The new HR-1 engine

After my initial experiences with my first jet engine, I decided to build a new larger engine. This new engine will be called the HR-1.

I am trying something new in that I am bringing in the air in the middle side of the combustor. On my first engine the air flowed axially through the combustor, entering one end and leaving the other. This engine will use an annular combustor in which the air enters from the side and flows out of one end. The design is a bit easier to construct and is also more compact as there is not an excess of pipe to transfer the air from the compressor to the combustor.

Combustor parts

I started by constructing the outer combustor housing and plumbing that will connect the combustor to the turbine and compressor.

Combustor exhaust elbow

The combustor does not flow directly into the turbine, but instead makes a 90 degree turn before entering. This was done to make the whole engine more compact.

End cap flange and air inlet

The air will enter from the side of the combustor. The offset opening of the inlet pipe should help to induce a swirl in the combustion chamber. With the gasses swirling before they enter the flame tube, it should help to create a vortex of fire that sits in the center of the flame tube.

Construction stand

This is the stand that was built to hold the turbo during construction.

Turbo inducer

The inducer on this turbocharger is much larger than on the previous RayJay turbo. With the additional mass flow of air there should be a considerable power gain. The inducer is the area of the blades that can be seen when looking at the inlet of the turbocharger.

Combustor to turbine elbow

The additional length of the the combustor that is added by the bend will also give more time for the burn process to complete before the hot gasses enter into the turbine. Hopefully this will allow the engine to run a bit cooler as well.

Blank pipe for the flame tube

This is the pipe that will be drilled for the flame tube. It is 4 inches in diameter.

The flame tube

Once the holes are drilled, the flame tube is ready to be installed. The hole sizes and pattern were calculated using Jet Spec Designer. A copy of the program can be downloaded from my site and is free of charge to use. Once a flame tube has been properly calculated and drilled, it appears to be almost a work of art.

Combustor end plate

The end plate of the combustor is removable for easy access and maintenance. It is held on with 8 bolts and sealed in place with high temperature silicone sealant such as is used in automobile applications.

The finished engine

Here is the completed and painted engine on the test stand. Note the size of the actual turbine and the size of the exhaust pipe that was used. You can see that the pipe fits the housing but it is much larger that the actual turbine exducer blades. The exhaust flange of the turbine is much larger that the actual turbine blades, since the original application for automobile use would need to slow down the exhaust gasses and pass them through a smaller exhaust pipe section.

The engine ready to be tested

The engine is hooked up to the control panel and ready to run with the addition of the oil pumps and coolers, along with the fuel system. Gauges will be used to monitor pressures and temperatures, in the same way as were used on the original RayJay based engine.

The control panel

The control panel contains switches to control the oil and fuel pumps, as well as the ignition and cooling fan. Directly above the control panel are two gauges which display the compressor pressure of the turbo as well as the oil pressure for the cooling and lubricating oil.

The oil pump assembly

I used a power steering pump for the oil pump and a 12 volt motor to drive it. It worked well for a while, however, later in testing on the jet kart it failed and caused the main bearings of the turbo to be destroyed. More information can be found about the jet kart in its own section here on the site.

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