Mercedes S-class W202
1993-2000 of release
Repair and car operation
+ 1.2. The general data
+ 2. Maintenance service
+ 3. Engines
+ 4. Greasing system
+ 5. Cooling system
+ 6. Heating, ventilation
- 7. Ignition system
7.2. Safety precautions at repair of electronic system of ignition
7.3. Ignition coils
- 7.4. Spark plugs
7.4.2. An index калильного numbers
+ 7.5. The device of a preliminary warming up of a diesel engine
+ 8. Fuel system
+ 9. Transmission
+ 10. A running gear
+ 11. A steering
+ 12. Brake system
+ 13. A body
+ 14. An 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 a gas mixture slips. Readiness for engine start, an operating mode depend on a spark plug at idling, acceleration (dispersal) and the maximum speed. Therefore does not follow without reason to refuse from the type of spark plugs ordered by factory which is defined, among other, an index калильного numbers.
The index калильного numbers specifies degree of thermal loading of a spark plug. The more low an index калильного numbers, the above thermal loading. Hence, the candle can take away is better heat thanks to what prevents harmful калильное ignition (an engine detonation). However, the candle with high thermal loading has that lack that its temperature of self-cleaning also above. Therefore it becomes covered by a soot, in particular faster in the event that the engine during driving does not reach the working temperature (movement in a city, driving on short distances in the winter). As a rule, "cold" spark plugs (an index калильного numbers since 06) are applied in "hot" engines from which power units high capacity is required.
At application of copper cores (Cu) in the central electrodes of candles and the more so at use of silver central electrodes heat conductivity and, thereby, thermal loading raises.
The index калильного numbers contains in a code of a spark plug which is deciphered as follows:
Firm Bosch spark plugs
(1) W = a carving of M 14 х 1,25 with flat dense landing, SW 21 (the size on a turn-key basis); F = a carving of M 14 х 1,25 with flat dense landing, SW 16 (the size on a turn-key basis); Н = a carving of M 16 х 1,25 with conic dense landing, SW 16 (the size on a turn-key basis).
(2) R = with the resistor for suppression of hindrances. Thanks to it, functioning of system of ignition does not render a radio noise.
(3) Kalilnyj an index. The scale калильных numbers includes numbers from 06 – "cold" to 13 – "warm". Thus the index 8 corresponds old калильному to number 175 (earlier marks), 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 concern spark plugs with flat dense landing. Letter addition "Т" (for example, "ДТ") = 3 lateral electrodes.
(5) Material of the central electrode: without instructions = Cu-Ni – an alloy, With = Ni-Cu – the combined central electrode, S = a silver central electrode, Р = a platinum central electrode.
(6) About = a standard spark plug with the strengthened central electrode.
Firm Beru spark plugs
(1) Diameter of a carving in mm, here: M 14 х 1,25.
(2) F = flat dense landing, To = conic dense landing, R = помехоподавляющий the resistor 5 clod / 10 clod.
(3) Index калильного numbers, decoding, as well as at firm Bosch.
(4) Lengths of the cut part, decoding, as well as at firm Bosch.
(5) Material of the central electrode: U = "ультра" (Ni-Cu – the combined central electrode), S = a silver central electrode, Р = a platinum central electrode.
(6) About = the strengthened central electrode; R = with the protective resistor (for reduction обгорания electrodes of spark plugs).
Kalilnye numbers of spark plugs for the engines applied on the S-class
The distance between electrodes in spark plugs makes 0,8 mm.