Let me explain it another way.

The argument I'm having is the following:

I am trying to explain to the other individual that the spark happens 16 degrees BEFORE the piston arrives at TDC on the compression upstroke. You can advance a little more to the point of detonation for a more complete and efficient burn whereas retarding will lose some power and efficiency.

But the other guy is yelling and screaming profanities at me with big bold text. He says that the spark happens 16 degrees AFTER the piston has been at top dead center to push the piston down for the power stroke. He says that my explanation would counteract the crankshaft rotation and destroy the motor.

Here is his exact explanation:

HOW THE FUCK CAN YOU SPARK BEFORE TDC?!!!!! YOU IDIOT. YOU WILL FORCE THE CRANK IN REVERSE. IF YOU HAVEN'T MADE IT TO TDC YET YOU CANNOT SPARK. YOU WILL TWIST YOUR CRANK INTO SCRAP METAL. THE SPARK HAS TO HAPPEN AFTER TDC SO THAT THE POWER STROKE IS GOING BACK DOWN. YOU CANNOT SPARK WHILE THE PISTON IS STILL COMING UP ON IT'S COMPRESSIONS STROKE YOU FUCKING ARMY RETARD!!!!! IF GEORGE W BUSH SAID YOUR CIVIC WAS GAY WOULD YOU BELIEVE HIM?

Who is correct here??????????