The Ford Barn

29spcoupe · 01-09-2017, 10:14 PM

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If you are not hearing the 'ping' with the spark fully retarded and you hear it when advancing, then the noise is spark related. The ping is not happening because of the compression ratio. Spark knock in higher compression engines occurs because the low octane gas ignites faster under high compression and therefore the adding of higher octane. If your timing is quite close with an ohm meter, is it possible that your distributor cam has moved a little causing the points to open sooner? My feeling is that it is timing. I would check everything again. I would like to hear what others think.

01-09-2017, 10:14 PM	#6
29spcoupe Senior Member Join Date: Aug 2014 Location: Rhinebeck, NY Posts: 779	Re: Snapping sound under load. Sponsored Links (Register now to hide all advertisements) If you are not hearing the 'ping' with the spark fully retarded and you hear it when advancing, then the noise is spark related. The ping is not happening because of the compression ratio. Spark knock in higher compression engines occurs because the low octane gas ignites faster under high compression and therefore the adding of higher octane. If your timing is quite close with an ohm meter, is it possible that your distributor cam has moved a little causing the points to open sooner? My feeling is that it is timing. I would check everything again. I would like to hear what others think.