ARIA

ENGINE

7. Check for leakages through valve seat by pour-

ing gasoline on valve head. Gasoline must not

seep past valve seat.

E VALVE SEAT INSERTS:

1. For removing valve seat inserts from cylinder

head use suitable boring machine. Bore old in-

sert thin

(About 0.5 mm thickness)

and then pry

it out.

2. Alternatively use a suitable turning tool to cut an

annular groove into valve seat insert and then

pull it out with a suitable puller. In order to avoid

damaging machined cylinder head mating sur-

face with crank case, place any soft protective

sheet metal under supports of puller.

3. Measure valve seat insert bore diameter in cyl-

inder head.

4. If boring and prying is done carefully without

damaging valve seat insert bore in cylinder

head, fitment of an over size valve seat insert

will not be necessary.

5. Re-machined valve seat insert bore in cylinder

head must be exactly at right angle to cylinder

head mating surface with crank case.

6. All specified dimensions should be strictly main-

tained to ensure proper interference of valve

seat insert in its bore.

7. Clean valve seat insert and its bore in cylinder

head thoroughly.

F JUST BEFORE INSTALLATION:

1. Place valve seat insert in mixture of Methanol

and dry ice for about 20-30 minutes to bring

temperature down to -150ºC.

2. Heat cylinder head to approximately 80ºC in hot

water bath.

3. Install valve seat insert in cylinder head bore

quickly by light hammering

4. Machine valve seat in cylinder head.

G CAM SHAFT INSPECTION

1. Check cam shaft run out at 2nd journal by sup-

porting it on V-block at 1st and 3

journal.

2. Check cam shaft journal dimensions. Record the

readings.

3. Carry out visual inspection of cam shaft for:

•

Overheating of journals, this is indicated by

bluish/ brown colour.

•

Deep scoring marks on journals and cam

lobes

•

Cracks, which should be checked on a mag-

netic crack detector.

4. Check hardness of cam shaft journals and cam

lobes, it should be 47 HRC.