AIM : To draw the layout of an automobile repair, service and maintenance shop and study the different sections of the layout. DESCRIPTION

DESCRIPTION :

Periodic maintenance check sheet

The check items include the following:

• 
  Basic engine components.
  
• 
  Engine oil
  
• 
  Engine oil filter
  
• 
  Ignition system
  
• 
  Battery
  
• 
  Fuel and Emission Control
  
• 
  Pre- Filter
  
• 
  Water sediment filter
  
• 
  Air cleaner filter
  
• 
  Chassis and Body
  
• 
  Brake pedal, parking brake
  
• 
  Brake pads and discs
  
• 
  Brake linings & brake drums
  
• 
  Clutch
  
• 
  Power steering fluid
  
• 
  Ball joints and dust covers
  
• 
  Tyres and inflation pressures
  
• 
  Lights, horns, wipers
  
• 
  Steering wheel linkage & gear box oil etc.
  

Vehicle Reg No: Job No :

Table 2.3 TRIP SHEET

ROAD TEST REPORT:

1. 
   The road test inspector or the machine makes the road test report after the completion of the maintenance operation.
   
2. 
   This report contains the vehicle reg number, chassis number, job no, date of test etc.
   
3. 
   The parameters to be checked include the following:
   
   • 
     Front side and rear side abnormal noise.
     
   • 
     Steering and brake caliper noise.
     
   • 
     Ilunting, misfiring, sudden stoppage of vehicle.
     
   • 
     Brake condition.
     
   • 
     Wheel and bearing check.
     
   • 
     Pick up of the vehicle.
     
   • 
     Mileage of the vehicle etc.
     

TRIP SHEET :

The trip sheet gives the entire details of the vehicle before and after a trip. The starting km and ending km, time of start and closing of the journey time and the charges per km and also the overall cost of trip is described in the trip sheet.

LOGBOOK :

The logbook of a vehicle gives the details of the vehicle, which will be useful not only for the owner of the vehicle but also to the mechanic who might take the job of vehicle maintenance latter.

The logbook contains the following details:

• 
  Distance covered
  
• 
  Fuel consumption
  
• 
  Average fuel consumption
  
• 
  Best and worst mileage
  
• 
  Total maintenance cost
  
• 
  Running costs
  
• 
  Faults in the vehicle
  
• 
  Likes and dislikes
  
• 
  Date of the previous maintenance report
  

CONCLUSION :

The different statements and records required for the repair and maintenance works were prepared and the uses of records were studied.

Ex.No:3

AIM:

bore of an IC engine and set the tools and rebore the given cylinder

Telescopic bore gauge, Vernier gauge,Micrometer,Test lamp ,Machine clamping tool, bore clamp, telescopic gauge, vernier calipers, ferler gauge, u- clamp and Allen key setting micrometer.

CYLINDER SURFACE:

Normally in the IC engine cylinder wear at the top is maximum and impact scoring mark either thrust axis or crank pin axis to eliminate the scoring required by boring. The measurement of the cylinder wears, taper and ovality by using telescopic gauge. These gauge and vernier callipers can be used to measure the worn out bore.The cylinder ovality and taper should not exceed 0.050mm otherwise u.s.p and blow by will occur Bore dial gauge with setting ring is also used to measure the cylinder taper is high diffcult for the rings to control by blow gases. The recondining that have excessive tapper or out of cylindricity is done by boring or reboring.Generally a cylinder greater than 0.006inches must be rebored and boring is done.

A cylinder that can not be cleaned by boring and it must be done by reboring process boring which rotates a cutting tool in the cylinder to remove the metals.These operation increase the cylinders bore diameter.

• 
  Initially measure the cylinder bore size at 3 points like top, middle and bottom using telescopic bore gauge or vernier caliper.
  
• 
  Set the cylinder bore centre and the font mounted spindle centre by using spring loaded pin arrangement.
  
• 
  After ensuring the boring part is rotated at the exact centre of bore , tight the clamp giving more toque.
  
• 
  Sides should be bored.
  
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  Set the depth of stopper upto b.d.c.
  
• 
  Rebore , then clean the ovality, taper , scoring marks e.t.c
  

• 
  The vertical boring machine is placed on the engine, after it is fixed to the stand.
  
• 
  Boring machine is fixed to the engine clamp and machine clamp.
  
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  The spindle is lifted and to centered to the cylinder which is to be measured and machines using the pin and spring.
  
