
The biggest advantage of the hybrid systems is, of course, the fuel economy and zero emissions, especially while driving in urban areas which helps the environment. Using the electric motors will also keep the gasoline engine in perfect condition for longer.
On the other hand, hybrid cars are all more expensive than similar gasoline or diesel powered models. The construction of the hybrids requires an additional pair of electric motors and a big battery pack which means that hybrids are much heavier than similar non-hybrid cars. More weight translates to poor performance and even higher consumption when in gasoline mode which makes the hybrid drivetrain obsolete and counterproductive. Over the years hybrids became the pretty popular choice for environmentally cautious buyers but the overall efficiency of the concept is still unproven, especially knowing that batteries are pretty tough to recycle and notoriously hazardous to produce. However, most of the car buying crowd is staying away from hybrids mainly because of the high prices and not great resale value. The best way to have fuel efficient and environmentally friendly vehicle is to buy a fully electric car or any of the modern diesel which is capable of returning great mileage.
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