Paul,

  I was looking at the web site at Mark's P Port installation specifically
  the plenum.  What is the function of the plenum?  Does it trade high
  speed air for pressure? The web site says it is to contain the vapor
  cloud that was apparent on the U tube dyno run.  The web page states
  that it is not needed if injection is used.  I just wanted to get a
  clarification on it.  How big should it be?  Is it volume or a specific
  size?  I have space constraints and may use part of the lower cowl
  as a surface for the plenum. I would like to place injectors in the
  tubes rather than in the plenum.  If the hot wire MAF is mounted on
  ther entrance to the plenum does this pose a potential hazard?
  What are the dimensions for the tooth wheel for the 555 EFI design.
  Thanks for any help.

  Joe Berki
  13b P Port


  It keeps the vapor cloud from floating away :)
  The web site is wrong. What web site? Who's web site?
  As large as possible.
  The hot wire mass airflow sensor does not present a problem at
  the entrance to the plenum. It is really just a warm wire.

  The shape of the toothed wheel depends on the ignition type.
  Probably 2 teeth 180 degrees out.
  It can be 2 inches or 8 inches in diameter. It matter not
  as long as tooth is pointed.

  Paul Lamar


Paul,

I went back an looked at your website to make sure I had said something
wrong, but under the section for intakes and slide throttles the bullet
that
calls up the Youtube video of the cloud states that it is'nt a problem
with
fuel injection.  I think it is as Mark has a plenum on his Mustang.  The
more I look at my engine compatment the more ideas come up.  I think I
will
mock up a plenum divided into two parts.  The forward section will be
exposed to the small scoop that points forward under the strake and will
contain the MAF sensor with a conical air cleaner.  It will dump into the
aft section where the 22" runners from the rotor housings will end and
perhaps the best way to mount the injectos is to place them in the box
pointing at the ends of the runners and use velocity stack type ends.
Plenum wil be aluminum.

Ordered a stainless exhaust header flange from Mazdatrix today.  The
entire
exhaust system next to the engine will have a heat shield.  Thanks for any
help.  Looking forward to seeing the data off of Mark's engine.

Joe Berki
Limo EZ
2nd gen P Port

OK Joe. I see it. Thanks I'll fix it. I don't want to give that
impression.
Although it might not be a problem with the injectors mounted
down near the port there is no point in taking chances.

Paul Lamar
--

Joe,

If you already haven't you might go to Racing Beat's website and look
at the neat air intake,filter and MAF sensor unit they already
engineered. It might save you some time and $$,

Doug in Japan


I stood next to Mark's p-port engine while it was running with the top
off the plenum and there was not that much fuel vapor coming out. Of
course
the prop load on this engine is minimal so things may change
when he gets a real prop on there :)

Paul Lamar

Paul,
The carb version will always show a big fuel cloud as the reverse air flow
is drawing fuel out of the venturies on it's way out...
The reverse air flow cannot draw fuel out of the injectors, so the cloud is
far less.
Larry

That is probably the main problem. The mist has been seen on fuel injector
systems as well. Take no unnecessary chances :)

Paul Lamar