Well I was thinking to have a tank for storing fluids before go to the engines is more efficiency, so why not having something like a battery( that can stack up like tank) and store the energy left from the engines, so there isn't energy loss.
(sorry if my English isn't good, it isn't my native language)

Not the place for suggestions.

If you want to store energy (BC) in Portable form then search for TinyChest. That has it

ok thanks and sorry.

mod sugestions go here: http://www.mod-buildcraft.com/forums/forum/feature-ideas/