Contents: Valve seat dimensions ↳ Cylinder head gasket ↳ Cylinder head gasket designation ↳ Combustion chambers ↳ Valve seats ↳ Valve springs ↳ Valves ↳
Dimensions of the swirl combustion chamber nest in the cylinder head
Valve seat dimensions
The cylinder head is cast from cast iron and has inserted valve seats and swirl combustion chambers. The camshaft bearing seats are made directly in the cylinder head material.
| Diameters of the holes of the camshaft bearing seats: | |
| – nominal: | 30,500 – 30,525 mm; |
| – repair: | 30.575 – 30.600 mm. |
| Tappet seat hole diameters: | |
| – nominal: | 35,000 – 35,030 mm; |
| – repair: | 35,500 – 35,530 mm. |
| Valve guide hole diameters: | |
| – nominal: | 8,000 – 8,035 mm; |
| – repair: | 8.263 – 8.288 mm. |
| Diameters of the swirl combustion chamber nests (see Fig. Dimensions of the swirl combustion chamber nest in the cylinder head): | |
| – nominal: | |
| size A: | 31,250 – 31,280 mm; |
| size B: | 27,530 – 27,560 mm; |
| – repair: | |
| size A: | 31,550 – 31,580 mm; |
| size B: | 27,830 – 27,960 mm. |
| Height of the swirl combustion chamber nests C (see Fig. Dimensions of the swirl combustion chamber nest in the cylinder head): | |
| – nominal: | 4.983 – 5.034 mm; |
| - repair: | 5.223 – 5.284 mm. |
Cylinder head gasket
The thickness of the cylinder head gasket is selected depending on the protrusion of the pistons above the upper plane of the cylinder block, taking into account the value of the most protruding piston.
The thickness of the gasket is identified by the corresponding designation:
- for cylinder blocks with nominal cylinder diameters: the gasket has cutouts;
- for cylinder blocks with cylinder repair diameters (0.5 or 1.0): the gasket has a hole.
Cylinder head gasket designation
Piston protrusion (mm) | Designation of the head gasket on the cylinder block with cylinder diameters | |
| nominal | repair | |
| 0,500 – 0,680 | 2 cutouts | 2 holes |
0,681 – 0,740 | 3 cutouts | 3 holes |
| 0,741– 0,840 | 4 cutouts | 4 holes |
Installation method: The cylinder head gasket is installed with the inscription "OBEN-TOP" facing the head (the inscription should be visible after the gasket is installed on the cylinder block).
Combustion chambers
Swirl combustion chambers, steel, inserted into the cylinder head and fixed with a steel ball.
Chamber type: vortex Ricardo Comet Mark V.
Protrusion of combustion chambers from the lower plane of the cylinder head: 0–0.061 mm.
Valve seats
The valve seats are pressed into the cylinder head.
Valve seat dimensions
| Size (mm) as per Fig. Valve seat dimensions | Valve seat | |
intake | graduation | |
| Nominal diameter: | ||
A | 38,00 – 38,03 | 33, 00 – 33,03 |
IN | 8,3 – 8,5 | 8,8 – 9,0 |
| 1. repair diameter: | ||
A | 38,20 – 38,03 | 33,20 – 33,23 |
IN | 8,6 – 8,8 | 9,1 – 9,3 |
| 2. repair diameter: | ||
A | 38,40 – 38, 43 | 33,40 – 33,43 |
IN | 8,9 – 9,1 | 9,4 – 9,6 |
Valve springs
The springs are the same for both intake and exhaust valves. Free length: 43 mm.
Valves
The valves installed in the cylinder head are actuated by camshaft cams through cylindrical tappets.
Valve sizes
| Size type | Valve | |
| inlet | outlet | |
| Rod diameter: | ||
| - nominal | 7,82 – 7,97 | 7,81 – 7,96 |
| - 1. repair | 8,02 – 8,17 | 8,01 – 8,16 |
| - 2. repair | 8,22 – 8,37 | 8,21 – 8,36 |
| Plate diameter | 36,40 – 36,60 | 31,90 – 32,10 |
| Valve length | 107,05 – 107,15 | 109,15 – 109,25 |
Valve clearance (cold)
Intake valve clearance: 0.35±0.05 mm.
Exhaust valve clearance: 0.50±0.05 mm.
Adjusting the valve clearance: by selecting the thickness of the adjusting plates located in the recess of the tappets.
Adjustment plate thickness range: 3.00–4.75 mm.
The difference in thickness of the adjustment plates: 0.05 mm.
Pushers
Outer diameter:
- nominal: 34.950–34.975 mm;
- repair: 35.450–35.475 mm.