Hybrid test results.

[jimmy101]

I was filling from a 30 gallon compressor tank, which was room temp at the time. I let the chamber cool down to the point where it was just warm after each shot, which would have probably helped correct the cooling effect.

You might consider filling the test chamber then letting it sit for ten minutes of so, then fill it again. Just to make sure. Of course, this assumes you don't have any leaks.

[ALIHISGREAT]

i already commented on how the black gunk was because of incomplete combustion because his fuel was off... and then Fnord said it was probably some fumes from pipe dope that were saturating the chamber...

I doubt there is enough fumes in the chamber to leave noticeable residue. Besides, after the first shot or so the fumes should have all been burned, or flushed out of the chamber when the gun was flushed with fresh air.

yeah thats what Fnord said... he said the gunk was probably only from the first shot...

Based on your post, I think I figured this out.
The fumes from the pipe dope may have been igniting when I started testing, and causing the mix to be a little too rich. I imagine it would have burned off eventually, so I don't think it affected the final tests.

I'm fairly sure my fuel measurements were accurate (within 5-10%, anyway).

[jimmy101]

Hey _Fnord, what does the it sound like when you fire the chamber?

Dull "plunk"
Faint "plink"
Big bang
small bang
Doesn't make any sound that you can hear because you are 100 feet away when you fire it

My guess is that it makes little or no sound when fired.

[Fnord]

I couldn't hear much because I was too far away, but a little air seeps past the ball valve seals on ignition of higher mixes, so it makes a faint "squeak". I think it would probably make a faint plink if I could contain it completely.