Why Build a Logger?

It has come to my attention that some of the people think that the reason for my efforts in developing the vibration data logger is to "prove if the Corvair conversion is any good"

I am a FAA licensed power plant mechanic as well as an electrical engineer. I have been instrumenting engines and ground vehicles for the past 15 years and I have looked at data from all kinds of engines from all over the world including aircraft engines modified for ground power units. I will tell you this. The Corvair engine modified per Williams’s specifications, is a rugged, smooth running engine and is as robust as any other that I have seen. I selected the Corvair conversion after much study and analysis and I frankly think that, if an engine is converted to Williams’s specification, it will perform better and will last longer than an equivalent the O-200 for a lot less money.

That being said, why then am I building this logger? Well there are three reasons as follows:

1) This is experimental aviation and I did not build a "stock" William conversion nor did Mark Langford and some of the other builders who are on the test list. Some are Big Boy conversions; some have extended prop hubs and other "enhancements/modifications" from the tried and proven 2700 design. The data logger will show us some information about the impact of the modifications from the "stock" build.

2) No two builds or builders are exactly the same, however, you can determine through a statistical analysis what a normally operating engine and propeller combination should look like The system can provide a builder with a measure of confidence that at least his/her build falls within the norm of the "stock" conversion or if he/she is an experimenter, what is the impact of their modifications.

3) Future testing and enhancements. For those who really understand that this is experimental aviation, the final reason should be clear. I plan to use a turbo charger on my motor due to the altitude from which I must fly. I also want to look at developing a fuel injection system for the engine. At some point in time, someone has to experiment with these enhancements and collect data on these modifications.

These are my reasons for this data logger. It is my understanding that the builders who have agreed to have their motors instrumented are not out to prove if the conversion is any good. For most of us, that particular question was settled long ago before we built our motors. What we want to understand is the dynamics of various installations and deviations from the standard stock build.

You may feel free to contact me at any time on this subject, and I will be happy to discuss any issues relating to this subject. Just email me at (johnkearney @ att.net) remember to take out spaces.

To those who are "waiting to find out is the conversion is any good" do not wait for this data logger project to complete because it never will be. For as long as we continue to experiment with the engine, I hope that we will be taking data to better understand the implications of our "modifications" from the stock conversion.