Distributor Intallation Tip

[jlandry@domain.elided (John A. Landry)]

Me again!

For those of you who have an MSD Adjustable Timing Unit, you might
appreciate this...

Last night I installed a Prestolite distributor I rebuilt into my 76
Traveler.  I set the engine on TDC of the compression stroke for the #8
cylinder, inserted the distributor with the rotor pointed to a cap terminal
which was connected to the #8 cylinder.  I then tried to start the engine.

I cranked and cranked and the engine would just barely catch but wouldn't
run.  In fiddling with the distributor (advancing and retarding), I finally
got the engine running, but just barely.  I verified and reverified that
the rotor was pointed correctly and that the plugs were connected
correctly.  Once I was able to get the engine running well enough to jump
out and use a timing light, I found the timing extremely retarded... like
maybe 20 degrees or so.

What I had forgotten was the MSD Adjustable Timing Unit!

No device can electronically advance the spark after the trigger signal has
already been produced.  There's no way a device can go back and make
something occur before it happens!  The MSD Adjustable Timing Unit
functions by actually retarding the ignition advance about 15 degrees.
Upon installation of the unit, the ignition advance is then returned to the
normal setting.  This gives the driver the ability to *reduce* the amount
of retard the Adjustable Timing Unit is producing from no reduction (which
gives approximately 15 degrees of advance because the timing was advanced
during installation) to full retard which returns the timing to the
standard setting.  Sounds confusing, but once installed the dial turned by
the driver is clearly marked "advance" so *how* it works doesn't matter...
it just does.

So with the Adjustable Timing Unit installed providing 15 degrees of timing
retard, I had forgotten about this and was beside myself trying to figure
out why everything appeared so screwed up!  I was *almost* ready to yank
the Prestolite distributor back out thinking there was something wrong with
it.

Consider yourself warned.  You don't have an excuse now to frustrate
yourself like I did.  <grin>

Take care,

John
------------------------------------------------------------------------
jlandry@domain.elided             |
Conservative Libertarian        |  Scout(R) the America others pass by
Life Member of the NRA          | in the Scout Traveler escape-machine.
WA Arms Collectors              |
Commercial Helicopter - Inst.   | 1976 Scout II Traveler "Patriot" model
http://www.halcyon.com/jlandry/ |     1977 Scout II Traveler (Parts)