Not if all you are doing is replacing the rotor and/or distributor cap. If you are trying to find the correct way to wire the spark plugs then yes it is very important.
Typically it is the one that points toward the number one cylinder. Technically it can be any of them as long as the wires are in the correct firing order. When cylinder number one is a tdc, the rotor should be pointing at the number one cylinder. Thus the number one plug wire.
differential expansion is refer to differential distance between rotor blade and fix blade.rotor expand toward generator and casing expand toward control valve.when temperature increase ,expansion in casing and rotor.so rotor mass is less than casing which rotor expand more than casing.
Number one cylinder is located driver's side front of engine. With the # 1 piston at TDC on the compression stroke, the rotor will be pointing at #1 plug on cap.Number one cylinder is located driver's side front of engine. With the # 1 piston at TDC on the compression stroke, the rotor will be pointing at #1 plug on cap.
As on any automobile engine, the rotor turns in a 360 degree circle. When the piston for the number one cylinder is at top dead center on the compression stroke the rotor should point to the number one spark plug tower of the distributor cap.
Number 1 cylinder, which would be the first cylinder on the drivers side of the engine. You want the rotor pointing towards the 5 O'Clock position looking at the distributor from the front.
Follow wire from # 1 cylinder to cap. check position of rotor. see link
It's called a taper. Time to replace the rotors, calipers and brake pads.
If you will remove the #1 plug, (driver's side front of engine), then turn that cylinder to top dead center, (TDC), on the compression stroke, you can then remove the distributor cap and look at the rotor. The rotor will now be pointing to the #1 plug position. GET THE NUMBER ONE CYLINDER TOP DEAD AND THE ROTOR IN THE DISTRIBUTOR SHOULD BE PIONTING AT IT
With the distributor cap removed, the rotor should be pointing towards the terminal that corresponds to the number one cylinder in the engine's firing order. This position is critical for proper ignition timing, as it indicates where the spark will be sent when the engine is cranked. If the rotor is misaligned, it can lead to misfires or starting issues. Always ensure the engine is at top dead center (TDC) on the compression stroke for the number one cylinder when setting the rotor position.
You must remove the distributor and rotate it back until the rotor is pointing at #1 when you set it back down in the block. It is trickey to do.
there is no hard fast rule here. but typically with the cap off and number one cylinder at TDC on compression stroke. the rotor will point at number one cylinder on the engine.
On the Ford 200 cubic inch straight 6 cylinder engine , the distributor rotor turns CLOCKWISE