A short block is an engine sub-assembly comprising the portion of the cylinder block below the head gasket but above the oil pan. An in-block cam engine includes the camshaft, timing gear, and any balance shafts. Overhead cam engines don't include those parts.
Considering this, what is the difference between a short and long block engine?
TO START WITH ALL ENGINES ARE THE SAME DIMENSIONS, SOME PEOPLE ASK IF A SHORT BLOCK IS SMALLER THAN A LONG BLOCK, THE ANSWER IS No. THEY ARE THE SAME SIZE, THE REASON THEY CALL IT A SHORT BLOCK IS THAT MANY OF THE PARTS ARE LEFT OFF SUCH AS HEADS, ROCKER ARMS, LIFTERS, OIL PAN, ETC.
What are the main parts of an engine?
Let's look at some key engine parts in more detail.
- Spark plug. The spark plug supplies the spark that ignites the air/fuel mixture so that combustion can occur.
- Valves. The intake and exhaust valves open at the proper time to let in air and fuel and to let out exhaust.
- Piston rings.
- Connecting rod.