Westport Innovations Inc has completed a US$54-million equity offering of 4.5 million common shares which it will use for R&D and market development of its low-emissions diesel engines that burn natural gas. The financing is the second in just two months and follows a $15-million offering of 15,000 debenture units convertible into common shares. Westport is also in two joint ventures with Cummins Inc for commercial transportation applications and Beijing Tianhai Industry Co Ltd for the manufacture and sale of vehicle fuel tanks….