Contents: Cylinder block ↓ Crankshaft ↓ Cylinder head ↓ Carburetor ↓ Exhaust system ↓ Ignition system ↓
This car is equipped with a model 21081 engine with a reduced piston stroke (60.6 mm).
Cylinder block
Compared to the 2108 engine, the height of the cylinder block is reduced by 5.6 mm and is 242-242.2 mm. There are no special features in repairing the cylinder block.
Crankshaft
Due to the reduced piston stroke, the distance between the axes of the connecting rod and main journals has been reduced by 5.2 mm. The crankshafts of the 21081 engines can be distinguished by their overall dimensions and by the location of the lubrication holes on the connecting rod journals. In the 21081 crankshafts, they are offset by 3.7 mm from the journal axis in the direction of the main journals, and in the 2108 crankshafts, by 1.5 mm in the opposite direction from the axis (figure 185).
Figure 185. Location of lubrication holes on the connecting rod journals of the crankshaft of engines 2108 (a) and 21081 (b)
When grinding the connecting rod journals, the distance between the axes of the connecting rod and main journals must be maintained such that the piston stroke is 60.6+0,05-0,10 mm.
Cylinder head
The cylinder head of the 21081 and 2108 engines differs only in the installation location of the tension roller stud. On 2108 engines, the stud is screwed into the lower hole 1 (figure 186), and on 21081 engines—into the upper opening 2.
(The original is on the portal www.VazBook.ru)
Figure 186. Location of tension roller studs on cylinder heads
Camshaft. Has a different profile and angular arrangement of cams, since the 21081 engine has different valve timing. To distinguish the camshaft of 21081 engines, a cylindrical belt 5 mm wide and 30 mm in diameter is cast on the right side of the third cam.
Carburetor
The carburetor 21081-1107010 is installed, which differs in calibration data (Table 33).
The methods of its disassembly, assembly and adjustment are the same as for the 2108-1107010 carburetor.
* The nominal fuel jet consumption is determined by reference jets using a special method. Not subject to control during operation.
Note: The marking of the jets is determined by the flow rate, which is measured using micrometers. The micrometers are adjusted using reference jets.
Exhaust system
An exhaust manifold with one outlet for exhaust gases and a single-pipe muffler inlet pipe have been installed. The clamp and bracket for fastening the inlet pipe to the cylinder block have also been changed.
Ignition system
A type 40.3706-10 ignition distributor sensor is installed with different characteristics of the centrifugal and vacuum ignition advance regulators (figure 187 and 188). To distinguish these ignition distributor sensors, a red mark is placed on the cover of the vacuum regulator.
Figure 187. Characteristics of the centrifugal regulator of the ignition distributor sensor type 40.3706-10:
A - ignition timing angle;
n — rotation frequency of the ignition distributor shaft
Figure 188. Characteristics of the vacuum regulator of the ignition distributor sensor type 40.3706-10:
A - ignition timing angle;
R - vacuum
The initial ignition advance angle of 21081 engines is 6°±1°.