Shortround is right : it is likely that Jane's mixed several sources and datas for weight, power, etc.. In practice, the Sterna never exceeded 900 hp.
However, it had several interesting features as the 4 valves per cylinder, unlike the competitor Hispano-Suiza 12 Y. But its supercharger was out of date.
The Lorraine company was dying in 1936 and was definitively killed by the nationalizations. Its Technical director, Claude Bornier, worked essentially on carburation and exhaust gas analysis.
Regards, Alain