For What Its Worth
Distributer Installation in a V8
SBC
When
installing your engine, the distributer
goes in just after using a tool to pump up the oil. We used an old
modified distributer to turn the oil
pump shaft and pump up the oil pressure.
Pan, oil filter installed and oil added.
All the gears have been ground off the shaft
so it would not engage the cam. The top
was modified to take a speeder driver to turn it. We put
the tool in the distributor hole and crank the pump until we
have good
oil pressure. No dry starts/turn overs. Lifters pumped up etc. When
taking the tool out, don't get carried away yanking on it. It
should come out easily. Yanking could pull the pump shaft out of
the oil pump.
If
you don't have such
a tool, don't worry it's not critical to do it this way.
If you don't pump it up this way, I would
crank the engine with the ignition disengaged until you get oil
pressure before
you attempt to start it.
When putting in the
distributor it goes down twice, once to engage the gears, and once to engage
the pump. The pump only aligns every 180 degrees since it is a
simple notch. See picture of the notch.
Now the
distributor.
Old
fashioned points. Install the
points and condenser. Gap the
points. Install the rotor.
Don't forget the point lube on the cam that
actuates the points. Not too much.
HEI style, make sure the rotor and everything below is installed correctly.
If re-installing a previous used one, make sure the shaft run-out and
up-down free play are in spec. A wobbly distributor will drive
you crazy trying to figure out why it misses or wont fire.
Next make
sure #1
cylinder is at Top Dead Center or where you want the initial timimg to be. TDC
means at the top of the compression stroke. The crank turns
twice for every time the distributor turns once. Many
people put their finger on #1 and feel when the compression builds to
tell when it is the compression stroke. Not a little puff, that
could be the exhaust, but
when it tries to blow your finger into your ear that should be the
compression. Turn engine with
a wrench etc. by hand to align the crank to about 8 degrees before top
dead center.
Then look in your manual and see
where #1 wire is supposed to be on the distributor.
Put the cap on, Mark the #1 position on the
distributor base under the cap. Make it
easy to see, a marker, tape etc. Take cap off.
Put the round gasket
on the distributer. Make sure the area on the intake where
the gasket seats is clean and smooth.
Point the
rotor
to where # 1 wire goes then back it of about 25 degrees(Turning
Rotor CCLW). It will turn Forward/CLW when the gears engage
the Cam.
Put the
distributer in with the vacuum advance pointing between
the carb and valve cover on the passenger side.
As you push
down
it may hang on the cam Gear, turn the rotor back and forth a little
until you
feel it engage the cam gear.
This picture
shows a distributor going in, just as it begins to engage the cam gear.
It may not
go all
the way down after engaging the cam gear. It
may not be aligned with the oil pump rod.
If this is the case you will have to turn the crank until it
drops in
all the way, after engaging the oil pump rod correctly. (A helper may
be needed
to turn the crank or run the starter) The distributor
should be all the way down at this point.
Now put #1
back
on Top Dead Center of the compression stroke and then at the initial timing mark if you moved the crank.
Remember crank turns twice to distributor turning once.
Check that
the
rotor is pointing to the #1 wire location.
This picture shows the distributor down and the crank set to the initial
timing mark. The rotor points to the #1 plug mark. There are 14
gears on the distributor gear. If you are off you will be off by 25
degrees or more.
Check that the vacuum advance is in the
correct position. Assure you have enough room to turn
the distributor for timing adjustment without the vacuum advance hitting the
valve cover or other things.
Install the
clamp
and bolt, and snug down, lightly tighten.
Now move the
distributer a little until the points are closed. CLW or CCLW depends on how
close you are to begin with. On HEI move until the pick up is
aligned
point to point.
Then move the distributer CCLW until the points begin to open on
a point system. On an HEI CCLW Until the pickup is about 1/32" from
alignment, a very small amount of movement.
This
picture shows the pick up tabs on an HEI distributor.
Snug
down the clamp bolt to assure distributor doesn't move when started, but not too
tight. You need to do final adjustment after the car is running. The rotor should be pointing
at #1 wire position.
When it
comes
time to fire the engine, it should start without needing to move the
distributer. Using this install method I am consistently within 5
degrees of the desired timing mark.
Now put on cap wires, plugs etc. Cylinder numbers on a Small Block Chevy are
drivers side, front of the car to the back, 1,3,5,7 and passenger
side front to back is 2,4,6,8.
8 7
6 5
4 3
2 1
front of car
The firing order is, (MEMORIZE IT)
18436572. Looking in a book and checking if you have your plug
wires on right just doesn't work well. You need to be able to do
it from memory.
Distributor rotor turns in a CLW direction
when looking from the top. On the cap #8 wire is CLW of #1, #4
is CLW of #8 and so on.
Doing a distributor install the first time may take
two
or three tries to get the rotor and vacuum advance all pointing where
they
should go. A little experience and it is easy.
Now use the Timing light to do final adjustments and tighten the
distributor down.
Start the car,
without the vacuum advance hooked up and set the initial timing with a
timing light. Plug the vacuum line to prevent idle problems.
This should be below 800 RPM, to make sure the mechanical advance is not
functioning. You should be able to turn the distributor by hand, but
it should be snug enough to stay where you turn it to when setting it with a
timing light.
When done setting the timing, tighten the
distributor clamp down to prevent it from moving. Careful to not move
the distributor when tightening it down. Hook up the vacuum advance
line.
Often times
you will see TV or other mechanics turning the distributer drastically this way and
that to get the car to start. This is a sign of DIF, distributor
installation failure. It always gives me a good laugh to see them
do this.
Be careful
of some after market aluminum distributors. They may be good for
racing, but not for the street. The aluminum alloy used and lack
of anodizing may cause a lot of
aluminum corrosion INSIDE the Cap. Too much corrosion and things
go haywire. Anodizing is chemical conditioning against corrosio.
Here are some other
opinions on the subject from Steve's Nova Site.
Rewiring points to HEI.
Tune up notes
Happy Motoring,
VHubbard. Last Updated Sept 10, 2015
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