Inside an Engine

Back in the salad days of automobile manufacturing the engine under the hood was something to show off. Musclecars proudly displayed HEMI or BOSS 302. A twin-cam four-banger let you know what it was by the valve cover design, not only showing off the internals of the engine, but also having "Twin Cam" in raised letters on the valve cover. What went on inside the engine was equally important to the operation of the vehicle. The words Hemi, Turbo, or Twin-Cam were often displayed as part of the car's badging or graphics package. To the beaming vehicle owner these badges were a source of pride.

Grocery-Getting Racecars of Today
Pop the hood on most modern vehicles and the engine is sadly covered, usually with a shroud of cheap looking plastic. This sterile presentation gives no clue as to what's going on inside the engine. Even if the engineers had stuffed the engine with multiple camshafts and four valves per cylinder one would never know. The paradox of this cover up is that some of today's grocery getters best horsepower levels reached by top-of-the-line sports cars from a decade ago. Despite these horsepower gains, the bean counters and marketers hide engines with a five-dollar plastic novelty cap.


Beneath the underhood equivalent of 99-cent store day-glo pith helmet that covers a modern engine is the engineering required it takes to convert a bit of gasoline and air into 300 horsepower at the touch of the throttle. Inside that engine are the parts that work together as a whole to accomplish this amazing feat. These are parts that spin and bump together thousands of times per minute and are separated by nothing more than a few thousandths of an inch of motor oil. Taking a look inside an engine can give one a better idea of which parts are which and what does what. Underneath that cover is where the miracle of internal combustion happens.

Cylinder Head
The cylinder head is also referred to as the top end of the engine. The cylinder head contains the intake and exhaust valves as well as the spark plugs. The intake valve opens to allow the fuel-air mixture into the engine. The spark plug sparks the mixture into power. The exhaust valve lets the exhaust out of the tailpipe.

Short Block
The engine block and rotating assembly can be referred to as a short block, or bottom end. The rotating assembly is named as such for it rotates around and around on the crankshaft. Connected to the assembly are the connecting rods and pistons. The pistons work with the cylinder head to draw fuel and air into the cylinder, harness the power of the exploding mixture then expel the exhaust.