![]() ![]() ![]() I suppose you could use a timing light and watch when the strobe flashes. Now, slowly rotate the distributor until the plug fires. Use a spark tester or even a spark plug that is grounded.put the #1 plug wire on it. You know you have 20 in the distributor, so you'll need 16 degree initial.īump, use a socket, or otherwise set the timing mark on the crank to 16 degrees on the timing tab. So you're going to set the intial, or base, timing.ĭecide what you want your timing to be, in this case, let's say you want a total of 36 degrees. Here's the easiest way to set timing without the engine running:įirst, you have to know how much advance (centrifugal or vacuum) your distributor has.Ī typical performance or OEM dist. And that'll make the TDC mark appear to move, as you mentioned. It's kind of like convergence on a CRT, you get one edge perfect, and the other edge is too red, make that edge perfect and the other edge that used to be perfect is now too blue.Ĭlick to expand.Technically speaking, the light flashes at the exact same time regardless of what the timing is.īut yeah, you are changing WHEN the #1 plug fires in relation to the piston by adjusting the timing. What makes it tricky with mechanical ignition (distributor) is adjusting timing over the whole range, not just idle. Almost a must when you are timing at high RPM for top end, as the tab isn't wide enough or the pulley/hub/balancer isn't degree'ed that far to show dynamic timing advance at wide open. You always time the mark on zero on the tab, so if you want 18 deg advance, you set your ignition to 18 degrees advance (which would show the mark 18 degrees ahead of zero with a regular light) program the gun with 18 degrees of delay (ie: make the strobe 18 degrees behind or out of phase with the actual spark) so that you are still timing to the same 0 mark instead of a scale. These require a timing light that has a degree dial. Some don't have scales on the tab, they just have a single mark. If it was 12 deg instead, you'd adjust the distributor (or knob or whatever means the ignition system allows) to advance more, and you'd see the stationary line move under the strobe and you'd dial it in until it showed 15.Īll it's doing is showing you a freeze frame of crank position in degrees BTDC at the time the spark occurs, the definition of ignition timing. Say you want 15 deg BTDC and wanted to confirm, you would note if the crank mark is at the 15 deg mark on the tab. ![]() But if you were to adjust timing while firing the strobe you would actually see that stationary line move up and down the scale on the tab in proportion to your timing adjustments. If you just strobe the crank pulley you will see a static line landing at some spot on the stationary indicator tab. When you adjust timing, you are changing the part of the crank that is captured on the strobe by making the light flash early or late. It will also flash in the same spot every time making the crank appear to stand still. Not sure if it's clear to you yet, but when you change ignition timing you also change when the light flashes since it uses the spark plug wire as a trigger. ![]()
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