The
L2800/3400 have 3cyl engines. The
B3030 has a 4cyl eng.
ORC is "over running clutch" for the PTO.
Here is a good explination of PTO clutches. This is not my definition so I can't take credit for this knowledge.
A live PTO, by definition, continues running when the operator changes speed or direction. Whether a live PTO is needed depends upon the work a tractor will do. Any stationary work (chippers, generators) does not need a live PTO. Large mowing operations where there is little backing up do not need a live PTO. Snowblowing, rototilling, and other applications where changes in speed and direction are important a live PTO makes the job easier.
There are several ways to make a live PTO work.
The first way is a two-stage clutch. In this case when the clutch is pushed halfway in the main transmission is disengaged. When the clutch is fully depressed the PTO and the main transmission are disengaged. The PTO cannot be engaged or disengaged unless the transmission is disengaged.
The second method is making a live PTO is through a separate clutch for the PTO (live independent). This method allows the PTO to be engaged and disengaged regardless of whether the tractor is moving or stationary.
The third method is live continuous. The main clutch disengages and engages the PTO. However, due to the transmission, the operator can change speed and direction with out using the clutch, i.e. Glide Shift or Hydrostatic transmission.