Randy Rees wrote:
>
> Can someone explain how to set dwell? I can't find it in the Haynes
> manual an anywhere.
Assuming you have a contact points ignition system, dwell measures how
many degrees the points stay closed (i think -- or open). This is done
while the dizzy (and engine) is spinning.
This is the dynamic (and more accurate) method for setting the point
gap. To set the dwell you have to buy a tool called, coincidnetally, a
'dwell meter'. They are pretty cheap and gives you a hi/low range tach,
too, so you oughta have one. (The low range helps you sync your carbs.)
The dwell meter has two connectors. One goes to negative side of the
coil and the other to ground. Set the meter to 4-cyl and fire up the
car. There should be a reading on the meter near 60 degrees (this is
pretty much universal for 4-cyl cars).
If the dwell value isn't to spec, shut the car off and remove the
distributor cap and rotor. Hunt around in the distributor and you should
see your points held in with one screw. Note the screw has been pretty
much rounded out by now. That is called a DPO feature.
There also should be a notch in the points assembly that coincides with
a notch in the distributor plate. The distance between the notches is
about the width of a medium size screwdriver. Slightly loosen the
boogered-up screw so that the points plate will just rotate when you
twist a medium screwdriver in the notches.
Ground the high-tension lead for coil. Turn on the ignition and use a
remote starter switch to turn the motor. (The remote starter switch is
another tool that attaches to the 'starter' side of the starter solenoid
and a + battery source. In some cultures, the remote starter switch is
voice-driven and called "the SO.")
With the dwell meter still attached, turn the motor over with the
ignition on and the high-tension coil grounded to the car. As you twist
the screwdriver and move the points plate, you will see the relationship
of the points position, it's gap, and the dwell value. Fiddle with it
until the dwell value is to spec. Tighten the boogered screw and check
dwell again. You'll notice it changed a little. See if you care. Also,
if you want to, check your points gap with a feeler guage. It is now
'exactly' to spec according to the book so you can now get the proper
feel of 'drag' across the points with the feeler gauge of the correct
size.
Now review your work prior to buttoning averything back up.
See that little, tiny, wire with the insulation flaking off? The one
that goes from the side of the distributor to the points? When that wire
goes, your motor dies. You can replace the wire if you want. It usually
takes some soldering. That type of wire is hard to find so I just use
some small-gauge, stranded wire and have several loops between the
points and the distributor housing. Without some 'stretch' your advance
mechanism won't work.
See the other wire going to the little 'tin can'? That 'tin can' is your
condensor. See the points themselves? They should be flat across the
surface and at least 1/16 of material on each face. If there is a
peak/valley on the point faces, the condensor is bad.
If the surface is merely pitted, remove the points and drag some fine
sandpaper across the points and reinstall (i.e., start over).
Once you've gained these skills, you have acquired what is known as a
'lost art' as all the new cars have electronic ignition. With electronic
ignition, maintenance consists of driving the car until it dies
somewhere in the middle of nowhere, tow the car home or to a very
expensive garage and swap out all that computer shit for more computer
shit.
IMHO -- YMMV -- LOL
Bob Allen, Kansas City, '69CGT, '75TR6
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