As an engineering student lam particu larly interested in air-cooled
Page 75

If you've noticed an error in this article please click here to report it so we can fix it.
engines and have heard that it is possible to cool the cylinders with the exhaust gas. This sounds absurd. Can you enlighten me?
A The exhaust gas of an air-cooled engine
can be used to cool the cylinders by creating a draught of cool air over the fins. A venturi-type duct is attached to a cowling surrounding the cylinders and the exhaust gases are discharged into the duct. And this creates a suction that draws air over the fins.
As far as is known, the only engine manufacturer who has employed this system (experimentally) is the Tatra company of Prague. It is understood that the system has been successfully applied to a single-cylinder engine of the motorcycle type.
It would, of course, be possible to drive the cooling fan of an air-cooled engine with a turbine energized by the exhaust gases. Employing an exhaust turbine to drive the auxiliaries of a diesel-engine, including the generator and fan, has been mooted from time to time. As in the case of a turbocharger, a turbine would not absorb useful power and such an application would eliminate a substantial source of power loss.