Jerry Hey wrote:
Paul, in the attached drawing, the part of the injector that
the
clamp
fastens to is longer than my "stock" Mazda injectors. Is the
one
you
drew also a Mazda injector? Further, what injector do you
recommend
for my application? If I build the clamp as shown, it
will
be
taped for fuel line hook up similar to what Klaus did (no hard
fuel
rail). I assume I need a regulator before the return to the
tank
These injectors will be aimed right into the bell mouths, but
how
far
from the bell mouths should they be? There is also the issue
of
nailing down the clamp inside the box. Clearly I need help
with
the
final design. Jerry
p.s. can you recommend a text on fuel injection?
The injector in your picture has something around the feed
barb.
Perhaps
it is a seal of some sort. Mine do not have that part and the
barb
is 5/8th of an inch long. Try removing it. I also remove the
plastic
on the injection end as well. Here is a picture of an injector
when
that stuff removed.
Paul Lamar
Paul, can you design the clamp so that it holds the injectors
vertically? That will cut down on stuff blocking the bell
mouth.
I
would like the clamp rotated 180 degrees so that I can drill and
tap
the base to screw the clamp down to the plenum floor. Thanks,
Jerry
Something like this?
Paul Lamar
Paul, the way I have been imagining this, the injectors are
fully
inside the plenum. The plenum box size is not yet determined but
something like 10 inches square 4 inches deep is entirely
possible.
Jerry
Sounds like you have a death wish :) You don't want the wiring
inside that box. That box by design has a stochimetric(s?) fuel air
mixture which
will make a great big boom waiting for a source of ignition.
My insurance company that handles my liability insurance will
not let me design something like that. Just kidding all you
ambulance chasers out there. I have no deep pocket insurance
company.
This is an easier, cleaner and easier to maintain. The injectors
just fit in a hole in the outer wall of the plenum. The fuel rail
block holds them in place. The wiring is easy to get to.
The plenum is made from a chunk of four inch square alloy
extrusion.
Simple and cheap to make.
Paul Lamar
I believe that last spring I originally asked about aiming the
injectors directly into the bell mouths as opposed to installing
them
in the runners and only then learned that it had been done before.
I
think a drawing was published that showed the injectors inside the
plenum. I then asked about the danger of explosion and was
reassured
that the current was not enough to create a spark. Maybe I am
remembering it all wrong. I'll be interested in reading further
responses about this in the next few days.
Anyway, no I do not want to create a bomb. And I do like your
design
for mounting the injectors. That is what I was after. The
remaining
issues are air filter and ram air. If you finish the design for
me,
I will build the first edition before the end of the year. Does
Rhino
have the capability to produce a standard 3 view with dimensions?
Thanks, Jerry
This I think this what you saw. The driver is clothed in a fire suit
and he can slam on
the brakes and jump out :)
Sure on the 2D drawing. I can also send an IGES. What drawing program
are you using again? The tricky part is the fuel rail clamping
block.
Paul Lamar
I use Vector Works. I can open autocad files (DXF DWG) and IGES.
Measured 2D drawings are useful to build from. But for understanding,
nothing can beat Rhino renderings. Jerry
OK Jerry. ACAD it is.
Paul Lamar
Paul, here is a mock up of the proposed system with 22 inch runners,
butterfly to bell mouth. It can be fitted under my cowl but it
certainly will not fit under all cowls. Can we lower the height by
using two 90ºs instead of the 180º? Bend radius of the 180 is 3
inches. Bend radius of the 90º is 2 inches. Instead of butt welding
the 90ºs which might cause roughness inside, a sleeve could slipped
over the joint and then welded. Or I can practice my butt welding on
this material until I get dialed in to the point where the interior
walls remain smooth. Or we can join the two pieces with a rubber hose
as we are doing elsewhere in the runner. It is important to me to
be able to fit this system under any cowl. Jerry
Three inch centerline is about the best you can do in 3 inch thin wall tubing
90 or 180 degree bends.
You could tilt the tubes to lower the height. There are some other ideas
I will work on such as a sharper radius 180 degree bend casting typically
used in turbo charger plumbing.
Paul Lamar
Go to a 3 inch high by 4 inch wide plenum and rotate the tubes back
about 40 degrees. You will need to grind here and there on the front
housing (car) and maybe dimple a tube here and there.
Exact angle by trial an error. Also shorten the plenum to about 8.5 inches.
Paul Lamar
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