I tried it and could not get it to happen, I might be doing it wrong. but it did what it was suppose to for me. maybe another mod installed or only a certain version of buildcraft is doing it.
Got the same issue, the engine "produces" 750 eu per redstone tick and can reproduce it with every engine, but only the small engine give the energie back to the batbox, all ohter engines just charge themselves, realy fast!
But I got another issue too: With in creative mode the Petrochemical Generator is 30000 times in the itemlist, everytime with a higher :xxx value. starts at 212(:0) and goes up to 212:32767. It is a bit annoying because the itemlist is incredible long. I dont know if this is a Forge/Modloader/ModloaderMP bug, but it definitly is not because of other mods.
I am using BC2.2.12 and IC2 1.64, does anybody have this bug too?