Hey Paul,

  Would the oil injection hole just happen to be in the right spot, in
  relation to the rotor cycle phase, to serve as a good spot to install a
  fuel injector for direct injection of fuel into the combustion chamber?
    Is that spot subject to high temperatures?

  If the injector was located there could the fuel be injected close
  enough to the leading edge of the combustion chamber to mix well with
  the incoming air charge?  It wouldn't be good if all the fuel was
  concentrated at the trailing edge of the combustion chamber.

    Mark LaPierre

  Most direct injection attempts have shown no advantage.
  Best to put the injectors at the start of the runner so the
  fuel has time to evaporate.

  Perhaps with much higher pressure injectors on the order
  of 1000 psi.

  Those holes are  great for monitoring the actual  manifold pressure.
  They give a consistent number regardless of the typ of
  intake manifold used. If everybody used those holes
  it would be much easier to tune Tracy's EFI.

  Paul Lamar
  --

    The pictures of the direct injected Mazdas show the injector right on
top.
    Murry


True but nobody other than Mazda has driven one yet.
The picture on the web site is of a prototype.

We also don't know the timing or pressure of the injection.
Obviously the pressure in that chamber is rapidly increasing.

Everybody is welcome to try but you will need a lot
more pressure than 50 psi. Note there are no direct injection
gasoline engines on the market at this time as far as I know.
Porsche among many others have done a lot of research on the
subject spending millions.


Paul Lamar



Paul,
Audi, VW Chevrolet, and Ford all have DI gas engines now. There are probably
others, Hyundai probably, all report improved power and mileage. These are
true DI systems injecting near TDC. This requires a pump with around 18k
psi.
Bill Jepson



Are they really doing better than the average Honda or Toyota econo box?
http://www.fueleconomy.gov/feg/bestworst.shtml

I have removed the diesels and electrics from this chart.
Diesels don't pay off that much as the price of diesel fuel is higher
by as much as 15% to 20%. Electrics because they don't sell.
The stupid range extender Volt is a failure as I predicated.

Which of these are DFI?


http://www.ford.com/cars/fiesta/features/

The Fiesta is not. It is all about rolling resistance, transmission and aero drag. What I have been saying for years.

"When equipped with the SFE Package, the Fiesta SE hatch and sedan can get up to 40 hwy mpg.2 The SFE Package has cruise control, a spoiler and 15-inch steel wheels, plus aerodynamic features that help minimize air resistance such as side air deflectors, underbody shields and blockers on the lower grille."


Paul Lamar