Idle speed is simply controlled to an rpm value, which thus makes it tied, loosely, to the CPU clock. The phase noise is quite awful, by anyone's standards, mainly because the parameters measured to control fuel and spark timing, are noisy.
Tom Holmes, N8ZM -----Original Message----- From: time-nuts <[email protected]> On Behalf Of Hal Murray Sent: Saturday, February 06, 2021 9:48 PM To: Discussion of precise time and frequency measurement <[email protected]> Cc: [email protected] Subject: [time-nuts] Anybody plotted the ADEV of a V8 idle speed? [email protected] said: > Although Mr. Wineland's IQ must be at least 50 points higher than mine, we do > have something in common. I too owned a '36 Ford in my youth, about the same > time as he did, although mine was a Cabriolet not a coupe, and I fitted it > with an OHV Studebaker V8, a smaller displacement clone of a Cadillac V8. Speaking of V8s... Just a simple graph of idle speed vs time for the first few minutes after a cold start might be a fun high school science project. Is the idle speed of a modern warm engine locked to the CPU's crystal or is there a feedback loop setting some pollution or mileage parameter? In the old days (pre computer), there was some thermal input to the idle speed. I assume it was a bimetalic element. -- These are my opinions. I hate spam. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_l ists.febo.com and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
