TIMING SPECIFICATIONS: Engine timing is directly related to the compression of the engine. The higher the compression, the less advance (as in advance of the piston’s arrival at top dead center or highest position) can be used for the timing position. To get more bottom end, advance the timing from the recommended range. Since the exhaust pipe, carburetor, cylinder porting, and cylinder head design are all tied to the amount of heat that an engine makes, they must be taken into consideration when setting the engine’s timing. It’s all about heat that is generated in the engine’s combustion chamber. An engine burning a specific fuel can only tolerate a certain amount of heat, and all of the above mentioned factors are related to this heat. Since the ignition timing and its effect on that heat are directly related to the engine’s longevity, it is critical that you get it right. Too much and you toast the engine, too little and you are giving up horsepower. Gasoline and alcohol (methanol) have different figures due to their burn characteristics. Generally, alcohol burns slower than gasoline and needs more heat. This can be accomplished in one of two ways - advance the timing or up the compression. You still can only have so much heat for the engine to operate. The following timing specifications are offered only as a starting point guideline!
Timing the PVL ignition to your engine requires the use of a dial indicator type timing gauge to measure the position of the piston. By aligning the marks on both the rotor and the stator, and measuring the position of the piston before top dead center (BTDC), you will be able to set the timing to the needs of your engine. The timed interval between ignition and when the piston reaches TDC in a cylinder is expressed in degrees of flywheel (crankshaft) rotation. Because the spark is always fired before the piston reaches TDC, the timing is considered “advanced”. The greater the number of degrees before TDC the spark is fired, the more advanced the ignition timing is for that cylinder. When the number of degrees at which the spark is fired is reduced, the timing has been “retarded”.
It should be noted that even though the timing in a cylinder may have been retarded, the spark is still being fired before TDC and is still considered advanced, just not as much.
Izvor:
http://www.pentonrac...nstructions.pdf
http://www.pentonrac...ignitions.shtml
Ovo sam nesto nakopao na netu. Koliko sam ja razumeo sve ovo, ja sam proslu radilicu spucao samo zato sto sam paljenje oterao u 40*+ pre GMT. Secam se da nisam mogao da nateram motor preko 12k obrtaja, pa sam umesto da trazim problem u karburatoru ili prenosu, ja pametan rotirao stator do kraja u levo bez provere paljenja stroboskopom... Time sam dobio obrtaje 14k+ ali sam u delu u kome kriva ide u najveci advance (od 2000 do 6000rpm) imao toliko preuranjeno paljenje (jbg skoro 45*) da je nesto moralo da se desi. Ok, motor je preletao te obrtaje ali uz onaj grizgavi zvuk. Zamisljam ovu krivu paljenja pomerenu za 10-15* na gore.
Koje mogu da budu posledice prevelikog predpaljenja?
Mario, on 27 May 2015 - 10:56, said:
moraš sad malo da lažiraš te uglove, da umiriš potrošnju... vozio sam i ja T6 na Selettri pa sam varao da mi klip ne dobije po nosu
Verovatno si na to dobijanje po nosu mislio? A ono pomeranje krive na ranije, mislis da je spustim blize GMT (da retardiram paljenje odnosno pomerim stator u desno?