Cylinder Block
Cylinder Block
The cylinder block along with crankcase and cylinder head form the stator body of automobile engine and support and enclose the moving parts. All static and dynamic loads due to rotation, unbalanced forces of reciprocating masses and torsional vibrations of crankshaft are transmitted to the vehicle frame through the cylinder block. The engine block is also subjected to extreme temperature gradients because of high combustion temperatures inside the cylinder.
The cylinder block is cast as a strong and rigid body and provides smooth (mirror finish) round cylinders for friction-free piston movement, openings for valves and passages for flow of cooling water or coolant.
The crankcase is the base of the engine and supports the crankshaft and the engine. It is supported on the vehicle frame through brackets provided on the crankcase. The oil pan is bolted from the bottom which provides a reservoir for the storage, cooling and ventilation of the engine lubricating oil.
The cylinder head is a separate casting which is bolted to the cylinder block from the top and houses the combustion chamber, valves and spark plug.
The design and shape of the combustion chamber is important is controlling the combustion process. The shape of the cylinder head depends upon the valve arrangement. The general classification is given below.
(i) The I-head engines have valves in the cylinder head and operated by push rods which operate the rocker arms. [Fig. 2.4 (b)]
(ii) In L-head design, both inlet and exhaust valves are on one side of the engine and are operated by a single camshaft.
(iv) The T-head designs have the inlet valves on one side and exhaust valves on the other side; necessitating two camshafts.
References
- Automobile Engineering (Vol. 1 & 2) - K.M.Guptha
- Automotive Mechanics - Joseph Heitner
- Automobile Engineering - Harbans Singh Reyd
- Automotive Mechanics - William H. Course
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