Overview of the Internal Combustion Engine
The model T Ford was one of the first mass produced automobiles to be powered by an internal combustion side valve engine built by the Ford Motor Company beginning in1908.( A well known slogan – any color as long as it is black?)
From 1932 they used a modernized version of this engine in their model Y autos. As an aside, the electrics were powered by a dynamo and the windscreen wipers operated by a vacuum from the carburetor manifold. I remember these well on Dad's 1950 Morris Minor; the wipers used to slow down as the engine labored up hills!
On the motorcycle front Harley Davidson used a side valve engine as early as 1919. The Davidson partner originally came from quite close to my village, and every year we have a Harley Davidson Rally with Bikers from all over the world attending – a great day out in the Highlands of Scotland!
Anyway, to continue, overhead valves and overhead cams (OHV and OHC) had been around for a while as well, but not exploited commercially until 1927 when Standard Motor Company introduced their V6 OHV engines, followed in 1949 by Oldsmobile. They produced an OHV engine operated by pushrods and fitted to their Rocket V8, but before that Norton Motor Cycle Company had produced a single OHC engine between 1925/26, that won the 500cc Isle of Man TT race in 1926.
The pent roof combustion chamber was reputedly used first in the engine of the 1904 Welch Model 4.0 built by The Welch Motor Co., Pontiac, Mi.
Pent roof combustion chambers were also used by Chrysler between 1951 and 1958 when it was discontinued due to high costs. Honda Motorcycles were using the pent roof combustion chambers around 1962, and I well remember Mike Hailwood, their star rider and world champ pushing a 500cc Honda out onto the start grid at the Ulster Grand Prix. We were all looking out for a “Honda Six" at the time and this machine had six exhaust megaphones poking out from the engine. Mike sort of smiled at the cluster of photographers and dolly-birds around him, reached down, and removed two dummy exhausts – yep it was still the four cylinder model!
A 1966 version of the Honda 500cc ridden by Mike is shown below;
Anyway, this was probably the first of the pent roof multi-valve engines produced by Honda and it blew all the opposition away in TT racing: the emerging Yamaha and Suzuki two-strokes, even our old Irish current record holder, a 7R AJS rode by local hero Dick Crieth.