Service Data and Specifications (S.D.S.) - Inspection and Adjustment (Cylinder Head / Valve)

EM-259spec table

Valve length and margin differ between SR20DE and SR20DET.

Inspection and Adjustment

CYLINDER HEAD

Cylinder head (Unit: mm (in))

Item	Standard	Limit
Head surface distortion	Less than 0.03 (0.0012)	0.1 (0.004)

Head surface distortion

StandardLess than 0.03 (0.0012)

Limit0.1 (0.004)

Specification	Value
Nominal cylinder head height	H = 136.9 - 137.1 (5.390 - 5.398)mm (in)

Nominal cylinder head height

H = 136.9 - 137.1 (5.390 - 5.398)mm (in)

VALVE

Valve (Unit: mm (in))

Item	Value
Valve head diameter "D" - Intake	34.0 - 34.2 (1.339 - 1.346)
Valve head diameter "D" - Exhaust	30.0 - 30.2 (1.181 - 1.189)
Valve length "L" - Intake SR20DE	101.19 - 101.61 (3.9839 - 4.0004)
Valve length "L" - Intake SR20DET	101.845 - 102.355 (4.0096 - 4.0297)
Valve length "L" - Exhaust SR20DE	102.11 - 102.53 (4.0201 - 4.0366)
Valve length "L" - Exhaust SR20DET	102.765 - 103.275 (4.0459 - 4.0659)
Valve stem diameter "d" - Intake	5.965 - 5.980 (0.2348 - 0.2354)
Valve stem diameter "d" - Exhaust	6.945 - 6.960 (0.2734 - 0.2740)
Valve seat angle "α" - Intake	45°15' - 45°45'
Valve seat angle "α" - Exhaust	45°15' - 45°45'
Valve margin "T" - Intake SR20DE	1.1 (0.043)
Valve margin "T" - Intake SR20DET	1.3 (0.051)
Valve margin "T" - Exhaust SR20DE	1.3 (0.051)
Valve margin "T" - Exhaust SR20DET	1.5 (0.059)
Valve margin "T" limit	More than 0.5 (0.020)
Valve stem end surface grinding limit	Less than 0.2 (0.008)

Valve head diameter "D" - Intake

Value34.0 - 34.2 (1.339 - 1.346)

Valve head diameter "D" - Exhaust

Value30.0 - 30.2 (1.181 - 1.189)

Valve length "L" - Intake SR20DE

Value101.19 - 101.61 (3.9839 - 4.0004)

Valve length "L" - Intake SR20DET

Value101.845 - 102.355 (4.0096 - 4.0297)

Valve length "L" - Exhaust SR20DE

Value102.11 - 102.53 (4.0201 - 4.0366)

Valve length "L" - Exhaust SR20DET

Value102.765 - 103.275 (4.0459 - 4.0659)

Valve stem diameter "d" - Intake

Value5.965 - 5.980 (0.2348 - 0.2354)

Valve stem diameter "d" - Exhaust

Value6.945 - 6.960 (0.2734 - 0.2740)

Valve seat angle "α" - Intake

Value45°15' - 45°45'

Valve seat angle "α" - Exhaust

Value45°15' - 45°45'

Valve margin "T" - Intake SR20DE

Value1.1 (0.043)

Valve margin "T" - Intake SR20DET

Value1.3 (0.051)

Valve margin "T" - Exhaust SR20DE

Value1.3 (0.051)

Valve margin "T" - Exhaust SR20DET

Value1.5 (0.059)

Valve margin "T" limit

ValueMore than 0.5 (0.020)

Valve stem end surface grinding limit

ValueLess than 0.2 (0.008)

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