Re: adjusting the timing for changes in altitude

Posted by JWL On 2011/12/14 21:50:29

John, adjusting the timing for high altitude was a common practice back in the day. However, the timing changes we made were only a couple of degrees and this was for 7,200 above sea level altitude. I doubt you would need to change the timing for 5,000 feet.

However, if I recall correctly, your Packard has an "Octane Adjustment" feature on the distributor. There is a scale, a pointer, and a thumb screw at the base of the distributor where it mounts to the engine. The scale is marked with an indicator for top dead center and marks on either side for advancing or retarding the timing. This allowed the driver to easily change ignition timing, without having to use a timing light, to cope with varying quality fuels back then. Timing could be advanced or retarded to get optimum performance on the fuel available. By remembering how many marks the pointer was moved, the initial timing could be reset by going back to the original location. I think all of this is described in the owner and service manuals.

(o[]o)

Edit: Kev, this question would be better served in the General or Pre-War section.