I am addressing the direct current and it will be in the next release. Assuming that you're using 2.2.X of Buildcraft however, you should just use redstone engines. If you are using BC 1.8.1.1, however, I would advise against the use of piping items in/out as the implementation does not work. It will attempt to pull from the input first, so it's not a good idea. Sorry for the trouble.
-looks- Hmm, I'm using 1.8.1.1... Let me fix that xD