During WW2, a German plane, the Focke-Wulf FW 190 outperformed any fighter plane the Allies could build. That is until the Hawker Typhoon and Hawker Tempest were released.
A major reason why the Hawker aircraft were so superior had to do with the fact that they contained powerful sleeve-valve engines. In fact, it wouldn’t be farfetched to say that the sleeve-valve engine helped the Allies win the war.
In 1901, Indiana-born, small-time publisher Charles Yale Knight purchased a Knox automobile so that he could distribute his farm journal in the local area. The car proved useful; however, he eventually became annoyed by the noise created by its tappet valves. What did he do about? Well, being the technically-talented person he is, he set out to build a better engine.
With support from a wealthy backer, Knight prototyped an early sleeve-valve engine and made enough progress to reveal his “Silent Knight” car at the 1906 Chicago Auto Show. True to its name, the Knight was very quiet for the time, and soon garnered the interest of several manufacturers who wanted to license its impressive technology.
A car historian friend of ours at Kims Chrysler of Laurel, a local Chrysler, Dodge, Jeep, Ram dealer in Laurel, MS, told us that Walter Chrysler was one of the first to express an interest.
How Sleeve-Valves Work
First and foremost, the engine gets its name from the metal sleeve that slides up and down within each cylinder. Rather than using “poppit valves,” holes in the cylinder sleeves line up at predictable intervals to suck in fresh air and expel exhaust.
Although more complex internally, sleeve-valve engines are a lot better than regular engines at getting air in and out of their combustion chambers. Moreover, the arrangement of their sleeve ports provides better swirl characteristics during combustion, meaning turbulent air is created in the combustion chamber to allow the air and fuel mix to burn more efficiently.
After decades of rest, the sleeve-valve engine is back again. San Carlos California-based Pinnacle Technologies is working on a new engine based on what the company describes as a four-stroke, opposed-piston, sleeve-valve design, with company founder Monty Cleeves claiming it can yield a 30- to 50-percent efficiency improvement over current engines.
But Aren’t Electric Vehicles The Future?
Pinnacle says it isn’t worried about the increasing proliferation of electric vehicles, which will eventually make internal combustion engines obsolete. Western society is gearing up to go electric, but third-world countries aren’t quite ready for the automotive new age.
India, China and other developing countries aim to curb greenhouse gas emissions while improving their citizens’ standard of living through motor vehicle ownership. Considering electric and hybrid vehicles are still very expensive, Pinnacle hopes its re-envisioned sleeve-valve is a good “bridge technology” until electrics become more affordable for everyone. It will be quite a while before that happens in the third-world.