Super the valve ban sign !!!!!!!
I dare an explanation for those who do not know the NR:
The NR was initially a good idea. Fighting against the ever-increasing power of 2 tps, Honda engineers, loyal to 4 tps, were looking to improve filling. The solution was found by lengthening the piston, so they could implant 8 valves (see photo of a series NR piston in christophe's post). The problem was that reliability was never at the rendezvous. The most mocking nicknamed her the Never Ready. In fact, besides the fact that it heated a lot, there was an obvious problem of guiding the piston on a single connecting rod. Never admitting to being defeated (it's a philosophy at honda) the engineers design a new mobile crew to 8 rods (yes, 2 by pistons). The efficiency gain thanks to the multiplication of the valves is finally lost because of a very heavy and very complex vilo and the weight of 8 connecting rods. Honda then switched to 2 tps with a 3 V-cylinders.
It was still necessary to do something about all the innovations and technologies developed since all these years. And above all it was necessary to ammortir the very expensive machine tools made exclusively for the manufacture of pistons, segments and cylinders not cylindrical
It was at this point that it was decided to produce an exclusive machine, with a lot of noble materials, a sort of technological showcase for the brand. Several years between the first photos and marketing, exorbitant price: all the ingredients to create a myth. The series bike is not exceptional in terms of performance 750cm3, 135 ch; a 900 CBR of the same era does the same for 6 times cheaper!
Having worked in a Honda dealership, I had the chance to go to honda france several times, at the training center, in the classroom, there is a showcase with the most beautiful parts of the manufacturer. Of course there is a piston like the one in the photo. I could not resist asking to touch him. After finding the key of the famous showcase, I could hold in my hands this fabulous piston, and a F1 turbo. Almost on my knees, I had tears in my eyes. It's not common for simple mechanics (like me) to have access to such parts, my daily life is rather emptying, tires and pads