The general opinion today is that engines need a supply of still, fresh, air at a constant temperature and pressure to achieve maximum reliable power. So modern bikes mostly with fuel injection have complicated and rather large airboxes. When it comes to our thirty year old bikes the same belief prevails, but I wonder how true it is. Those of you who grew up in the sixties and seventies will remember that all British bikes breathed through open carburetors, and racing bikes especially had great huge gaping bellmouths. Now the function of the air filter as opposed to the airbox is to reduce intake noise and (obviously) filter out heavy objects of impurity from the air. Our bikes were built with air filters that conveniently lived in a big box. The point I am getting too is that if for example the amazing 1966 250cc Honda 6 cylinder racer could manage 152mph at 18,000rpm on open carbs then air buffeting could not have been a serious problem surely? By 1975 the square four 2 stroke 5oocc Suzuki racer was hitting 175mph without the benefit of air filters or boxes. The Ducati super sport road bike boasted two huge Dellorto’s with just a minimal bit of mesh covering the intakes to keep small animals from getting sucked in.
So in the interests of science I would like to know if anyone runs unfiltered carbs or just pods open to the air on all sides. I still intend to make some light alloy side panels for my k1 and see if there is any difference over the plastic all encompassing panels.
