Ford Sierra

3.2.1.2.2. A head of the block of cylinders

THE GENERAL DATA

The sizes of a nest of the vortical chamber of combustion in a head of the block of cylinders


The sizes of a saddle of the valve

The head of the block of cylinders is cast from pig-iron and has inserted saddles of valves and vortical chambers of combustion. Nests of bearings of a cam-shaft are executed directly in a material of a head of the block of cylinders.

Diameters of apertures of nests of bearings of a cam-shaft:
– The nominal:	30,500 – 30,525 mm;
– The repair:	30,575 – 30,600 mm.
Diameters of apertures of nests of pushers:
– The nominal:	35,000 – 35,030 mm;
– The repair:	35,500 – 35,530 mm.
Diameters of apertures of directing valves:
– The nominal:	8,000 – 8,035 mm;
– The repair:	8,263 – 8,288 mm.
Diameters of nests of vortical chambers of combustion (fig. the Sizes of a nest of the vortical chamber of combustion in a head of the block of cylinders see):
– The nominal:
• the size And:	31,250 – 31,280 mm;
• the size In:	27,530 – 27,560 mm;
– The repair:
• the size And:	31,550 – 31,580 mm;
• the size In:	27,830 – 27,960 mm.
Height of nests of vortical chambers of combustion With (fig. the Sizes of a nest of the vortical chamber of combustion in a head of the block of cylinders see):
– The nominal:	4,983 – 5,034 mm;
– The repair:	5,223 – 5,284 mm.

Lining of a head of the block of cylinders

The thickness of a lining of a head of the block of cylinders steals up depending on выступания pistons over the top plane of the block of cylinders, and value of the most acting piston is taken into consideration.

The thickness of a lining is identified on corresponding designation:

 – For blocks of cylinders with nominal diameters of cylinders: the lining has cuts;
 – For blocks of cylinders with repair diameters of cylinders (0,5 or 1,0): the lining has an aperture.

Designation of linings of a head of the block of cylinders

Выступание the piston (mm)	Designation of a lining of a head on the block of cylinders with diameters of cylinders
	The nominal	The repair
0,500 – 0,680	2 cuts	2 apertures
0,681 – 0,740	3 cuts	3 apertures
0,741 0,840	4 cuts	4 apertures

Installation method: the lining of a head of the block of cylinders is established by an inscription "OBEN-TOP" in a head direction (the inscription should be visible after the lining is established on the block of cylinders).

Combustion chambers

Vortical chambers of combustion, steel, inserted into a head of the block of cylinders and fixed by means of a steel ball.

Chamber type: vortical Ricardo Comet Mark V.
Выступание chambers of combustion from the bottom plane of a head of the block of cylinders: 0–0,061 mm.

Saddles of valves

Saddles of valves впрессованы in a head of the block of cylinders.

The sizes of saddles of valves

The size (mm) according to fig. the Sizes of a saddle of the valve	Valve saddle
	The inlet	The final
Nominal diameter:
AND	38,00 – 38,03	33, 00 – 33,03
IN	8,3 – 8,5	8,8 – 9,0
1. Repair diameter:
AND	38,20 – 38,03	33,20 – 33,23
IN	8,6 – 8,8	9,1 – 9,3
2. Repair diameter:
AND	38,40 – 38, 43	33,40 – 33,43
IN	8,9 – 9,1	9,4 – 9,6

Springs of valves

Springs identical both for inlet, and for final valves. Free length: 43 mm.

Valves

Established in a head of the block of cylinders of the valve are put in action by cam-shaft cams through cylindrical pushers.

The sizes of valves

Kind of the size	The valve
	The inlet	The final
Diameter of a rod:
– The nominal	7,82 – 7,97	7,81 – 7,96
– 1. The repair	8,02 – 8,17	8,01 – 8,16
– 2. The repair	8,22 – 8,37	8,21 – 8,36
Diameter of a plate	36,40 – 36,60	31,90 – 32,10
Length of the valve	107,05 – 107,15	109,15 – 109,25

Working backlash of valves (in a cold condition)

Backlash of inlet valves: 0,35 ± 0,05 mm.

Backlash of final valves: 0,50 ± 0,05 mm.

Adjustment of a backlash of valves: selection of a thickness of the adjusting plates located in deepening of pushers.

Range of adjusting plates on a thickness: 3,00–4,75 mm.

Difference on a thickness of adjusting plates: 0,05 mm.

Pushers

External diameter:

 – The nominal: 34,950–34,975 mm;
 – The repair: 35,450–35,475 mm.