Interesting question and application. First thought it would have been a retro fit, seeing mobs like GM and Ford already had sizable engines already when the jailbars first came out, (not long afterWW2). But then again, they were great tinkerers also. Dave
What size were these jailbar Hercules? As say compared to later F trucks? 300-400-500-600 e.g. Didn’t Ford make a larger flathead V8 at war’s end? Before the big block OHV engines appeared? Or, was the Hercules simply the diesel option? Dave
The Hercules was probably the DJX..only about 90hp from memory....The jailbars had a 239 flathead ,but with standard shell bearings ,adjustable tappets ,and a conventional distributor at the front.Same hp as the Mercury ,IIRC.
Information taken from an original sales brochures.
Ford Thornton Tandem Drive (1947). Gross weight Tray Truck 29000lbs. Gross weight as a Prime Mover 44000lbs. Advertised as two sets of two speed axles, plus a two speed transfer case, giving a selection of sixteen forward and four reverse speeds. Engine Hercules Model DJXC (298 cub. in.) can be supplied with a wheel base of 171 or 211 inches. for tray length of up to 20 feet. Distributed in Australia by J.J, McGrath Aust. Pty Ltd. (Was this McGrath Trailers?)
Bobby Addison and his father knew JJ Mc Grath quite well .....the story they did some fencing for him,and cut around about 40 acres on his land........the woman owned next property ,waited the 10 years and put in a claim under the adverse possession law in Victoria.......Mc Grath was chasing the Addisons to say in court the woman put them up to it......The Mc Graths were supposed to be yanks ,and also owned sandpits in the Kerang swamp ,when the war came ,he went to his supposed congressman in Virginia,and got the yanks to build a factory on sandpit land...The story goes ,the yanks gave him the factory at the end of the war,but Freighters had worked with the Australian govt ,who wanted every penny back,and sold them up when they refused to pay......Mc Garths always claimed in ads that they owned rolling mills in W Virginia,USA,that made his trailer chassis.