2.10.3. Operational development of a saddle of the valve in a head of the block of cylinders and operational development of valves

Saddles of valves with wear tracks and an obgoraniye can be led up until the most admissible amount of operational development is maintained.

If the amount of operational development is exceeded, then the hydraulic compensator of valvate gaps will not work any more. In this case it is necessary to replace a head of the block of cylinders.

To lead up saddles of valves until the perfect spot of contact is received. Rings of saddles of valves can be replaced by means of the ordinary factory tool. Development are necessary for operational development. As the handling of this tool demands certain skills, works need to be performed industrially.

Prevention

Rings of saddles of final valves have additional narrowing. At operational development it is strict to pay attention to that the radius of narrowing was kept.

Calculation of the most admissible amount of operational development

PERFORMANCE ORDER
1. To insert the valve and to densely press it to a saddle.
2. To measure distance (a) between the end of a core of the valve and the upper edge of a head of the block of cylinders.
3. To receive the most admissible amount of operational development (b), it is necessary to subtract the minimum size (see table 1) the measured distance (and).

Table 1

Engine type
Minimum size, mm
Inlet valve
Final valve
Petrol engine
33,80
34,10
Diesel engine
35,80
36,10

Saddle of the inlet valve of the petrol engine
a. Minimum size
b. The most admissible amount of operational development (is calculated)		 z. Bottom edge of a head of the block of cylinders
30 °. Top angle of adjustment
45 °. Valve saddle corner

Saddle of the final valve of the petrol engine

a. Minimum size
b. The most admissible amount of operational development (is calculated)		 z. Bottom edge of a head of the block of cylinders
30 °. Top angle of adjustment
45 °. Valve saddle corner

Angle of processing and diameter of a saddle of the valve

Petrol engine
Inlet valve, mm
Final valve, mm
and
37,2
32,4
with
about 2,0
about 2,4

Angle of processing and diameter of a saddle of the valve

Diesel engine
Inlet valve, mm
Final valve, mm
and
max 37,2 *
min 33,2 *
in
34,8
30,4
with
2,7
2,05

* outer diameter of an adjustment mill

Valve sizes

Valve sizes

Engine
Inlet valve, mm
Final valve, mm
Petrol engine
and = 40,00
and = 33,00
b = 7,97
b = 7,95
with = 91,00
c = 90,80
= 45 °
= 45 °
Diesel engine
a = 36,00
a = 31,00
b = 7,97
b = 7,95
with = 95,00
c = 95,00
= 45 °
= 45 °
Prevention

The valve cannot be led up, only grinding in is allowed.

Size of a head of the block of cylinders

Petrol engine: and = 132,6 mm
Prevention

The head of the block of cylinders of the diesel engine cannot be led up.