1. Setting Ignition Timing

    This is probably elementary to most out there, but I had an epiphany and thought I would bounce it off the board to get some thoughts.

    I just put a new cam, lifters, timing chain, etc. in my 258 to refresh it a little. While setting the timing marks and such, I realized the true meaning and relationship of TDC. The key on the crank makes it the power or exhaust stroke by the location of the timing mark on the crank gear. When the cam gear mark is aligned at TDC and slipped on the cam pin, that sets the cam in proper time with the stroke on the crank.

    When inserting the distributor, it really doesn't matter where it was, or where the book says to put it. It really comes down to inserting it in such a way that when any cylinder, usually easiest to pick number one, is on the power stroke, (TDC) mesh the gear in such a way as to align the rotor with that cylinder's location on the cap when fully seated. It's easiest to go by the book so the next guy knows where you put it, even if it's you, and use #1 and keep #1 the same location on the distributor. The distributor doesn't care where #1 is, as long as the cam/crank and plug wire match when it's at that location. Connect the plug wires following the firing order in a clockwise fashion, done.

    I never knew that timing really made so much sense.

  2. #2

    Re: Setting Ignition Timing

    True only on a non fuel injected engine and a non electronic ignition system however, TDC still has to be on a compression stroke, the firing order still needs to be followed in it's proper sequence of ignition within their respective cylinders. In some cases, where the distributor doesn't have any obstructions around that requires it to be clocked at a certain way, you can pick and choose which one on the distributor cap will be designated for the #1 spark plug.
    Confucious says: Don't eat the snow where the huskies go!

  3. #3

    Re: Setting Ignition Timing

    Yep, true dat. Even after the moment of awareness, I still put the the dizzy in 180 out. Turns out that even by aligning the marks on the gears, you aren't guaranteed that is the compression stroke. Nope, that would be when the marks are at 1 and 3 with 15 pins between, apparently.

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