Timing is just an adjustment which tells the engine when to send a spark to
each plug. The order is determined by the distributor. By adjusting the
point at which each spark plug fires, you can optimize power, economy and
emissions. "Advancing" the timing means causing the plug to begin firing
earlier. "Retarding" means the plug fires later.
You do this merely by loosening the distributor and rotating it - clockwise
to retard, counter-clockwise to advance on a GM inline 6.
Static timing is done by mechanical means with the engine not running. It is
usually accurate enough to get an engine running. Then you can use a timing
light to fine-tune the distributor position to the exact recommended factory
setting.
The distributor contains components (mechanical and vacuum advance) which
alter timing "on the fly" to suit varying conditions, but assuming these are
in good working order they don't require any adjustment.
Here is a link to a pretty good description of timing an engine, and why:
http://www.type2.com/library/electrip/timex.htm
Jack Halton
51 GMC 1/2 ton
Winter Park FL
----- Original Message -----
From: "tim" <lloydt@Colorado.EDU>
To: "Ole Truckers" <oletrucks@autox.team.net>
Sent: Tuesday, September 12, 2000 5:26 PM
Subject: Dummy's Guide to Timing (was Re: [oletrucks] Points -> electronic
conversion?)
> -----BEGIN PGP SIGNED MESSAGE-----
>
> Doesn't sound too bad. Now, assume I don't know anything about timing,
> and that I've never timed an engine. I have the shop manual for my truck,
> and (I don't have it with me at the moment) I'm pretty sure it covers the
> topic, but it assumes a basic knowledge of engine timing to begin with.
>
> Could someone maybe give a quick rundown of how to adjust the timing on a
> straight six, or perhaps point me in the direction of a tutorial of some
> kind? A list of needed tools would be helpful, too.
>
> Thanks in advance,
>
> On Tue, 12 Sep 2000, New Mexico Jim wrote:
> >
> > It was me who did that. I am very impressed with the way my truck
runs. I
> > switched over to R44S AC Delco plugs. The "S" is for extended gap. I run
them
> > with a .045" gap. I plan on running a cooler plug next time around, like
a
> > R42S. BTW, the "R" signifies a resistor plug. If you use Autolite plugs,
run a
> > number 85, I think it is. You may have to go to a smaller jet, because
more of
> > the gas gets burned and less tailpipe emissions and smoother running
engine.
> > It takes about an hour to do the swap taking your time. To make
things
> > easier, Make a mark somewhere number one plug so you can get the new
> > distrivutor close to where it should be to fire it up. Use a 10 gauge
wire
> > from the new coil to the ignition switch. Time it just like always. Set
the
> > octane selector to "zero" and set the steel ball to the timing mark and
maybe
> > a few more degrees advanced for mileage and power. Don't go too advanced
or
> > ping may happen and CO's will go way up. I mounted my coil on the head
by
> > number 5 spark plug. I used a bolt hole for the original coil mount.
> > The only thing I don't like about the set up is the vacuum advance
sticks
> > out at an angle and doesn't look as neat as it could. I wouldn't let
that stop
> > you from the swap, though. Redrilling the distributor shaft to shift the
drive
> > gear drift pin hole over one way to get the base to be parallel with the
> > block.
> > If you have any other questions, fire them off!
> >
> >
> > tim wrote:
> >
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> > >
> > > I remember some time in the not-too-distant past, some members of the
list
> > > were extolling the virtues of HEI distributors over the
> > > coil/rotor/points/etc system. I'm currently debating installing an
HEI
> > > system in my '54 1/2 ton (which has the I-6 235 and a 12V "standard"
> > > electrical system right now), but I wanted to ask the list -- is this
> > > something I can install in a weekend? A day? A few hours? Is there
> > > timing adjustment involved? I really have no idea what's involved.
> > >
> > > Thanks in advance,
> > >
> > > Tim Lloyd, omaha@tmbg.org
> > > "Power that comes from the barrel of a gun can only be effective for a
> > > short time." -The Dalai Lama
> > > "We choose to go to the moon...because that goal will serve to
organize
> > > and measure the best of our energies and skills, because that
challenge
> > > is one that we are willing to accept, one we are unwilling to
postpone,
> > > and one which we intend to win." -John F. Kennedy
> > > "Believe nothing, no matter where you read it, or who said it--even if
I
> > > have said it--unless it agrees with your own reason and your own
common
> > > sense." -Buddha
> > >
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> > >
> > > oletrucks is devoted to Chevy and GM trucks built between 1941 and
1959
> >
>
> Tim Lloyd, omaha@tmbg.org
> "Power that comes from the barrel of a gun can only be effective for a
> short time." -The Dalai Lama
> "We choose to go to the moon...because that goal will serve to organize
> and measure the best of our energies and skills, because that challenge
> is one that we are willing to accept, one we are unwilling to postpone,
> and one which we intend to win." -John F. Kennedy
> "Believe nothing, no matter where you read it, or who said it--even if I
> have said it--unless it agrees with your own reason and your own common
> sense." -Buddha
>
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> oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
>
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
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