ENGINE CONSTRUCTION AND CLASSIFICATION

ENGINE PARTSCylinder blockCylinder headCrank casePiston Piston ringsGudgeon pin Intake and exhaust valveCamshaftCrankshaftTiming gears

CYLINDER BLOCK Cast iron Aluminum alloyWater jacket

CYLINDER BLOCK

LINER Cast steel Cast iron Press fit

CYLINDER HEAD Aluminum alloy Cast iron (combustion chamber)hemisphere

CYLINDER HEAD

VALVE OR TAPPET CLEARANCE

Spring retainer

CRANK CASE Cast iron Cast steel

CRANK CASE

CRANK CASE

PISTON Aluminum alloy Cast iron Gudgeon pin

Forged steel Case hardened steel

PISTON RINGS Cast iron Pressed steel alloy Compression ring Oil ring

CRANK SHAFT Forged steel Cast steel

CAM SHAFT Forged steel Cast iron and cast steel Push rod

• Forged steel• High speed (X)

CAMSHAFT

SOHC AND DOHC Forged steel Cast iron and cast steel

CONNECTING ROD Forged steel Aluminum alloy

CONTD.

VALVES Forged steel Cast alloy Opening Camshaft Closing spring

DESMODROMIC VALVE OPERATION Used by Ducati

GEAR TIMING Timing belt drive Timing gear drive Timing chain drive

BELT TIMING

FLYWHEEL Cast iron

ENGINE CLASSIFICATION

No of strokes per cycle(Two or Four)

Type of fuel burned Method of ignition Firing order Reciprocating or rotary

No of cylinders

Arrangement of cylinders

Arrangement of valves and

valve trains

Type of cooling

POSITION ARRANGEMENT & NUMBER OF CYLINDERS

Single Cylinder

Inline Cylinders

V Engine

‰Opposed Cylinder Engine

‰W Engine

‰Opposed Piston Engine

‰Radial Engine

ARRANGEMENT OF CYLINDERS

ARRANGEMENT OF CYLINDERSSingle cylinder:

Engine has one cylinder and piston connected to the crankshaft.

‰In-Line:

Cylinders are positioned in a straight line, one behind the other along the

length of the crankshaft. Number of cylinders may vary

from 2 to 11 or even more. In-line four-cylinder engines

are very common for automobiles. In-line engines are

also referred to as straight such as straight six or straight

eight

.

ARRANGEMENT OF CYLINDERS

V Engine:

Two banks of cylinders at an angle with each other along a single crankshaft.

The angle between the banks of cylinders is usually within 60-90. V engines

have even numbers of cylinders ranging from 2 to 20 or more. V6 and V8

are the common engines with six and eight cylinders respectively.

Opposed Cylinder Engine:

Two banks of cylinders opposite to each other on a single crankshaft. These

are mostly used in small aircraft and some automobiles with an even number

of cylinders from two to eight or more. These engines are also called flat

engines such as flat four.

Boxer engine

ARRANGEMENT OF CYLINDERSW Engine:Similar to that of V engine except with three banks of cylinders on the

same crankshaft. This type of arrangement has been used in some racing cars.

Opposed Piston Engine: Two pistons in each cylinder with the combustion chamber located

centrally between the pistons. A single-combustion process causes two power strokes at the same time, with each piston being pushed away from the center and delivering power to a separate crankshaft at each end of the cylinder Engine output is either on two rotating crankshafts or on one crankshaft incorporating a complex mechanic linkage.

ARRANGEMENT OF CYLINDERSRadial Engine:

Engine with pistons positioned in a circular plane around the central

crankshaft. The connecting rods of the pistons are connected to the

crankshaft through a master rod. A bank of cylinders on a radial engine

always has an odd number of cylinders ranging from 3 to 13 or more

Many medium-and large-size propeller-driven aircraft use radial engines.

For large aircraft, two or more banks of cylinders are mounted together,

one behind the other on a single crankshaft, making a powerful and

smooth engine.

THREE CYLINDER ENGINE

FOUR CYLINDER ENGINE(INLINE)

4 cylinder in line.mp4

FOUR CYLINDER ENGINE(V TYPE)

4 cylinder v type.mp4

FOUR CYLINDER ENGINE(OPPOSED)

• Balancing• Less

inertia• Subaru• Aerodyna

mic drag

FIVE CYLINDER ENGINE(INLINE)

5 cylinder.mp4

SIX CYLINDER ENGINE

8 CYLINDER ENGINE(V TYPE)

8 cylinder.mp4

W TYPE

RADIAL TYPE

ROTARY(WANKEL TYPE)

ROTARY(WANKEL TYPE)

Mazda RX7 and RX8 Rotary engnie

VALVE LOCATIONS

‰

Valves in head (overhead valve), also called I-head engine.‰Valves in block (flat head), also called L-head engine. Some historic

engines with valves in block had the intake valve on one side of the cylinder, and the exhaust valve on the other side. These were called T-

head engines.‰One valve in head (usually intake) and one in block, also called F-head engine.

VALVE LOCATIONS

VALVE TRAINS

Times the opening and closing of the cylinder valvesEnsures opening and closing is kept in sync

TYPES OF VALVE TRAINS

TYPE OF COOLING

Air Cooled‰Liquid Cooled/Water Cooled

NO OF STROKES

‰Four Stroke Cycle Experiences 4 strokes of the Piston movements over 2 revolutions of the crankshaft‰Two Stroke Cycle Experiences 2 strokes of the Piston movements over 1 revolution of the crankshaft

FUEL USEDUsing volatile fuels like gasoline, alcohol, kerosene �Using gaseous fuels like natural gas, biogas

�Using viscous fuels like diesel �Using dual fuel methanol (suction stroke) + diesel (comp. stroke) –CI

Engine–gasoline + alcohol (gasohol)

METHOD OF IGNITION

Spark Ignition: An SI engine starts the combustion process in each cycle by

use of a spark plug. In early engine development, before the invention of the electric spark plug, many forms of

torch of torch holes were used to initiate combustion form an external flame.‰Compression Ignition: The combustion process in a CI engine starts when the air-fuel mixture self-ignites due to high temperature in the combustion chamber caused by high compression .

FIRING ORDER

Firing order 1 3 4 2

4 cylinder in line.mp4