Undestanding Tuned Pipes

It would be neat if someone with a pipe that is no longer useable would open it up and show us a picture of the internals.

1) Does a pipe need to be periodically cleaned or drained from accumulated oil between the chambers? During the off season?

2) Does the accumulation of oil significantly affect the C of G over time?

3) What is the difference in application and perfomance between a 3 chamber and 4 chamber pipe? Both can be used on a .40 size engine, right?

>It would be neat if someone with a pipe that is no longer
>useable would open it up and show us a picture of the
>internals.
>

I agree that it would be interesting, but there are a number of different pipes these days and the number is growing, so it would only be a representative sample.

>1) Does a pipe need to be periodically cleaned or drained
>from accumulated oil between the chambers? During the off
>season?

Not so much from oil, but from carbon. If you store the airplane nose down, the oil will run back into the engine. If you store it on the wheels (or tail down) it will drain onto the carpet.

The big problem, however, over time is carbon buildup in the pipe, and especially header. Most of the build up in the pipe will be in the intake opening which can get plugged up. The header gets the worst since it is the hottest and closest to the engine. A gun barrel cleaner can help here, and soaking the header in solvent (or anti freeze bath) can help clean it out. A lot is going to depend on the type of fuel used, how hard you hit the engine and how many flights you put on it. We haven't yet had the problem with the pin holes that some complain about or a charred pipe, but have had to clean the pipe and header several times.

>2) Does the accumulation of oil significantly affect the C
>of G over time?

Oil basically cleans itself out. But the carbon build-up doesn't. I suppose that could affect the center of gravity, but, if so, it is time to clean it out anyway.

>3) What is the difference in application and perfomance
>between a 3 chamber and 4 chamber pipe? Both can be used on
>a .40 size engine, right?

The length of the pipe is a factor of timing and rpm. Diamater of the pipe and opening size (inside and outside) will determine its suitability for whatever size engine. (Thus a 20 size and a 60 size engine of the same timing and running the same rpm would use the same length, but the 60 size pipe would need to be significantly larger in diameter. The number of chambers has nothing to do with engine size. It basically affects the quieting of the pipe and the broadness of the needle setting and rpm range.

>It would be neat if someone with a pipe that is no longer
>useable would open it up and show us a picture of the
>internals.

I was planning on doing that soon.

>
>1) Does a pipe need to be periodically cleaned or drained
>from accumulated oil between the chambers? During the off
>season?

No.
>2) Does the accumulation of oil significantly affect the C
>of G over time?

No, or at least not that I have noticed.

>3) What is the difference in application and perfomance
>between a 3 chamber and 4 chamber pipe? Both can be used on
>a .40 size engine, right?

If everything else is right, yes.