EFI Intake Conversion (1 of 2)

[Frederic Breitwieser]

Eric Aos wrote:

> Could we keep this on-list??? I'm starting on the same thing too. Just
> picked up some of that aluminum 'brazing' rod last night ($19.95 per
> pound at the local welding supply).

Well, I can give a quick dissertation of what I did if it helps you. 
I need
to do so anyway and take some pictures of the results for my website
anyway.

Recent Mopar Conversion:
I started off with a Edelbrock aluminum Streetmaster 383, which
coincidentally came on my 383 Mopar engine, which I am in the process
of
stroking to 431 cubes using a 440 crank and probably the 440YJ rods if
the
chevy rods don't look right.

Anyway, the manifold was sand blasted at a local place for $10,
brought
home, and marked for porting.  I marked the 383 heads as well as the
intake
using the gaskets and a black marker, then carefully ground the
openings on
the intake so there were no black lines left, fairly deep into the
runners
as to promote smooth flow throughout the runner.  I also got a little
carried away with porting the "deck" or the underside of the runners
stemming from the plenum area, but not too bad I hope.

Then, I measured the different stepped diameters of the injector base,
then
milled out an aluminum bung that is 2" long to match this.  I made it
longer
so I could clamp it at the top (I used a drill press, not a milling
machine)
and it could distort with no real issue, it doesn't need to be 2"
long.
After the different steps were created, I measured the outside
diameter of
the aluminum tubing that has been milled, then milled a same size hole
into
each runner perpendicular to the bottom of the manifold.  The runners
just
start to curve at this point towards the head.  Injecting at an angle
towards the valve probably would have been a better choice, however
with my
drill press, I couldn't get the manifold to "stay still" even with
clamps.
So, 90 degrees had to do.  Nothing wrong with this, just not
necessarily
optimum.

The holes in the intake were milled, the injector bosses pushed in,
then
TIG'd to the manifold.  I could have used alumaloy or duraweld like I
generally preach, but I wanted to practice my TIG welding and had
access to
a TIG machine.  7 of the 8 holes in the intake were tight, which is
good,
and one was a little loose, so I "propped" the injector bung up with a
piece
of wood and made a quick tack with the TIG, then welded the rest of
the way
around.

Now its grinder time again.  Anyway, I ground the injector bung so its
flush
with the bottom of the slightly curved intake runner by hand, doing so
for
each bung, then using a mill bit in the drill press I ground the top
of the
injector bungs to the right height, ensuring a good fit with the
injector on
the first one.  Once I got that just right, I locked the drill press
so it
couldn't drill any further, then repeated the other 7 bungs in this
mannor.
Push all eight injectors in, and they fit nice and tight.  Now, its
time to
make fuel rails.  I managed to find "scrap" 3/4"x3/4" aluminum bar
stock,
which I bored four holes in each, using the top of the injectors as a
guide.  I made two of these, one for each side, then attempted to bore
a
straight hole from one end to the other.  The milling bit I had
certainly
wasn't long enough, so I ended up sending the intake and the injectors
out
to a machine shop to have them make the fuel rails.  Bar stock was
free so
it wasn't a big deal anyway.

The bar stock will end up having each end of the length of stock
threaded,
for an AN fitting.  One will go to the fuel pump, one will go to the
regulator.  I plan to hose up the fuel rails in parallel, rather than
series, putting the regulator towards the front of the motor, and the
inlet
on the back.  All using nice AN fittings once I order them.

And that my friend is pretty much it.  I used the "Squirt Gun" article
in
one of the Mopar magazines as a guide, and by coincidence, my system
ended
up looking very much like their's, minus the fuel rail stock being
different.  It was a little time consuming, but was also a lot of fun
as
well.

Part 2 of 2 describes the "from scratch" method of making an intake
manifold
(at least for a Buick V6 <G>)

--

Frederic Breitwieser
Bridgeport CT 06606

1993 Supercharged Lincoln Continental
1989 HWMMV w/turbocharged 500cid Caddy
1975 Dodge D200 Club Cab soon to have 431 stroker + turbos
2000 (I hope) Buick GTP (Mid-Engined Sports Car)