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Final Preparation for Engine Run

 Prepping for first engine Run

We still have quite a few items on the list that we need to accomplish before we can begin the flight test with the Polini 250 engine. One of those items is to incorporate a new nose skid/wheel. In this picture here were machining out one of the nose skid mounting adapters that takes the place of both the existing nose skid and the tow hook mount on the lower keel.

Side one is completed and ready for the other side to be machined.

The mounting brackets for the new nose skid, both top and bottom sides. We will still need to drill a hole through the apex for the mounting of the nose skid.

We received a waterproof connector for the ignition switch module that will allow us to separate the engine from the instrument panel by simply unplugging the connector. In this picture Jason is installing the connector on to the engine side of the wiring harness.

In addition to the crimp connectors we also like to solder them for more positive connection.

Jason is removing the exhaust system so that we may install a EGT probe.

Although in EGT is not necessary we felt that the data needed to be collected during the test flight. In order for us to be able to better support this engine. this required that we machine a fitting to be welded to the exhaust system that would adapt to the existing EGT probe.

This machined fitting was welded to the exhaust manifold in the most convenient spot that we could locate. We realize that this data will not be particularly valid because of the way that we are choosing to install the system however it will give us great reference data in relationship to other data. Once we are able to analyze the spark plugs we will be able to correlate the EGT readings with the spark plug readings and build a table that corresponds with the carburetor settings throughout each one of the carburetor ranges.

We are using a typical Bayonet style adapter that will allow us to insert the probe to a very specific depth.

Because we are very concerned about not modifying the engine from its stock configuration we would like the probe to be inserted just far enough to get a reading but not so far as to disrupt the flow of exhaust gases. You can see that we have just the tip of the EGT probe inserted into the inside of the exhaust manifold.

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About Brian Carpenter (255 Articles)
CEO Rainbow Aviation / Adventure Aircraft

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