General information
The engine is four-stroke, four-cylinder, single-row. The engine is located in the front of the body across the axis of the car.
Main technical characteristics
Cylinder head for B3, B5, B6 engines
The cylinder head is cast from aluminum alloy. In the cylinder head of the B6 engine, multi-sphere combustion chambers are made, in the cylinder head of the B3 and B5 engines - wedge-shaped combustion chambers. Seats and valve guides are pressed into the cylinder head. The sockets for the camshaft bearings are integral with the cylinder head. The oil lines of the rocker axles are plug-in.
Head height along the parting planes, mm: 107.4-107.6.
Grinding tolerance, mm: 0.20.
Warping of the surface of the cylinder head, no more than, mm: 0.15.
Valves
The valves are located in the cylinder head in a V-shape and are actuated by the camshaft cams via rocker arms.
Valve specifications
Clearances in the valve drive mechanism
B6 engine
The normal gap between the ends of the rocker arm adjusting screw and the valve stem, measured with a feeler gauge on a hot engine, is 0.30 mm for intake and exhaust valves.
B3 to B5 engines
The clearances in the valve drive mechanism are adjusted automatically by hydraulic tappets.
Valve seats
The valve seats are pressed into the cylinder head.
Bevel angle: 45°.
Working chamfer width, mm: 1.1-1.7.
Guide bushings
Inner diameter, mm: 7.01-7.03.
Valve springs
Each intake and exhaust valve of the B3 and B5 engines is equipped with one spring, and the B6 engine with two.
Characteristics of intake and exhaust valve springs
Cylinder head for B6 EGI engine
The cylinder head has four valves per cylinder and is cast from aluminum alloy. It has wedge-shaped combustion chambers. Seats and valve guides are plug-in. In the upper part of the cylinder head there are five bearings for the camshaft journals. The supports are detachable. The upper half is in the bearing housings, and the lower half is pressed into the cylinder head. The bearing holes are machined complete with the bearing housings, so they are not interchangeable.
Head height along the parting planes, mm: 133.8-134.0.
Grinding tolerance, mm: 0.20.
Warping of the surface of the cylinder head, no more than, mm: 0.15.
Valves
The valves are located in the cylinder head in a V-shape and are actuated directly by the camshaft cams via hydraulic tappets.
Valve specifications
Clearances in the Valve Drive Mechanism
Valve clearances are compensated automatically by the oil pressure in the hydraulic tappets.
Valve seats
The valve seats are pressed into the cylinder head.
Working chamfer angle; 45°.
Working chamfer width, mm: 0.8-1.4.
Valve guides
Inner diameter, mm: 6.01-6.03.
Valve springs
Each inlet and outlet valve is equipped with one spring. Spring length, mm:
- free: 45.6;
- minimum allowable: 44.4.
Valve lifters
Gap between pushers and cylinder head, mm:
- nominal: 0.07-0.08;
- maximum allowable: 0.18.