In the year 1991, Bugatti debuted their EB110 which was meant to be as high-tech as a car can possibly be. It boasted off a daring five valves per cylinder. In the year 1994, Ferrari followed their suit with the V8 355 having forty valves, then their own V12 F50 having sixty valves a year later. However, both of them were beaten to a punch by none other than Mitsubishi.
In the year 1989, Mitsubishi debuted it’s little MinicaDangan ZZ which was a kei car having three cylinders. This was the very first five valve per cylinder production car, and it kind of made sense.
Designs having five valves per cylinder are not easy to engineer, however, they do offer better breathing for an engine, along with being good for high power, having high efficiency as well as high RPM. The idea seems simple but the execution is not.
For example, if one of the valve for intake and one of the valves for exhaust is good, then two for intake and one for exhaust is even better. If 2 valves for the intake and 1 for the exhaust are considered good, then 2 for the intake and 2 for the exhaust is obviously better. If 2 valves for the intake and 2 for the exhaust can be called good, then 3 for the intake and 2 for the exhaust have to be best!
The main problem is that the space gets tight at the point at the top of the cylinder, and the gains are slightly over the four valves per cylinder. The tech time of five valve in the sun was bright, but short-lived, as everybody realized that the cost was not really worth it.