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Old 11-04-2011, 06:42 PM   #7
Milton
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Join Date: Oct 2010
Posts: 837
Default Re: Spark advance or Spark retard

Consider a modern car as it comes to an upward incline. The initial response from the engine as it loads is to experience a lower vacuum which retards the timing a given amount. As the load increases even more, the rpm will lower and the centrifugal weights will collapse towards the center shaft and increase the retardation. A downshift will reset the process somewhat in that the increase in rpm will cause the weights to move outward and increase the advance. So your action on an incline is to copy this sequence. I live at the top of a three mile grade so I used to get a lot of practice. When the loading begins I bump up the lever 4-5 degrees and increase the throttle. If the load continues and the rpm lowers I re-adjust until the rpm becomes steady. If it continues I will downshift, bump the advance and go through the adjusting again. If the rpms continues to drop I will turn around, restore the advance, go down and then go around.
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