I'm interested in obtaining information on the Harley-Davidson engine timeline, such as the year the engines were in productivity. I think the flathead started in 1929. Is that correct?
Yes, the flathead began in 1929 till 1936. Next came the knucklehead from 1936-1947. After that was the panhead from 1948-1965. Then the shovelhead from 1966-1985. Next the evolution from 1984-1999 and the Twin Cam from 1999 and on. Hope this helps.