Nanni N4.40 - Cylinder Head Flaw; Cylinder Head Surface Flatness

ENGINE
03-M-E3B, 03-M-DI-E3B, 03-M-E3BG, WSM
1-S75
Cylinder Head Surface Flatness
1. Clean the cylinder head surface.
2. Put a straightedge on the cylinder head.
3. Measure the clearance with a feeler gauge at the 6 places (see
the figure).
4. If the measurement is more than the allowable limit, make it
straight with a surface grinder.
IMPORTANT
• Do not put a straightedge on the combustion chamber.
• Examine the valve recessing after you correct.
M00000003ENS0106US1
Cylinder Head Flaw
1. Prepare an air spray red check.
2. Clean the surface of the cylinder head with detergent (2).
3. Apply some red permeative liquid (1) on the cylinder head
surface. After you apply, do not touch it for 5 to 10 minutes.
4. Clean away the red permeative liquid on the cylinder head
surface with detergent (2).
5. Apply the white developer (3) on the cylinder head surface.
6. If you found a red flaw, replace the cylinder head.
M00000003ENS0107US1
Cylinder head surface
flatness
Allowable limit
0.05 mm
0.002 in.
(1) Red Permeative Liquid
(2) Detergent
(3) White Developer
KiSC issued 06, 2009 A