A VTEC rocker arm has been produced from aluminum die-cast materials to reduce weight and lower cost. The new arm, like the majority of rocker arms in use, employs a roller follower to reduce drive friction loss in the valve system. The VTEC connecting holes, in which strength must be guaranteed, were focused on to enable the shift to aluminum in the new VTEC mechanism. A coaxial roller structure with a hollow roller bearing shaft was adopted, allowing the roller shaft to be press-fit into place and ensuring sufficient strength and accuracy in the new rocker arm. As a result, both the weight and the cost of the new rocker arm have been reduced by more than 20% against the former forged steel arm. The new arm was then first mass-produced for use in the Fit.
Article of Honda R&D Technical Review Vol.15 No.2 (47 - 52)