It has been factory modified with an internal oil passage in the H23A block to operate the VTEC solenoid in the H22A head .
In 1998 , Honda of Japan produced a rare DOHC VTEC version of the H23A engine for use in Japan only .
It has been factory modified with an internal oil passage in the H23A block to operate the VTEC solenoid in the H23A head .
In 1998 , Honda of Japan produced a rare DOHC VTEC version of the H23A engine for use in Japan only .