Manifold pressure fluctuation

[Shadetree]

Here is the deal. Lycoming 0360, Dynon 180, CS Hartzel in a RV8A that I purchased in July. I have been searching this forum and see that a orfice fitting or a cigarette filter will calm down the MP readings. I pulled the cowling for an oil change today and decided to check the line going to the MAP sensor. I found both a orfice and what looked like a fiberglass filter in the line next to the MAP sensor. I still have some fluctuations with these installed.
Here is my question.
Should the orfice be situated close to the cylinder instead of next to the MAP sensor to get the erratic readings calmed down or is there something else I should look for?
Thanks for any pointers.

[RVDan]

The orfice fitting should be the first fitting off the intake. It is intended to ensure that enigine operation is minimally affected if the line or sensor fails (leaks).

If there is a dampener to settle down short term fluctuations, it would work best if installed near the engine. That would give the line volume some ability to provide damping.

[Shadetree]

Originally Posted by RVDan

The orfice fitting should be the first fitting off the intake. It is intended to ensure that enigine operation is minimally affected if the line or sensor fails (leaks).

If there is a dampener to settle down short term fluctuations, it would work best if installed near the engine. That would give the line volume some ability to provide damping.

Thanks for the reply. I found a thread that there are some folks that buy a fitting from McMaster Carr that will screw into the intake. I may give that a try.

[N941WR]

An easy way to put in a dampener is to take AN426AD-4 rivet, the length doesn't matter and drill the smallest hole you can through the middle of it.

(You are dealing with pressure, not volume, and the small hole will work just fine.)

Then put that in the fitting on the cylinder head, the AN hose fitting will hold it in place and keep it from moving around.