These machines are drain jetters which use massive pumps about 3-4000psi and flow rates at about 60l/min. they require a big engine to run them but for some reason they use engines that are too big. These pumps actual require about 28-30hp. They have a lot of spare power to run a blower.
Having a big pump is amazing for powerwashing, you can clean very fast ( if you have a big water tank or the outside tap has good flow) but you don’t need to use the full power.
I don’t understand why these Diesel engines are not used for truck mounts, they last longer and are much simpler in design. you can find 3-4 engineeers in any town that can fix them