If you want to power a rolling machine from a redstone engine, use more then one. The rolling machine loses a bit of power over time, and just one redstone engine cant keep up with the power loss. Use like 5 redstone engines. Or just set up an old forestry arboretum and logger. If you pipe those into eachother and a fermenter correctly, you can produce enough biomass to continuously run 9 biogas engines. Just don't let the fermenter run out of compost, or the arboretum run out of humus. 2 engines to run logger and the other 7 to run whatever MJ powered stuff you want. Redstone energy conduits are your friend here.