There is a conventional wisdom that has developed around intake valve configuration: cylinder heads equipped with ports inclined at narrow valve angle to the valve stem should have conical, or ‘tuliped’ back faces, and ports that have significant bend at the intake valve should have shallow back angles i.e. the classic ‘nail head’ shape present in so many large pushrod engines. While this is true much of the time, there are exceptions, and frequently the desired point...
Recently, RET has covered valve spring design and measurement extensively, but it is almost impossible to discuss valve spring design without mentioning the desmodromic system which is used nowadays exclusively by Ducati.The term Desmodromic is coined from the Greek words ‘desmos’, which means ‘controlled’, or ‘linked’, and ‘dromos’, which means ‘course’, or ‘track’. In modern engineering terms desmodromic refers to a...