• 
  The centering pins are introduced into their respective holes and the spring is introduced over them.
  
• 
  The spindle is lowered into the bore and the centering pins are extended by turning the expander knob.
  
• 
  Machine position is adjusted and the centre pins are extended and brought in such that the gap between the pins and the cylinders walls are same.
  
• 
  After fixing the spindle is lifted and the centre pin spring are removed.
  
• 
  The boring tool is now placed in the holder and the nut above the holder is adjusted using Allen key to move the boring tool. Its distance from the centre is measured by tool setting micrometer.
  
• 
  Tool is set the required length according to the next specified bore diameter and tool adjusting nut.
  
• 
  The tool position is fixed using the locker nut on one side, now the motor is started and the gear is engaged for automatic movement of spindle.
  

The IC engine cylinder reboring machine setting and machined to exact size of cylinder bore and tolls are set and cylinder of the given engine is rebored to the next standard size.

To perform the grinding , lapping , valve setting and valve leakage in the given valve

Valve grinding machine,Spanner,Lapping paste

Lapping stick, Cutter seat, compressed air,water and Lathe machine

PROECDURE:

• 
  At first the valve is taken out the valve assembly. Check the valve head for cranking, valve seat for radial run out in the given valve.
  
• 
  If there is a good margin still left over it can refaced and reused thus the correct of proper valve seat cutter assembly with point.
  
• 
  This assembly is placed on the valve seat which is rotated in the cloakwise4 direction. The carbon of dust and radial run out on the valve head is grinded and cleaned by using the valve grinding machine.
  
• 
  Then the lapping paste is applied over the valve face.
  
• 
  To rotate valve and lift it during the lapping, suction cup is attached to the stick is used.
  
• 
  When the lapping seat is important to give a valve reciprocating under a racking motion not continuously rotary movement. Then the valve is removed in the head and paste is applied, thus the process is done.
  

To check up the valve seat and its setting following methods can be employed

• 
  Checking with petrol
  
• 
  Selection on cup method
  
• 
  Compressed test
  
• 
  By blowing compressed air
  

Compressed test: compression test method is used where the air is pumped with help of rubber and the whole unit is kept light over cylinder head. After building of pressure at(15 lbs square inch) wait for a few minutes, there should be no drop in pressure.

• 
  Chamber is fitted with water
  
• 
  On blowing the air. No air bubble should be sealing the water
  

Thus grinding, lapping , setting the valve angle and checking the valve leakage is done

To study the calibration of fuel injection pump for a ulticylinder diesel engine.

• 
  The calibration test is usually carried to check connect quality of fuel is injected for various load and speed condition. the rack of the fuel ump under test should be in no load position when the test bench is started speed is controlled by hand wheel.
  
• 
  Fit the correct rack setting device4 to the injection pump, remove the tapped inspection cover gauge restriction wheel cock is kept closed to avoid the damage to pressure gauge set the rack setting device to zero then connect the flexible supply line to the supply connection build up the required pressure.
  
• 
  By closing the valves, inspect for leakage the pump housing around discharge union, air vents and locking screw. When the counter knob is engaged and start button one electronic tachometer is pressed fuel will cut off the fuel to the test tub. Then the speed of the varied for varying load condition and the corresponding fuel quantity injected is noted and the readings are tabulated.
  

RESULT: Thus the calibration of fuel injection pump for a multicylinder diesel engine is carried out and tabulated.

MINOR AND MAJOR TUNE-UP OF GASOLINE AND DIESEL ENGINES.

Ex No: 6

AIM :

TOOLS AND INSTRUMENTS REQUIRED :

PROCEDURE :

PETROL ENGINE TUNE-UP :

The cylinder bores do wear out after some use. The amount of wear can be controlled to some extent by cleaning the air cleaner, keeping watch on proper working of cooling system and lubrication system, in spite of all this care after 40 to 50 thousand kms in diesel engine and in petrol engine 60 to 70 thousand kms wear is predominant in the liner which you can see when you dismantle the engine for overhauling. From the worn out cylinder bores few more life can be taken by boring the same with boring machine. When using the boring machine, the boring tool will leave very fine line on the bore, which cannot be seen by naked eyes. Presence of these lines of honing is not desirable. To rub these lines, bores are honed, i.e., polished with the help of honing stone fixed in the cylinder hone head. These hones are driven with portable electric hand drill and while working quickly up and down motion are given.