CYLINDER HEAD — Installation (Chart A — piston projection vs gasket)
EM-231spec tableUnverifiedCD engine (CD20). Chart A gasket grade table plus worked 4-cylinder, 4-measuring-point example. The footnote *1 reference to '0.553 (7) 5' has an unclear circled digit. Section tab marked 'CD'.
Relation between piston average projection and cylinder head gasket (Chart A)
Chart A — Relation between piston average projection and cylinder head gasket (Unit: mm (in))
A
Average value of piston projections mm (in)Less than 0.505 (0.0199)
Gasket thickness mm (in)1.15 +0.05/-0.05 (0.0453 +0.0020/-0.0020)
Number of notches1
B
Average value of piston projections mm (in)0.505 - 0.555 (0.0199 - 0.0219)
Gasket thickness mm (in)1.20 +0.05/-0.05 (0.0472 +0.0020/-0.0020)
Number of notches2
C
Average value of piston projections mm (in)Over 0.555 (0.0219)
Gasket thickness mm (in)1.25 +0.05/-0.05 (0.0492 +0.0020/-0.0020)
Number of notches3
Step 6
- 6Check if the average value of each projection obtained from step 2 is larger than the max. value of the standard projection (of selected gasket) incremented by 0.05 mm (0.0020 in). If so, use gasket that is 1 grade thicker. If not so, use gasket as selected in step 4.
SEM530D
Example
Gasket selection worked example (Unit: mm (in))
1.
ItemMeasured value (M1 / M2 / M3 / M4)
Cylinder No. 1M1: 0.53 (0.0209) / M2: 0.56 (0.0220) / M3: 0.53 (0.0209) / M4: 0.56 (0.0220)
Cylinder No. 2M1: 0.59 (0.0252) / M2: 0.55 (0.0217) / M3: 0.59 (0.0232) / M4: 0.55 (0.0217)
Cylinder No. 3M1: 0.53 (0.0209) / M2: 0.58 (0.0228) / M3: 0.57 (0.0224) / M4: 0.54 (0.0213)
Cylinder No. 4M1: 0.58 (0.0228) / M2: 0.51 (0.0201) / M3: 0.52 (0.0205) / M4: 0.57 (0.0224)
2.
ItemAverage value of each piston
Cylinder No. 10.545 (0.0215)
Cylinder No. 20.57 (0.0224)
Cylinder No. 30.555 (0.0219)
Cylinder No. 40.545 (0.0215)
3.
ItemAverage value of all pistons
Cylinder No. 10.55375 (0.02180)
Cylinder No. 2
Cylinder No. 3
Cylinder No. 4
4.
ItemRound off value
Cylinder No. 10.554 (0.0216) *1
Cylinder No. 2
Cylinder No. 3
Cylinder No. 4
5.
ItemDetermined gasket thickness (Temporarily)
Cylinder No. 11.20 (0.0472) (Grade B)
Cylinder No. 2
Cylinder No. 3
Cylinder No. 4
6.
ItemX: Maximum value of standard projection of selected gasket ... 0.555 (0.0219) (in chart A) + 0.05 (0.0020) = 0.605 (0.0238); Y: Maximum value in step 2 = 0.57 (0.0224); The relationship between X and Y is "X > Y". *2
Cylinder No. 1
Cylinder No. 2
Cylinder No. 3
Cylinder No. 4
7.
ItemDetermined gasket thickness (Finally)
Cylinder No. 11.20 (0.0472) (Grade B) *2
Cylinder No. 2
Cylinder No. 3
Cylinder No. 4
NOTE
*1: If the average value of projections for all pistons is, for example, 0.553 (?) 5, as shown in the table above, it should be rounded off as follows: If the digit in the forth decimal place (which is enclosed by a circle in this case) is smaller than 5, the average value should be regarded as 0.553 mm (0.0218 in); if it is larger than 5, the average value should be regarded as 0.554 mm (0.0218 in).
*2: If X < Y, then the thicker grade C gasket must be used.
See also
chart A