Date: Tue, 26 Apr 2005 03:50:06 -0400
Reply-To: Jonathan Farrugia <jfarrugi@UMICH.EDU>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Jonathan Farrugia <jfarrugi@UMICH.EDU>
Subject: Re: advance mechanisms on digijet distributor?
In-Reply-To: <20050426070307.92862.qmail@web53506.mail.yahoo.com>
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Damon
i can't shed much light on your inquiry but i can tell you that recently
over on the Type 2 list a member posted curves for several of the air
cooled distributors. he took them to a shop that had a machine that can
test and print curves. if anyone knows i would be interested to know who
manufactures distributor testing machines and what kind of places have
them on hand.
for the data see section 1.14
http://www.ratwell.com/technical/FAQ/FAQContent.html
jonathan
On Tue, 26 Apr 2005, Damon Campbell wrote:
> Hello list,
>
> I am trying to understand the various mechanisms that
> control the timing on the early digijet. There is:
>
> * Static setting (just the twist of the distributor -
> sets the baseline for centrifugal and vacuum)
> * Centrifugal advance (rpm based advance... seems to
> kick in around 1600 rpm or so. Where does it max out
> at?)
> * Vacuum advance (one half of the vacuum canister)
> * Vacuum retard (the other half of the vacuum
> canister)
>
> Static and Centrifugal are pretty straight forward.
> The vacuum advance/retard is a little more confusing
> to me. First off, does the vacuum canister actually
> ever retard the timing? Secondly, the vacuum signal
> adjusts the timing for engine load (i.e. lugging up a
> hill at low rpms), right?
>
> Is idle the max advance condition (as far as vacuum
> goes), and then it just drops proportionately with a
> lower vacuum signal, or...? On a standard 1.9L wbx,
> how much of an effect of the timing does the vacuum
> signal have (5deg...50 deg)? I guess a more direct
> question is: at idle, if you unplug the vacuum line to
> the distributor (and plug it), how much does the
> timing change by? I'd be curious to hear with people
> with 2.1L wbxers with digijet FI have as a result,
> too.
>
> As you can tell, i am a bit unclear as to how the
> different aspects of the digijet distributor work
> together to proved a well-tuned timing map...
>
> Thanks for any insight,
> -Damon
>
> '84 Westy "The Van" w/2.3L WBX
> Vancouver, BC
>
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