KJ66

Specifications

Diameter:  110mm
Length:  240mm
Thrust:  75 Newtons (16.77 lbs)
Max revs:  117,000 rpm
Temp:  570 deg C
Weight:  0.93 KG

Design

Kurt and Jesus Artes have jointly developed  this small turbojet learning from all the recent knowledge gained from the previous designs. This  design is a huge improvement over the FD3 64 giving a power 3 times as much and at much lower temperature. The engine can still be built in the average model engineers workshop and still uses the gas canister for the outer body! The design uses a turbocharger compressor rather than the home made wooden wheel of the earlier design. The diffuser assembly is CNC machined in the original example but there are ways of machining/ fabricating the design with the Myford lathe.

       


Materials

The front of the engine is all aluminium and the compressor a turbocharger. The combustion chamber is stainless steel (UK 316 or 310 spec) the NGV assembly at the rear and be made from Inconel if longer life is required. The turbine wheel used is the cast one from Jesus Artes in Inconel 713 and the shaft is tool steel.

   


Compressor

The engine is specified with either the KKK5326 2018 or 2019. The main difference between the 2 is that the 2018 is cheaper than the 2019 and the 2019 has a wider inlet area, so has higher throughput.

Turbine wheel

An engine like this needs a well made properly profile turbine wheel to make the most of its potential. Part of the secret of its very high performance/efficiency is the turbine wheel design. The wheels are available either in cast form and not drilled out or completed to a finished size. The balancing is achieved by grinding the small raised ring cast into the face of the wheel



Bearings

The engine uses the same ISO 608 bearings that the Kamps engine now uses. The grade is C3 with fibre-glass cages and they will stand up to 120,000rpm with the proper oiling and cooling built into the design. Ceramic bearings in small turbines are now becoming standard as the price falls and they become more available. The bearing tube is aluminium.

KJ-66

This is a powerful engine and the first time builder should aware that it will require a reasonable size model. We now have a complete range of Turbine designs that will power both small and large models. The EGT is low enough to install internally in a fuselage.

Plans

Unfortunately the plans for this engine are no longer available.