Paul, I was reading your article to day at a book store, didn't get
as much time as I, would've liked.
  I read where you said that an" RX 8 engine gets better fuel mileage
than Mazda's current four
  cylinder" are you sure about this?  I, don't recall Mazda making this
claim they do say the still
  under development 16x is more fuel efficient ,could you have been
thinking 16x when you said RX8 ?
Clifton

Yes.

Paul Lamar


I enjoyed reading your article Paul. A couple of things I found interesting
are; the series on accidents this month is related to engine failures. The
other is about buying a used engine and the potential pitfalls. Both also bode
well for the Wankel.

Dale Davies

Thanks Dale.
Yes I found the article on engine failures interesting. There really
is not much to go on in the NTSB reports as frequently the NTSB get
it wrong or find  inconclusive results. Experimental crashes are
not a high priority. I investigated a fatal rotary crash myself for
the FAA. It is my feeling internal alternative  engine failures are rarely
the cause of the crash. IMHO it is fuel, ignition and cooling.

About in that order. Before this newsletter started 12 years ago people
had no guidance on cooling the rotary. Invariably the cooling system was inadequate as one would look at the small physical size of the rotary and underestimate its cooling requirement. Cooling failures were common and many people gave up on the rotary.  Recently I am happy to say people are starting
to complain it is over cooled.

Probably the most difficult and subtle thing to design is the fuel system.
Very small pressures are involved and can cause  havoc on a fuel system.
A good example is pointing a fuel tank vent into the air stream can
empty a tank in minutes under the wrong circumstances. More people
need to becomes familiar with water manometers and start to use
them when trouble shooting fuel system problems. Certified aircraft builders
work the fuel system  out during the testing period and all subsequnet production aircraft have the exact same configuration.

Now for EFI things get complicated. Car electrical harnesses and systems  are designed and extensively tested and all subsequent production cars are identical as to configuration and exact location in the engine compartment and elsewhere.
Two adjacent wires can affect each other with induced currents and voltages.
This is expected to show up in testing. Thereby automotive EFI systems gain an excellent reputation for reliability. The RX8 coils situation is an example of how even this process can go wrong.

It is no wonder alternative engine aircraft have more crashes.
You can't just go to the airport and copy a Cessna fuel system, cooling system
or electrical system. Each alternative engine installation is unique.

The Internet is a huge step forward helping people get the information
they need to build a successful alternative engine experimental aircraft.

BTW Lamar's law of unintended consequences. "It always happens regardless
of the size of the change."

This applies in all walks of life. Marriage, economics, politics, programming,
mechanical design, drugs, electrical designs, chemistry, etc,, etc.. Everything!

Paul Lamar