cat sucking engine... and tales of the sea (wob?)

[john <j.s.smith@xxxxxxxxxxxx>]

>Subject: cat sucking engine...

>someone wrote:

>If your engine is sucking stuff out of the cat, then you have a much
>large issue than efficiency, or power. You should be shopping for a new
>engine because yours is running backwards.
>Nothing in the exhaust will ever be sucked anywhere, let alone upstream
>to the engine. It would go out the tailpipe, away from the engine.

>*********  This "absolute" struck me as odd, but I'm sure it's based on
>experience/lack of.  Never say never.

>The truly experienced know that they don't know everything.  How about a
>backfire through the intake manifold *and* carburetor?  This is not the
>correct "direction" for air/fuel travel, yet it can happen under some
>circumstances....right?

>I've only been interested in and working on cars for about 20 years, and own
>a business related to automobiles, so I suspect there are many things I
>haven't seen, and I know there are things I don't understand.  We all know
>that exhaust flows out through the exhaust pipe.  We also know that there
>are many different things at work. Outside of helping us to understanding
>volumetric efficiency-the internal combustion engine is far more complex
>than a simple air pump, to which it is sometimes compared.

>My $.02

>Rod Birch

Must say I agree with Rod et al. The more one sees, the more there seems
to be discovered! Ok in theory the engine sucks in air at one end and
blows it out the other - but it's not a perfect device. I doesn't seem
difficult to believe that maybe backpressure, turbulence (or something
else) could cause this mysterious effect. And anyway, some folk have
reported seeing bits of cat in the engine! Just because we can't (yet)
explain it doesn't mean it can't happen.  An now to make the point a WOB
tale of the sea :-)

Ancient mariners (from years ago - not very old mariners :-) ) told of
throwing a (weighted) corked bottle over the side which was attachted to
a long string. When they pulled it in again, the bottle was found to be
full of water... and the cork still in place. [cue strange erie watery
music].  Ok, this is strange  - if not "impossible" right. Anyway, a few
years ago this thing was tried with a camera fixed to the bottle. It was
amazing to see what happeded. At a considerable depth, the outside water
pressure forced the cork into the bottle and sea water flooded in
filling the bottle and expelling most of the air. The cork still tried
to float upwards and wedged again into the neck of the bottle. When the
bottle was pulled up, the decreasing sea pressure pulled the cork back
into place and sealed the bottle again!

Sorry if you've heard this before - I still think it's amazing though.
- -John

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