Distributor body window opening size
- Thread starter pilotdude
- Start date
Napa Skip
Senior Member
As pointed out in "Ignition Timing - Part 2; Common Problems and Specifications" by Lynn Sondenaa (The Restorer, May/June 2009, page 12) the distributor body plate lever notch should be 7/16" tall x 1-1/16" wide.
However, in Terry M. Burtz' "The Subtle Differences in Distributor Bodies" (also From The Restorer, but I neglected to note the issue date) he discusses his findings while judging the 1984 MAFCA National Convention in Portland OR, where he found substantial differences between the 64 Model A's he judged. He states that from the beginning of production in late 1927 until December 1930, the distributor body design was unchanged with an opening 7/16" high x 7/8" wide and can be identified by having corner reliefs in the window opening. In December 1930 the distributor body was modified to "...a 31/32" wide window to allow the full 20 [degree] spark advance with the flat arm breaker plate."
Bottom line - as addressed in the August 1930 Ford Service Bulletin (page 480; also addressed in Burtz' article) - the distributor body opening should allow for a full 20-degrees travel of the breaker plate lever from fully retarded to fully advanced.
Others may have more detailed or up-to-date information.
However, in Terry M. Burtz' "The Subtle Differences in Distributor Bodies" (also From The Restorer, but I neglected to note the issue date) he discusses his findings while judging the 1984 MAFCA National Convention in Portland OR, where he found substantial differences between the 64 Model A's he judged. He states that from the beginning of production in late 1927 until December 1930, the distributor body design was unchanged with an opening 7/16" high x 7/8" wide and can be identified by having corner reliefs in the window opening. In December 1930 the distributor body was modified to "...a 31/32" wide window to allow the full 20 [degree] spark advance with the flat arm breaker plate."
Bottom line - as addressed in the August 1930 Ford Service Bulletin (page 480; also addressed in Burtz' article) - the distributor body opening should allow for a full 20-degrees travel of the breaker plate lever from fully retarded to fully advanced.
Others may have more detailed or up-to-date information.