S-class W202 Mercedes
1993-2000 of release
Repair and car operation
+ 1.2. General information
+ 2. Maintenance
+ 3. Engines
+ 4. Greasing system
+ 5. Cooling system
+ 6. Heating, ventilation
- 7. Ignition system
7.2. Safety measures at repair of electronic system of ignition
7.3. Ignition coils
- 7.4. Spark plugs
7.4.2. Index of kalilny number
+ 7.5. Device of a preliminary warming up of a diesel engine
+ 8. Fuel system
+ 9. Transmission
+ 10. Running gear
+ 11. Steering
+ 12. Brake system
+ 13. Body
+ 14. Electric equipment
+ 14.2. Electroschemes
The spark plug consists of the central electrode, an insulator with the case and a lateral electrode. The lateral electrode is tightly fixed in an insulator, the insulator is strongly connected with the case. Between the central and lateral electrode the igniting spark which sets fire to gas mixture slips. Readiness for engine start, an operating mode depend on a spark plug when idling, acceleration (dispersal) and the maximum speed. Therefore does not follow without the reason to refuse from ordered by plant such as spark plugs which is defined, among other things, by an index of kalilny number.
The index of kalilny number specifies degree of thermal loading of a spark plug. The index of kalilny number is lower, the thermal loading is higher. Therefore, the candle can take away better heat thanks to what prevents harmful kalilny ignition (an engine detonation). However, the candle with high thermal loading has that shortcoming that its temperature of self-cleaning is also higher. Therefore it becomes covered by a soot, in particular quicker in case the engine during driving does not reach the working temperature (movement in the city, driving on short distances in the winter). As a rule, "cold" spark plugs (an index of kalilny number since 06) are applied in "hot" engines from which power units the high capacity is required.
At use of copper cores (Cu) in the central electrodes of candles and the more so when using silver central electrodes heat conductivity and, thereby, thermal loading raises.
The index of kalilny number contains in a code of a spark plug which is deciphered as follows:
Bosch firm spark plugs
(1) W= a carving of M 14 x 1,25 with flat dense landing, SW 21 (the turnkey size); F= a carving of M 14 x 1,25 with flat dense landing, SW 16 (the turnkey size); N = a carving of M 16 x 1,25 with conic dense landing, SW 16 (the turnkey size).
(2) R= with the resistor for suppression of hindrances. Thanks to it, functioning of system of ignition does not render a radio noise.
(3) Kalilny index. The scale of kalilny numbers includes numbers from 06 – "cold" to 13 – "warm". Thus the index 8 corresponds to old kalilny number 175 (earlier marking), 7-200, 6-225 etc.
(4) In = length of the cut part of 19 mm, a normal trajectory of the spark category; Д= length of the cut part of 19 mm, the stretched trajectory of the spark category; L= length of the cut part of 19 mm, extremely stretched trajectory of the spark category. Data on length of the cut part belong to spark plugs with flat dense landing. Letter "T" addition (for example, "DT") = 3 lateral electrodes.
(5) Material of the central electrode: without the instruction = Cu-Ni – an alloy, With = Ni-Cu – the combined central electrode, S = a silver central electrode, R = a platinum central electrode.
(6) About = a standard spark plug with the strengthened central electrode.
Beru firm spark plugs
(1) Diameter of a carving in mm, here: M 14 x 1,25.
(2) F= flat dense landing, To = conic dense landing, R = the pomekhopodavlyayushchy resistor of 5 kiloohms / 10 kiloohms.
(3) An index of kalilny number, interpretation, as well as at Bosch firm.
(4) Length of the cut part, interpretation, as well as at Bosch firm.
(5) Material of the central electrode: U= "ultra" (Ni-Cu – the combined central electrode), S = a silver central electrode, R = a platinum central electrode.
(6) About = the strengthened central electrode; R= with the protective resistor (for reduction of an obgoraniye of electrodes of spark plugs).
Kalilnye of number of spark plugs for the engines applied on the S-class
The distance between electrodes in spark plugs makes 0,8 mm.