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1.5L REVOTORQ BS VI ENGINE
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Inspection
A. Cylinder Head
Checking Cylinder Head Mating Surface
1.
Using a straight edge and feeler gauge, check
evenness of cylinder head parting surface with
crank case. If unevenness exceeds specified
values, replace cylinder head.
2.
Permissible unevenness of cylinder head
mating surface-0.040 mm
(Length wise) /
150mm.
3.
Permissible unevenness of cylinder head
mating surface-0.040 mm
(Cross wise) /
150mm.
4.
Overall flatness 0.1mm
NOTE
Cylinder head top and bottom surface re-
machining in service is not permitted.
B. Valves
1.
Check valve leakages by pouring gasoline on
valve head. Gasoline must not seep past valve
seat.
2.
Valves with burnt heads, excessive scoring and
wear on stem should be replaced.
3.
Check valve seat run out with respect to valve
stem. If it exceeds specified limit replace valve.
No attempt should be made to straighten bent
valves.
4.
If valve is free from any other defects except
worn out seat, then only it can be rematched on
valve grinding machine as follows:
Clamp valve on grinding machine jaws as
close as possible to valve head.
Adjust grinding angle on graduated scale to
achieve correct valve seat angle.
Feed valve slowly towards grinding wheel
until wheel just touches valve head.
Grind at low feed until valve seat is just clean
all around.
NOTE
After grinding, valve head thickness should not be
less than 0.85 mm.
C. Valve Guides
1.
In case of valve stem sticking in valve guide
bore or Excessive clearance between them,
remove valve guide From cylinder head using
drift (Part No.2868 5890 06 05).
2.
Check the condition of valve guide oil seals.
3.
Check valve guide bore diameter in cylinder
head and if necessary, ream valve guide bore
in cylinder head to next over size.
4.
Install matching size valve guide in cylinder
head using drift (Part No. 2868 5890 06 05) and
spacer.
5.
Fit Valve guide oil seals
D. Valve Seat
1.
Check valve seat height with respect to cylinder
head mating surface. Replace valve seat inserts
if they are worn out beyond specified limit.
2.
Cut exhaust and inlet valve seats with a general
45
o
cutter.
NOTE
Valve seat must be absolutely faultless and without
any chatter marks
3.
If necessary lap the valve seats to a smooth and
even finish by using suitable hand pump grinder
or a lapping paste and valve itself.
4.
Smear valve seat with carbon blue. Install valve
in guide and turn it slowly under axial pressure.
5.
Contact line on valve seat must be around
entire circumference at equal width.
6.
Distance between narrow diameters of valve
face to contact line should be minimum 0.5 mm.
7.
Check for leakages through valve seat by
pouring fuel on valve head. Fuel must not seep
past valve seat.
E. Valve Seat Insert
1.
For removing valve seat inserts from cylinder
head use suitable boring machine. Bore old
insert 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
surface with crank case, place any soft
protective sheet metal under supports of puller.
3.
Measure valve seat insert bore diameter in
cylinder head.
4.
If boring and prying is done carefully without
damaging valve seat insert bore in cylinder
head, fitment of an oversize 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
maintained to ensure proper interference of
valve seat insert in its bore.
7.
Clean valve seat insert and its bore in cylinder
head thoroughly.