CITROEN C5 Handbook page 54

Piston
Engine Thickness
stand-proud
plate
(mm)
0.55 to 0.60 1.25 ± 0.04
0.61 to 0.65 1.30 ± 0.04
4HX
0.66 to 0.70 1.35 ± 0.04
0.71 to 0.75 1.40 ± 0.04
Cylinder head gasket.
Multilayer cylinder head gasket.
Select seal thickness as a function of the piston stand-proud.
CYLINDER HEAD
Engine : 4HX
Cylinder head gasket identification
Number of notches
At A At B
(mm)
1
2
1
3
4
51
B1DP18XD