Re: Timing Question about 5682s

Posted by Owen_Dyneto On 2013/8/20 6:13:40

JP, just to clarity with regard to engine numbers. There are two, the "motor number" which should match the vehicle number, and the Utica Plant number. The Utica number is sequential for the particular engine type (the prefix letter) and then numbered sequentially. The service bulletins and counselors which refer to running changes in the engine use the Utica numbers to show at which number certain change were made; of course the motor numbers can't be used for that purpose and the finished engines weren't necessarily installed in the same order that they were produced.

As noted, the very best method for timing correctly is the "by ear" method finding that point at which "ping" is barely noticeable under hard acceleration with a hot engine. Doing it this manner eliminates the issues of changes in compression ratio from prior engine rebuilding (decking, head resurfacing), gasoline brands and octanes, spark plug choices, etc. My 56 Carib does not tolerate 93 octane premium with timing at 10 degrees but gives good performance with no excessive ping at about 7 degrees. It would be unrealistic to find a single timing which is best for all engines even of the same type