OK, the dwell meter goes back in the drawer.
Thanks a bunch for the tips.
Dan Richardson
300L Family Heirloom
----- Original Message -----
Sent: Monday, November 27, 2006 5:09
PM
Subject: Re: IML: dual point distributor
questions
If your distributor has 4 lobes on the point cam, then its a double life,
if there's 8 then its a standard dual point. It doesn't matter either way,
pull the dist. and set each set of points VERY carefully to .018-.019
re-time the engine, throw you dwell meter in the bottom drawer of your
tool box, and DRIVE. The dwell will allways be in spec, if you set the points
as described. Ya'll have a nice day ,Dave
--------------
Original message -------------- From: therichardsonfamily@xxxxxxxxxxx
Does my dual point Mallory use one set of points to fire only 4
cylinders, and the other set for the other 4 cylinders? That would
double the point life, right? Or does one set fire all 8 cylinders,
and the other set fire all 8 - just alternating between each other? I
just don't get how the dual points work.
It almost seems that the Chysler dual point in the FSM, has both points
firing the same cylinder at the same time. That would be the reduction
in current flow through each, right? At the same time, allowing a
higher current flow on each fire. That set-up would also allow one set
to be insulated while you check the dwell on the other with the engine
running, right?
My Mallory looks as though one set opens when the other is
closed. That would not allow a dwell check with one set
insulated. Am I seeing that correctly? That is why I'm asking if
one set fires only 4 cylinders.
I assume the advantage in pulling the distributor when
setting the points, is that you can turn the shaft to be exactly on the
lobe, thus getting a more exact gap. I'll need to open them up a bit,
I'm at .014 while checking it installed. How many miles can I expect
to get out of a set of points?
As always, thanks for all the help,
Dan Richardson
300L Family Heirloom
--------------
Original message -------------- From: sosmi@xxxxxxxxxxx
The dual point distributor, was designed for HI-PO applications. The
Chrysler dual point, had 2 sets of points to handle high RPM, and reduce
the current through one set of points, they also ran higher spring
pressure to prevent point bounce at high RPM. Mallory came up with a
distributor called Double Life, it also had 2 sets of points, but they
fired alternately, and also" Doubling" point life. After many years, of
racing and performance tuning, I've found, the best thing is remove the
distributor, and adjust each point set to.016-.019 I prefer going on the
high side, because the point rubbing block wears, and you loose the spec.
quickly. Checking dwell, is a waste of time, because the point gap will
allways be between .016-.019 The other thing you could do, is convert to
electronic, with a pertronix kit.Ya'll have a nice day, Dave.
--------------
Original message -------------- From:
therichardsonfamily@xxxxxxxxxxx
Hello everyone:
I have a '67 440cid Imperial motor that has a Mallory Dual Point
(#ZC365HP) distributor on it.
Question #1 - exactly how does a dual point work? Does one
set of points deliver spark to 4 cylinders, and the other set to the
other 4? What is the high performance advantage to a dual
point?
#2 - I don't see a way to adjust the dwell when the car is running
- is that correct? I check the dwell, shut it off, pop the cap,
and guess at the adjustment?
#3 - I thought the FSM said to insulate one set of points while
checking the dwell on the other. If one set runs 4 cylinders, that
won't work out so well. How do I check & adjust the dwell on
this Mallory distributor? What am I missing here?
#4 - Do I set timing first, then the dwell? What are the
correct steps?
This one is right up Uncle Rodger or Dave's alley (two guys that
seem to have forgotten more than most of us will ever know about these
things)!!!
Thanks in advance,
Dan Richardson
300L Family
Heirloom
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