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By dbird - 14 Years Ago
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I can find no timing marks on my crank pulley. When I changed the distributor, I set the timing with a vacuum gauge and for checking accessories or driving around the yard, everything is fine. However, when I hit highway speeds, I'd like to do better than advance it until it pings then back off. Is there an easy to find TDC without disassembling much? Once I mark TDC, marking degrees seems like just a measurement. 57 block with an unknown dual groove pulley. Correct spacing for a Thunderbird, but there are no marks that I have found.
Thanks,
Don
55 Bird in the Valley, still waiting for the chrome shop
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By rick55 - 14 Years Ago
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The vacuum gauge method works as good as timing marks.
Whilst reading the vacuum gauge at idle, advance the distributor til you get the maximum steady reading, then retard the ignition 1" of vacuum.
Works for me. I have never worried about timing marks.
Regards
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By Ted - 14 Years Ago
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dbird (9/21/2011)
I can find no timing marks on my crank pulley. Is there an easy to find TDC without disassembling much? Once I mark TDC, marking degrees seems like just a measurement.With the valve covers off, catch either the #1 or #6 cylinder where the valves are at overlap and with a level, lightly rotate the engine so that both rockers on either cylinder are open equally. As a FYI, the #1 and 6 cylinders share the same TDC. Overlap is where the exhaust will be closing and the intake will be opening. When you find this point, simply mark the damper with a TDC mark. Although this could be off as much as four degrees in normal circumstances, it will provide a TDC mark that’s close enough to give some ignition timing indications with a light. Then take the damper diameter (6”?), multiply by Pi (3.1415), divide by 360, and then multiply by the number of degrees you’d like for a timing mark and put this in another line above the added TDC mark. You now have a timing mark to use for a reference. If using 10° for the initial timing then that mark would be ~0.524” (half an inch) above the TDC mark.
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By dbird - 14 Years Ago
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Thanks for the input,I was really hoping there was some weird trick that I hadn't heard of. I was curious how close the rockers would get me, thanks for the about 4 degree Ted. I was planning to run the valves soon anyway, so it will be interesting to see how close the two methods come.
I was coming up with all sorts of ideas like hollowing out an old spark plug, connecting a clear hose with a downward loop, getting close then adding liquid and watching for a change in level as I turned the crank, but thought leakage by the rings/valves would throw it off.
Don
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