Quick Magmatic Engine control question

[wildc4rd]

Just a quick one, I have a fairly orderly pile of magmatic engines supplying my MJ needs, but have over-engineered somewhat to allow for busy periods. While any oversupply just goes right back into lava via crucibles, I'm also starting to get an oversupply of lava! What is the easiest way to switch 30 or so engines on a single switch? I can isolate the lava supply to banks of engines, but they still take ages to empty their internal 4 bucket tanks.

Thanks in advance!

 

[Abdiel]

If you use redstone conduits, the engines will slow down automatically when the energy is not being used. Alternatively, just a long line of redstone wire.