James M. Knox wrote:
: A much better solution is to produce the same power but well LOP
: (assuming your engine is balanced for it). The pressure wave integrates
: to the same effective area under the curve, but the peak is not only
: lower but less sharp in form. At the same time the fuel usage is at
: maximum efficiency, and the exhaust is cleanest - not only from a
: pollution standpoint, but also from the point of reducing any chance of
: carbon monoxide risks.

I feel obligated to throw in a tidbit here. Having worked on
hybrid electric vehicles in a former life, I've run into some interesting
engineering tradeoffs in cars. While it's true that running LOP reduces
CO emissions, it *increases* NOx emissions. With the higher EGTs and
excess O2 running LOP, more of the O2 react with N2 in the mixture to
create NOx's. For cars, the EPA says that's bad too. So, fuel injected,
O2-sensored cars with catalytic converters have a balancing act between
running at peak efficiency, and having to scrub out NOx, or running richer
and burning out excess HC's.

Fortunately, we don't have to put cats on our planes yet, and NOx
is less deadly than CO in flight.

: Back to the first two points... anyone who tunes race engines for a
: living or some such, want to weight in with more information. Wouldn't
: be the first time I'm all wet. G

Usually the racer-performance types are all about the horsepower,
so talking efficiency is generally useless. They run whatever mixture
will maximize HP, nevermind the eye-tearingly rich mixture the exhaust
leaves behind!

-Cory

--
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* The prime directive of Linux: *
* - learn what you don't know, *
* - teach what you do. *
* (Just my 20 USm$) *
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