[Martin Ducati Glasgow]

Originally Posted by twpd

Because it's not a level playing field for a twin. I don't see how this is so hard for people to understand. cc for cc a twin cannot compete with a 4 and the reason for this is that the 4 has more valve area - it is valve area that largely dictates how much power is produced. 4 small high-revving pots will give more power than two large lower-revving pots.

The easiest way to get more power out of a 4-stroke is to increase the valve area i.e the bore and the size of the valves, and shorten the stroke to allow it to rev harder. This is why 4 cylinder bikes make more power per litre than twins.

It's quite amazing that Ducati can compete as they do with the 999 but it costs them a fortune in engines because they don't last long. They want to go to the bigger motor to save money and have restrictions placed upon them re. the amount of tuning they are allowed to do. I get tired of people saying Ducati cheat - they don't. They work within the rules which, have been agreed by all the factories including the Japanese factories. A well-known Yamaha race engineer once said that if the rules were properly applied then the 4's would be restricted to 738cc whilst the twins were at 1000. I will try to find the reference.

Well said that man!!