Workshop report internal combustion engine mechanics

 Prevents oil and engine coolant from leaking or mixing. Help maintain the pressure of combustion gases.b Intake and Exhaust Ports  The intake and exhaust ports are part and parcel of

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY

NATIONAL UNIVERSITY

WORKSHOP REPORT

INTERNAL COMBUSTION ENGINE MECHANICS

540 Power Exhaust Compress Intake

STATIONARY SYSTEM Overview

(1) Springs close valve; (2) Valve retainer; (3) Rocker shaft; (4) Valve clearance adjuster; (5) Rocker arm; (6) Stud hole; (7) Threaded hole for bolting rocker cover to cylinder head; (8) Intake ports; (9) Pushrod; (10) Housing for thermostat

2 Components:

a) Head Gasket

 Located between the cylinder head and the engineblock

 Prevents oil and engine coolant from leaking or mixing.

 Help maintain the pressure of combustion gases.b) Intake and Exhaust Ports

 The intake and exhaust ports are part and parcel of thecylinder head

 Channel air through the passages in the cylinder

 The exhaust ports connect to the exhaust manifold todrive out the gases

c) Cylinder Head Valves

 Valves close and open to let in or block the entry of airand fuel into the combustion chamber

d) Cylinder Head Combustion Chamber

 This is where the air/fuel mixture burns to produce thepower to move a vehicle.

 The chamber comprises the cylinder head with its portsand valves, the cylinder and cylinder walls, and thepiston with its connecting rod

e) Spark Plugs

 Found in gasoline engines

 They convey electricity to the combustion chamber toignite the air/fuel mixture

f) Fuel Injectors

 In diesel engines: the injectors push fuel into thecombustion chamber directly, with the help of theinjection pump.

 In petrol engines: the injectors use an indirectmechanism for the same function

g) Cylinder Head Camshaft

 Works the opening and closing of the valves in a timedmanner

 The crankshaft drives the cylinder head camshaft using

through multiple oil galleries, lubricating all importantcomponents.]

2 Types Of Cylinder Block

(5) Water Jacker; (6) Block Mounts; (7) Crankshaft Housing

c) Opposed Engine or Boxer Engine Cylinder

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VALVETRAIN SYSTEM

I Classifications:

II Valve mechanism:

- A valve mechanism is a group of components thatopens and closes the intake and exhaust valve in thecylinder head

- There are various types of valve mechanism, depending

on the position and the number of the camshafts.+ DOHC ( Double Overhead Camshaft )

+ OHV (Overhead Valve

+ Timing chain: the rotational movement of thecrankshaft to the camshafts

- VVT-i system: use a computer to optimally control theopening and closing timing of the intake value

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 Some survey pictures at the factory:

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III Piston and cranktrain system:

- Piston: moves vertically in the cylinder, as a result ofthe pressure generated by the combustion of the air –fuel mixture

- Crankshaft: changes the linear movement of the pistoninto rotational move a connecting rod

 Diesel D9:

Piston: Bowl piston, full skirt ( 1 horizontal piston )

4 piston rings: 1 oil ring

Component rod: cross section

 Diesel 4 cylinder:

Piston: bowl piston, partial skirt

3 piston rings: 1 oil ring, 2 compression ringsConnecting rod: cross section

 V8 engine:

Piston: bowl piston, partial skirt

3 piston rings: 1 oil ring, 2 compression ringsConnecting rod: cross section

POWERTRAIN SYSTEM I/ Components

_Piston conducts the reciprocating movement in-cylinder

_Connecting rod converts the reciprocating movement of small end to the rotary movement of big end and impact to crankshaft_Then, crankshaft produces the effective torque

_Flywheel stores the rotary movement of crankshaft to inertia energy and contributes steady rotating

III/ Pictures from the factory:

LUBRICATION SYSTEM AND COOLING SYSTEM

- Besides, we had a clue to state SYM T880 being a dry sumptype since this engine is located inline We are not sureabout this data being right or wrong

- Fresh lubricant will be stored at oil galleries to supply forfriction contacts Following this, oil might return thecrankcase and the process takes place in circulation mode.

7 Some practical pictures from workshop.

- Oil pan

s

- Oil filter

- Dipstick

II Cooling system

- We surveyed 3 engines namely SYM T880 (SI), Hyndai (CI)and KIA (CI - I4)

1 Type of cooling system.

All these engines are applied liquid cooling system for ensuringstable temperature of engines, particularly forced circulationcooling system

1 - Radiator, 2 - Thermostat, 3 - Water pump, 4 - Engine, 5 - Fan

6 - Upper pipe, 7 - Lower pipe, 8 - Bypass

Note:

- Red arrow: when engine is stay at warming operation (close)

- Blue arrow: cooling engine (open)

4.2 Inline by-pass type

1 - Radiator, 2 - Thermostat, 3 - Water pump, 4 - Engine, 5 - Fan

6 - Upper pipe, 7 - Lower pipe, 8 - Bypass

Note:

- Red arrow: when engine is stay at warming operation (close)

- Blue arrow: cooling engine (open)

5 Operation

5.1 Bottom by-pass type

In close state (warming), it means that thermostat allows hotcoolant flowing back engine after passing bypass and prevent

coolant from lower pipe moving to water pump This operationoccurs at less than 80 Degree Celsius in thermostat At this time,fan does not run.

In open state (cooling), everything takes place oppositely Thethermostat prevents hot coolant from bypass to water pump andlet cool coolant from radiator move to water pump Besides, thefan is in state of working

5.2 Inline by-pass type

In close state, valve in thermostat close and prevent hot coolantfrom coming radiator, therefore it come back engine to warm

In open state, the valve open and hot coolant move to radiator totransfer heat to surrounding by a fan The coolant become coolerand move to water pump afterward However, there is not anybypass valves so the little amount of hot coolant still flows towater pump