Single Cylinder Flathead Engine Shop › Forums › Completions › Single Cylinder Flathead Engine This topic has 0 replies, 1 voice, and was last updated 4 years, 9 months ago by Don. Viewing 1 post (of 1 total) Author Posts February 24, 2020 at 2:06 am #78 DonKeymaster This was the original prototype “Flat Flathead” engine. It took only a couple of hours to build. It was the third wooden engine I designed. Author Posts Viewing 1 post (of 1 total) You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In