How do you know if cylinder 1 is TDC?
Once the top dead center timing mark is lined up with the marker on the engine, the motor should now be at top dead center. To verify, shine the flashlight down into the spark plug hole. You should be able to see the top of the piston clearly near the top of the cylinder.
What does the 1 on distributor cap mean?
Now notice on the TOP (not the side) of the distributor cap the is a “1” raised letter. That indicates the tower where No 1 spark plug wire goes. Knowing the firing order, you can now plug in all your wires.
What valves should be open at TDC?
If a piston is at top dead center on the compression stroke, both the intake and exhaust valves should be closed. When at top dead center on the exhaust stroke, the exhaust valve should be open.
When is the rotor button supposed to be Poin?
The rotor button should be pointing to the number 1 position on the distributor cap when the number 1 piston is at top dead center (on the compression stroke). The pistons come up two times during the combustion cycle.
How to calculate the timing of a TDC rotor positon?
When #1 intake valve opens and then closes, start watching through the spark plug hole. (a wooden dowel rod is helpful here) watch the piston/dowell until it is at the very TOP of its travel. STOP. Now look at the timing pointer and TDC mark on the dampner/pulley. IT SHOULD LINE UP PERFECTLY.
Where are the timing marks on the gears?
When viewing the gears from the front, the timing mark on each timing gear should be at approximately the 10 o’clock position. To precisely verify TDC, use any suitable straight edge through the center holes of the gears and the timing marks (see dotted line in fig. 1). This properly indexes the camshaft/crankshaft to #1 TDC firing position.
When is the piston at the top of its stroke?
Simply put, Top Dead Center (TDC) is the position of an engine’s piston; when it is at the very top of its stroke. Depending on weather you need to be on the compression stroke or not; there are many methods that you can use: