FLAT AS A PANCAKE
When Sentinel brought us flat four and six-cylinder diesels under the chassis in the 1940/50s, several advantages were claimed. Quiet cabs, ease of maintenance and better weight distribution were chief amongst them. Sentinel had been making underfloor-engined steam wagons for over thirty years by that stage so plainly knew what it was talking about. Steam had the advantage that you could pipe it to wherever the motor was, though there were plenty who advocated overtypes with the engine next to the boiler though this resulted in a tortuous journey for the transmission (usually accomplished by chains) to the back wheels.
Steam, of course, gave way to diesel from the late 1920s using internal combustion engines placed under a bonnet or protruding through the cab floor. Flat engines were known about in the earliest days of motoring, having been invented in the 1870s and commercialised by Benz in 1885. Indeed, anything went in those far-off days, and certainly lots of veteran cars and commercials such as Benz had their cylinders on their sides. The advanced NW lorry of 1898 (a forerunner of Tatra) actually had twin Benz motors under its tail.
Herbert Austin was a passionate horizontal engine advocate whilst running Wolseley and, having won the 1900 Thousand Mile Trial, he introduced racing cars with flat fours giving a very low centre of
