Well, I'm not a special effects expert but I would assume a bomb placed between the engine block and the firewall would indeed push the engine forward. One plac

Well, I'm not a special effects expert but I would assume a bomb placed between the engine block and the firewall would indeed push the engine forward. One placed beneath the engine would seem to push it upward. Until placement (big if on placement in the first place) is determined, it doesn't seem likely to be able to explain the results.