[T2] Vacuum advance

[Dennis Gentry]

What kind of bus? (I guess it must be '71 or earlier with a smaller engine,
because I think '72 and later all have vacuum advances).  Manual or
automatic transmission?

I'm guessing that by "electronic ignition" you mean something like a
Pertronix conversion or entire new distributor?  (I like those, by the way.)

I would stick with centrifugal advance if that's what came stock --
centrifugal and vacuum advance produce different advance curves.  But most
of the buses I have worked on came with a vacuum advance.

Is it that you can't find a vacuum inlet on the carburetor to connect to
the distributor's advance unit?

Again, it depends on the year of the bus (and type of transmission), but my
'72 manual, for example, has a 4th gear vacuum advance cutoff switch which
interrupts the vacuum once you're in 4th gear.  If you are really switching
to vacuum advance from factory centrifugal, you'd probably want something
like that unless you are willing to leave the timing less advanced than is
optimal.

Or if this is just to get the bus 10 miles to the garage, you can just
leave the vacuum advance disconnected and get by with the mild
centrifugal-only advance that most "vacuum advance" distributors have (and
you'll cut 20% or so off your maximum power.)

OK, I'll pipe down until I find out more about your bus.

Best,
Dennis
P.S.
https://www.wolfsburgwest.com/wolfsburg_new/electrical/electrical_common/distributors.cfm
and https://www.summitracing.com/parts/pnx-d186504/overview/ have some
examples of what I'm talking about.

On Sat, Oct 8, 2016 at 3:56 PM, Bob Pratt <ka1dza at verizon.net> wrote:

> Hi all.
> I finally found someone who will help me with the wiring on the bus.
> Now I'm working on getting the engine started to drive 10 miles to the
> garage.
> A friend gave me a distributor with an electronic ignition and vacuum
> advance.
> My bus does not have vacuum advance. Is it difficult to change over? Do I
> need a different carburetor?
> Thanks again for the group's collective knowledge.
>
> Bob
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