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Chapter 3 PUTTING
IT ALL TOGETHER Three
Easy pieces* The
Manifolds My goal, like the American Indian, was to use as many
parts as possible from the buffalo (or in this case the Champion motor) being
butchered. This would assure that anyone could do the same thing. Too often
in articles in car magazines you will read along saying "I can do
that" to yourself until you come up against the brick wall of "now
use factory tool J-619712" or "we then went over to
Bio-Cryo-Techno-Wiz-Bang Automotive on Labrea in Los Angeles" to have a
prototype hyphenization carbueration coagulator installed (for free), at
which time you swear and stop reading....NO! I was determined to do this with
only a wire feed welder, the stock intake/exhaust manifold, a grinder, a
drill and a hacksaw. I first hacked,drilled, chiseled and ground on the
intake/exhaust manifold just above the level of the set-screw in the side of
the exhaust manifold. The cut was made just below the "floor" of
the intake which normally was getting heated by exhaust gases. After getting
it off I was able to work on it as two separate systems. Exhaust/Turbo
flange: After grinding the top flat, I bent a _ inch
strap in roughly a square shape, grinding parts so that it would slip over
the square cross section at the "cut off" point where the two
manifolds connect. I then made a flange that would bolt to the exhaust intake
of the turbo using studs. I am told that bolts used here should not really be
high grade due to the expanding and contracting going on. I made a copper
gasket of sheet copper to echo the shape of the flange. I made a plate of 1/8
inch steel to cover the exhaust header flange and remove the heat riser
valve, covering that too. These two parts of the exhaust manifold might be
used later as an exhaust bypass. The turbo flange needs to be oriented so
that the turbo is in the appropriate position for the exhaust and for the
induction system. The oil inlet should be high (I made mine directly on top)
with the oil outlet low for best drainage (in my case, into the side of the
oil pan above the oil level). In my case, the exhaust will be to the bow and
the induction will be to the stern. The
Exhaust/Turbo mounting separated
manifolds the
turbo flange plate before drilling out
cutting
out the turbo flange plate mocking
up the turbo manifold the
raw manifold before cutting above setscrew trying
on the flange plate the
raw flange plate
exhaust
manifold attached to turbo with outlet pipe welded on Exhaust
outlet/bypass Exhaust outlet/gate
modification Exhaust outlet/gate
modification also Exhaust outlet/gate
modification too
Exhaust
outlet/gate modification done* Exhaust pipe
cover* Outlet piece done
Question: Should I
restrict the volume of my exhaust manifold further with a "filler"
attached to the cover
plate? The
Intake Manifold: To make this, I needed three thick
flanges to coincide with the siamese intake ports. I cut the flanges off the
old cast iron manifolds and ground them flat. To make room for the turbo to
sit roughly where the carb used to be, I had to have runners that came 90
degrees pretty quickly just before they entered into the motor. After a lot
of thinking, I settled on fashioning these angles by careful cutting of some
square tubing. The flanges weld on the side of the tubing. The runners
need to be long enough to rise (when added to the height of the 2 x 4 x 18
inch plenum) above the height of the head studs, allowing the head to be put
on the motor and taken off without taking the whole thing apart. I fretted
over the plenum. It is big with not especially a streamlined shape. A lot is
made of air flow and gas puddling in intake manifolds, but I think that some
of it becomes less important when one has a few atmospheres of positive
pressure. I did hang a piece of cut angle iron over the middle intake runner
to "disperse" the gases slightly (theoretically keeping the center
two cylinders from running relatively richer than the others). I welded nuts
over two holes I drilled in the manifold (as location for sensors or
injectors later). Finally I had both pieces sandblasted then painted them
with high temperature (1500 degree) aluminum paint. The whole unit bolted
together makes a rather compact package. How much gating is necessary remains
to be seen. Quick throttle response is important to me. Quick spool up from
the small turbo and short exhaust set up is expected. The long-legged intake
manifold may hurt the spool up (I may inject compressed air saved from the
waste gate to help this problem, but that's another
story.............). The
Intake Manifold intake
flanges and completed runners before joining
another
view of flanges and runners before joining intake
manifold before sandblasting and paint
also
intake manifold before sandblasting and paint also
another view of flanges and runners before joining
welding
runners to plenum intake
flanges welded to runners
mocking
up the plenum to intake runners checking measurements
for runner length with an Edmunds high compression head in place
runners in place to
check positioning of plenum to clear head Intake done*
Question:
1)Should
I further restrict the volume of the plenum with a
filler?
