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Hey Bruce,

There's a good passage in that book you turned me on to, Robert Bosch's Electric and Electronic Systems in the battery ignition chapter, p. 106, starting with "Thus, the dwell angle is permanently preset for a breaker-triggered ignition system and is invariable throughout the entire engine-speed range. However, the dwell angle does change throughout the service life of the engine owing to wear of the cam follower on the breaker lever. The abrasion which is thus produced means tnat [sic] the contact breaker opens at a later point. The resulting ignition retard generally results in higher fuel consumption."

He goes on to describe the effect of contact erosion and "undefined" ignition points leading to "higher fuel consumption and poorer exhaust-gas values".

My take on increasing dwell intentionally (leaving timing the same) is the result will be felt at higher rpm as a detriment, as most attempts to "redesign" something do.


--
Art Benstein near Baltimore

Always wanted to use [sic] in something ^_^