Why is the spark ignited just before TDC and not at TDC?
Why is the spark ignited just before TDC and not at TDC?
Just before top dead center (TDC) the spark plug fires to start combustion. With a rich air/fuel mixture this starts burning very rapidly and the peak firing pressure will be higher than normal and also closer to TDC. The very rapid rate of pressure rise of the uncontrolled burning mixture causes detonation.
Will Bad timing chain cause no spark?
If the timing belt slipped several teeth then the camshaft AND distributor rotor may both be retarded. If the rotor was too retarded then the coil can create the spark… but if the rotor isn’t on a dizzy cap terminal then you won’t get spark routed to the plug wire.
When is the top dead center of an engine?
Top dead center is the point when the piston of the number one cylinder in an engine is at its highest point, and on the compression stroke of the engine’s four-stroke cycle.
How to find the dead center of a spark plug?
Method 1 of 2: Finding top dead center for engines with an easily accessible spark plug hole 1 A helping hand (for identifying the compression stroke) 2 Flashlight 3 Ratchet and socket set 4 Spark plug socket More …
When do you need to know top dead center ( TDC )?
Whenever you are doing a rebuild, building a new engine; or simply want to check and make sure the timing marks on your damper are still accurate. So, If you’re relatively new to engine work and have ever pulled, or need to pull, the distributor or damper from your engine; finding Top Dead Center (TDC) on piston #1 becomes an instant priority.
Where is the dead center mark on a crankshaft?
Continue to turn the crankshaft until the zero or top dead center mark on the pulley matches up with the pointer on the engine. For most engines, the zero or top dead center mark will be the first mark, or will be clearly marked in a different color or manner than the other marks on the pulley.
How do you find the dead center on an engine?
Usually it can be found by looking at timing marks; but on some engines these marks may be lost or hidden. Fortunately there’s an easy way to discover top dead center without the use of any timing marks. So, Being able to accurately find Top Dead Center (TDC) is a critical step; no matter what engine you are working with.
Whenever you are doing a rebuild, building a new engine; or simply want to check and make sure the timing marks on your damper are still accurate. So, If you’re relatively new to engine work and have ever pulled, or need to pull, the distributor or damper from your engine; finding Top Dead Center (TDC) on piston #1 becomes an instant priority.
Where to find the top dead center on a compression stroke?
As a general reference point, or when installing a distributor, Top Dead Center (TDC) on the compression stroke is required. Usually it can be found by looking at timing marks; but on some engines these marks may be lost or hidden.
