Car engines are complicated machines that utilize explosive combustion processes to convert fuel into motion, so understanding their basics will give you a deeper insight into how your vehicle functions.
Car engines come in all sizes and configurations, but most modern cars use what is known as a four-stroke internal combustion engine to power their vehicles. All four-stroke engines work by producing power through explosions.
Cylinders
Cylinders are the spaces within an engine where combustion takes place to create power for driving the car forward. Although a car engine may seem complicated at first glance, every driver should familiarize themselves with its key terms to keep their car safe.
At the core of every engine are its cylinders – cylindrical bores within a metal engine block with pistons at their bottom that move back and forth when an explosion takes place. A series of controlled explosions force these pistons up and down during engine operation.
Spark plugs ignite fuel/air mixtures to generate combustion in the cylinders, producing hot gases which push down on the piston and compress gas and air before reigniting again for another explosion that gives energy for moving your car forward. Once compressed again, piston compresses it again before reigniting it for one last time for another explosion which makes your car move. Finally, piston pushes back up again, turning this up-and-down motion into rotating motion which powers a crankshaft that drives all manner of mechanical components that get your car going forward.
Pistons
Pistons are cylindrical metal tubes that fit tightly within the cylindrical holes in engine blocks and move vertically back and forth, similar to upturned cups. Attached at either end are metal rods called connecting rods that connect directly to a crankshaft at right angles – together these elements convert this up-and-down movement into constant circular movement that drives various aspects of powertrain systems like your car’s drive wheels.
On its upswing, the piston draws air and fuel into its combustion chamber through openings in its cylinder head. Once in, spark plug ignites this mixture, producing an explosion that sends it tumbling back down again before exhaust valves open to release burnt gases out the exhaust port – and repeating this cycle hundreds of times every minute! Each cycle generates enough energy to drive your car forward!
Crankshaft
Unto its untrained observer, the engine of your car may seem like a complex maze of metal and tubes, yet what goes on beneath its skin is actually quite straightforward. Fuel, air and spark combine in controlled explosions in each of its cylinders which push pistons up and down, turning crankshafts connected to transmissions which then transmit power directly to drive wheels on your car.
Pistons feature journals (the portions of their shaft that rest on bearings) and throws, which refer to the dimensions of a piston pin that connect to connecting rods that lead to the crankshaft.
Crankshaft journals are precision-machined for optimal performance, featuring offset locations for connecting rod journals and flywheel flange. Furthermore, it features counterweights to help balance out piston movement against rotational energy generated by crankshaft rotation; stored energy then facilitates wheel movement when you accelerate or shift gears while driving.
Cylinder Head
The cylinder head, which serves to close off the combustion chamber from above, is one of the key components in your engine. It contains intake and exhaust ports, fuel injection nozzles, spark or glow plugs and in some engine types even camshafts for combustion chamber closure.
Cylinder heads serve a crucial purpose: housing the combustion chamber – where all of the magic happens! Its shape and size determine how powerful an engine will become.
The cylinder head also houses intake and exhaust valves that open and close at specific times to regulate air and gasflow, with their mating surfaces (valve seats) machined precisely for tight seal. Manufacturers generally build cylinder heads out of cast iron or aluminum; aluminum tends to conduct heat more effectively and conduct it away more rapidly; casting is the more prevalent approach but for high performance applications machining may be preferred as casting uses polystyrene models packed with casting sand which then evaporates as hot aluminum pours onto it – an experience not unlike that found when casting!