JET-Antrieb 5 Graupner 2347 The JET propulsion unit 5 is a development of the JET propulsion unit 4. A re-design of the steering nozzle and reversing flap have produced a much lighter version of the JET propulsion unit. However, since the shape of the JET unit housing is the same as that of the JET propulsion unit 4 (Order No. 2348), it can be used as a simple replacement for the preceding model. The inlet tube and thrust nozzle are made of very robust pressure cast aluminium, while the plastic parts are moulded in glass fibre reinforced material. The impeller shaft runs in twin ballraces. The new JET propulsion unit is ideal for internal combustion engines, as thrust reversal is obtained by operating the reversing flap rather than by reversing the direction of rotation of the engine. The steering nozzle incorporates an integral cooling water nipple. Suitable power plants are internal combustion engines of 15 to 30 cc capacity, and electric motors rated at a minimum of 700 Watts output power. The steering servo must be a powerful type we recommend one with an output torque of more than 5 kg/cm (e.g. C 4621, Order No. 5126). If you wish to install the JET propulsion unit 5 in an AZIMUT ATLANTIC CHALLENGER and power it with an internal combustion engine, you will need to reinforce the hull with two layers of 300 g/m2 glass cloth, seal off the four stern openings by laminating glas