Complex sentence: Intake and exhaust manifolds were both duplicated on both sides of the block, and there were four cam-operated injection pumps per cylinder, each driving two nozzles for eight nozzles per cylinder in all.
Split into simpler sentences: Intake and exhaust manifolds were duplicated on both sides of the block. There were four cam-operated injection pumps per cylinder, each driving two nozzles, for eight nozzles per cylinder in all.