2) Do I really need the "disperser" beneath the carb? I'm told that the disperser is a good idea, and that
optimally, I should have made the manifold a rounded cross-section with some
length beyond the end runners. The
Carb Used:
One probably doesn't need a huge carb for this. I bought four at $5.00 to
$40.00 each and had two original "WE " Carters, one of which I have
re-built. Besides the Carters, I have a Holley 1904 single
"economy" carb, a 60's Carter dual carb, a later 60's Holley dual
carb and a Weber dual carb from a BMW 2002. The intake manifold was built
with a removable top plate which will easily allow me to try each carb without
major surgery. The carb must be "pressurizable" or must be entirely
enclosed in a box (more necessary at higher boosts). To do this requires
modifying the carb so that all the "holes" (like at throttle
shafts) to the outside or through the float chamber are at a pressure
"against" outward egress of fuel/mixture. This is sometimes a
non-issue at boost less than 10 lbs and with some carbs. I added air passages
to the throttle shaft of a "WE" carb to achieve air bearings/seals
with air pressure provided from above the ventures. On both the WE and the
Holley I filled the floats with polyurethane foam (and epoxied the holes I
drilled shut) to keep them from collapsing under pressure. My
first choice will be the 1904 Holley. It is from a 196 cubic inch Scout slant
4 cylinder motor. It is simple and parts should be easy to get. It is a
little bigger in capacity than the original carburetor. It was also used on
early 60's Ford six cylinder motors up to about 225 cubic inches. The Holley
carburetor was new in the box for $40.00 and useless to anyone else. The WE
carburetor is just big enough for my plans but difficult to modify jets. It
seems to have a needle arrangement. I need to explore this more. The Carter
and Holley dual carbs are possible but need restoration and are overall more
complex. The Weber is sexy, but maybe too small - again I need to study it
more. Besides filling the Holley float with foam, I replaced the float
chamber breather hole with a nipple which could be tubed up to the compressor
outlet. I'm told that the single Holley may be
marginal and that a better performance choice might be a carb between 350 and
600 cfm. My used Holley two-barrel turns out to be from a 73' Dodge
truck with either a 360" or 400" motor. It is called a "6575"
and is 330 cfm. I'll get this ready in reserve, and get running with
the single carb Holley for now. The Carb
situation crusty WE carb
WE blown-apart
before foaming
the WE float
after foaming
the WE float Holley 1904 gas line
side Holley 1904 top side
Holley 1904 other
side Holley 1904 bottom side
Weber carb
Holley 2 barrel 6575 330 cfm 1 2 3
Carter 2 barrel 1 2 Question:
1) Is
the float chamber connection necessary or could it just be blocked
off? 2) Am I kidding myself in thinking that the Holley 1904 is
adequate? See above.Any hints on how to
rejet it? The
Fuel pump:
My first thought was to use an electric pump, but came across some info in an
old book about pressurizing the "other" side of the diaphragm of a
mechanical pump with a connection off the compresser outlet. I then saw this
mentioned in a recent "Real Safaris". I have determined that it is
feasable with the Stude mechanical pump and fabricated a nipple for the
connection at the site of the breather hole. I may need to install an
auxiliary pump activated by a pressure switch to provide enough pressure to
overcome the boost pressure in the float-bowl. Is there a common
pressure switch that I could find? (ie: brake switch?) Further
air "processing": You may note from the pictures
that there is a 3 inch piece of tube just above the carb. This section is in
place to give some "wiggle" room should I change carbs, allow a
place to inject air or water into the system to decrease lag or prevent
detonation. It will initially act as an air "straightener".
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