Overheating 351W-Help!

Yes, you are right, because as the rotor tip is passing the stud on the cap, which probably takes about 3 degrees of rotation, since the rotor tip is wide and the flatted portion of the stud is somewhat wide too, the spark occurs SOMEWHERE WITHIN this time period, governed by the instant the window in the rotating metal cup on the distributor shaft begins to pass the Hall Effect Sensor. This turns off the voltage to the coil, and the collapsing magnetic field inside the coil causes the spark pulse.

Does that sound right?

Tom of the overheated engine.

You understand it very well.

it is either the low to high transition or the high to low transition of the shutter vane passing the hall effect that signals the ignition control module to break current flow thru the coil primary circuit causing the magnetic field to collapse which induces a high voltage in the ignition coil secondary.

The distributor cap and rotor have nothing to do with ignition timing.

you are an idiot.

"Tom" wrote in news:4aa75e64$0$31272$ snipped-for-privacy@cv.net:

Hey dufus, he just explained it to you and you still don`t get it. Try getting a clue and learn someting instead of defending a incorrect position. In your simple terms---YOUR WRONG!!!!!!!!! you can affect the phaseing of the cap but not the timing at all. KB

There are 2 distinct sections to a distributor-

The low voltage section which is below the cap and rotor. This section controls the spark timing, either by using points (remember them?) or a Hall Effect Sensor or similar electronic device, to open the coil circuit and provide the spark pulse, to spark the plug. By turning the distributor relative to the engine block, this changes the timing of when the spark occurs relative to the piston position.

The high voltage section is composed of the cap and rotor, and is like a large selector switch . The spark pulse comes in through the center post on the cap and through the rotor via the springy finger on it. The tip of the rotor then sends the spark to one of the plug wire towers that it is nearest to, and then down that plug wire to the spark plug. The rotor tip is wide and the tower post is too, so there is about a 5 degree interval during which they are close enough to send a spark across them. Within that relatively wide interval, the lower portion triggers off the spark at an exact time to make the engine run right.

The distributor cap and rotor could be run off a different shaft than the points/hall sensor stuff, and the engine would still run the same.

It is only out of convenience that they are both driven by the same shaft.

Somewhere in history there probably was a car that ran them separately.

TheModel T Ford had 4 separate coils, each connected to a spark plug, and its "distributor" (I think it had a different name though), turned the low voltage of each coil on to fire the plug.

Nobody here is an idiot. This stuff can be confusing as hell.

Tom the hot engine guy

I know what a capital letter is...

Please explain exactly _how_ you came to this conclusion. Use all of the screen space you need.

Please explain exactly _how_ you came to this conclusion. Again, use as much screen space as you need.