This refers to when the spark plug fires on number one cylinder. All cylinders will fire at the same point in the stroke, but number one is used to set the timing. There is a notch or line on the crankshaft pulley that marks when the number one piston is at the top of the stroke. The timing is set before TDC so that the fuel can ignite before the piston reaches the top of the cylinder. This gets the most out of the explosion of the fuel. Timing is different for each make of engine, but usually 6-8 degrees before TDC.
TDC is 0 degrees TDC, not 10 degrees BTDC which is before top dead center. ATDC is after top dead center. Both of these in relation to piston height are "below top dead center".
TDC would be "Top Dead Center". BTDC would be "Before Top Dead Center".
bring number 1 cyldenr to top dead center before installing gears bring number 1 cyldenr to top dead center before installing gears bring number 1 cyldenr to top dead center before installing gears
Before top dead center
looking at the timing marks from the top left to right you have 5 degrees after top dead center, then top dead center then 5 degres 10, 15 then 20 befor top dead center. the timing is 7 degrees before top dead center
It is look like ruler with 0, 10, 20 number XXXXXXXXXXXXXXXXXXXXXXXXXXXXX The timing scale will have an "A" at the top and a "B" on the bottom. In the center is a "0". The "A" is for after top dead center. The "B" is for before top dead center. Each mark on the scale is 2 degrees. Timing is always set on before top dead center.
The piston will usually be a few degrees before top center.
93-98 240sx timing is 18-22 before top dead center
top dead center is what it stands for. top dead center
16 degrees before top dead center
what engine do you have in your impala?
The top dead cente