12-06-2015, 06:15 AM
I've been studying up a bit on our beloved CB, and one of the persistent oddities I discovered was the unusual decision by the engine design team to give the big CB some character by engineering in a little roughness. Apparently, the engine was deemed "too refined" so they retarded the intake cam timing on just two cylinders to give the bike some soul, I guess. Stranger still, they went through the trouble of utilizing a counterbalancer to make the engine smooth! Seems counterproductive.
Anyway, this assymetrical cam timing comes at a cost in achievable top end horsepower I believe, so I'm going to look into this by buying a set of stock cams and taking some measurements. My engine builder and machinist can re-profile the intake cam to a symmetrical timing configuration, perhaps even altering the duration to get more horsepower out of this powerplant. The cylinder head is also modestly configured with relatively small port area, so perhaps some improvements can be made there too.
115-125 hp seems achievable, as long as I can get the engine management system to play with these changes. Anyone else look into this or know about it?
Anyway, this assymetrical cam timing comes at a cost in achievable top end horsepower I believe, so I'm going to look into this by buying a set of stock cams and taking some measurements. My engine builder and machinist can re-profile the intake cam to a symmetrical timing configuration, perhaps even altering the duration to get more horsepower out of this powerplant. The cylinder head is also modestly configured with relatively small port area, so perhaps some improvements can be made there too.
115-125 hp seems achievable, as long as I can get the engine management system to play with these changes. Anyone else look into this or know about it?