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Dumb question for you smart guys.
I've been reading all of the spark timing
information with great interest. We have a while before we have to settle on an
ignition system for our non TC 550 and, of course, would like to make the most
informed decision. Soooo, George, Scott, Hamid, Paul, Rick, et al, how about
this:
Seems to me that rpm changes
effectively adjust ignition timing. For example, if you're running at 2500
rpm and the spark occurs at 25 btc, the flame propagates at a rate that produces
max pressure at some point after tdc, lets just say 15 degrees. If you reduced
the rpm to 2200 and the spark occurred at 25 btc the flame would propagate at
the same rate as before but the piston is moving slower. Seems to me that the
max pressure would occur at somewhere less than 15 after tdc, effectively
advancing the ignition.
Most agree that the majority of the advantage of
adjusting spark timing happens at lower power settings. To me, it looks
like the advantage is better fuel economy as opposed to more power. Couldn't one
simply pull the prop control back to gain this same advantage?
Probably lots of flaws in my thinking, but I'm not
smart enough to see 'em. Help me out.
Bill Harrelson
N5ZQ 320 1,100+ hrs
N6ZQ IV 4.239%
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