NANO AMT

108

ENGINE 273 MPFI

VALVE

Valve Dimensions:

NO VALVE DIMENSIONS INLET

EXHAUST

1. Valve head dia ‘A’ mm ø32.5 ± 0.2 ø29.5 ± 0.2

2. Valve seat angle

45° +15’

3. Valve stem dia ‘B’ mm ø5.968

ø5.936

± 0.007

4. Valve seat dia ‘C’ mm ø30.11

ø26.0

5. Valve seat end

1.2

1.25

distance from valve

face ‘D’ mm

6. Maximum run out of

0.03

valve seat with respect

to valve stem in mm

Valve Repair :

•

Check valve leakages by pouring gasoline on

valve head. Gasoline must not seep past valve

seat.

•

Valves with burnt heads, excessive scoring and

wear on stem should be replaced.

•

Check valve seat run out with respect to valve

stem. If it exceeds specified limit (0.03 mm)

replace valve. No attempt should be made to

straighten bent valves. If valve is free from any

other defects except worn out seat, then only it

can be rematched on valve grinding

machine as follows :

i. Clamp valve on grindingmachine jaws as close

as possible to valve head.

ii. Adjust grinding angle on graduated scale to

achieve correct valve seat angle.

iii. Feed valve slowly towards grinding wheel until

wheel just touches valve head.

iv. Grind at low feed until valve seat is just clean

all around.

Valve Lapping:

Lap the valve on the seat in two steps, first with a

coarse size lapping compound applied to the face and

the second with a fine-size compound, each time

using a valve lapper according to the usual lapping

method.