Question

SI Engines - What are the main emissions? What are
engine manufacturers doing do reduce engine emissions?

Answer 1

si engines spark ignitor to ignite the compresed petrol....in this case fuel is compresd,ingitd n the presure creatd by burng causes the engine to wrk...

Answer 2

first of all in si engine petrol is not burnt by by pressure it is burnt by spark caused by spark plug.
emissions include compounds of SOx COx .
proper timing for spark , timing for valve opening and closing,piston and engine design, as well as engine cooling, etc are the item taken in consideration for reduction of emmision

Answer 3

Good answer @akashay045 and I might add that the petrol is not compressed either. Well not in the conventional sense. It is injected into the chamber in a somewhat aerosol form that is mixed with air and it is the air mixture that is compressed not the petrol. Sorry to pick apart your answer @pkjha3105. Nothing against you, just trying to improve the over-all response to the asker. Your input is appreciated. :)