Contrary to popular belief, the modern sports car engine is more similar to the one that you’d find in the average driver’s car. While a sports-tuned engine is designed for high performance and high speed as opposed to efficiency, many of the engineering elements are based on the original equipment manufacturer engine schematic. The difference mainly comes from the components used, precision engineering to internal parts structure, and multiple performance accessories that help deliver the enhanced power to the ground.
In the next few paragraphs, we’ll explain some of the qualities of a sports car engine, and how these attributes are eventually infused into the car, truck, or SUV you drive around town daily.
Breaking Down the Basics of an Internal Combustion Engine
To understand the differences between a sports car engine and a regular engine, it’s important to break down the basic components that make up a modern combustion engine. Essentially, both types of engines have 3 major sections including:
The Block (or bottom end): The engine block is the main component of any combustion engine. This is the bottom end or bottom assembly of an engine that holds the crankshaft, connecting rods, pistons, combustion chamber, and the oil pan. Most engine blocks are configured straight or in a V-shape. The camshaft sits on top of the block and connects to cylinder heads.
The Cylinder Heads: Bolted on top of the engine’s block are the cylinder heads (or cylinder head in some cases). The cylinder head is comprised of multiple individual components such as intake and exhaust chambers, valves, valve springs, pushrods, and other hardware. To keep oil contained inside the cylinder heads so all moving parts are lubricated, valve covers are installed.
Fuel Delivery System: Bolted on top or to the side of cylinder heads is the fuel delivery system. This is either a fuel injection system or a carburetor (in older engines). The fuel system is where fuel and air are mixed into vapor, then sent into the cylinder heads, and eventually into the combustion chamber located in the engine block. A fuel system can be assisted by power-adding components such as a supercharger or turbocharger.
Understanding the Goals of Each Type of Engine
The modern performance engine is engineered for optimal horsepower or torque. Horsepower is the rate at which work is accomplished, while torque is measured in pound-feet or how much "twisting force" is applied to complete a task. A modern ‘daily driver’ engine is optimized for efficiency. How each type of engine accomplishes their goals is what typically indicates the differences between the two.
How a Regular Engine is Engineered for Efficiency
Your daily driver has a powerplant (the engine) that needs to be efficient for multiple reasons. First is the need to comply with federal fuel efficiency and emissions standards. The modern regular engine is often assisted by multiple computer-operated systems that adjust the fuel and air delivery, ignition timing, and even application of power through the transmission to comply with these mandates.
Internal components of a regular engine are usually built for longevity, made from stronger metals that weigh more, and are designed to operate with lower revolutions per minute to extend the lifespan. The fuel system is likewise engineered for efficiency and usually does not include a performance adder. However, new engine technology is infusing smaller engines with turbochargers.
How a Performance Engine is Engineered for Power
To create optimal power in a sports car engine, performance car engineers will fine-tune individual components of the engine. To best express this concept, let’s examine each of the 3 main sections all combustion engines have, and the changes made to each for increased power.
The Block: The engine block of a performance engine is usually made from light-weight materials — aluminum in most cases. The crankshaft is made of durable steel to withstand the high revolutions produced by these motors and with connecting rods and pistons usually made from aluminum or in some cases, composite materials. Most performance engines also have higher compression ratios inside the combustion chamber. To create higher compression, pistons or piston rings are adjusted to create a tighter seal, and the cylinder head gasket on top of the block and under the cylinder head is adjusted.
The Cylinder Heads: If you ask most performance mechanics, they’ll tell you the secret to engine power exists in the cylinder heads. In this instance, performance-based engines have highly customized intake and exhaust ports that help to expedite the flow of fuel and exhaust through the cylinder heads. Performance cylinder heads also have lighter-weight components, in some cases made from titanium to ensure they can hold up against the added power created.
Fuel Systems: If you make adjustments to the bottom end and cylinder heads to create more power, you need to get the fuel there efficiently. This is the job of the fuel system. By adding a turbocharger or supercharger, air and fuel are being forced into the engine, which allows it to burn more fuel and thus create more horsepower.
The key to efficient power is making changes to all three areas that work together in harmony. Engineers usually spend thousands of hours in research and development to find that perfect balance between optimal performance and engine destruction.
For example, the most powerful combustion engine on the planet is found in the modern day NHRA Top Fuel Dragster. This 500 cubic inch engine is similar in many ways to the Hemi engine found in a Dodge 2500 Ram Turbo Diesel Pick-Up. Both have a similar style V8 block, both have hemispherical cylinder heads, and both have a power adder. However, the internal parts of the dragster engine are all specialized, the engine doesn’t burn diesel, but a 90/10 percent ratio of nitromethane and methanol. Additionally, the engine has a fuel efficiency of 60 gallons per mile. That’s not a type-error — it burns 15 gallons per 1,000-foot run down a drag strip. The Top Fuel engine produces slightly more than 11,000 horsepower, while the pick-up turbodiesel is good for about 450 ponies.
As you can see, there are several differences between a sports car engine and a regular engine. One important similarity they have is the need for all of the moving systems to work together efficiently. The fuel system needs to be tuned to the cylinder head configuration, which needs to supply fuel efficiently to the combustion chamber inside the block. They all require routine service and maintenance, and each has an expected lifespan. When routine service is completed as recommended in both types of engines, the car will last longer and allow you to enjoy driving it to its full potential.