The weights inside the distributer for the mechanical advance both work. You are correct that there is only 1 spring but it connects to the central shaft that the rotor is on. That one spring is all that is needed. You should see 20 degrees of mechanical advance if it is operating properly. The other 20 degrees is vacuum for a total advance of 40 (if everything is working right of course!). BTW the weights are slightly different but the one spring works both of them. Adding another spring will only delay the full mechanical advance. Generally you want it all in as fast as the motor can take it for maximum performance. David Teitelbaum vin 10757 --- In dmcnews@xxxxxxxxxxxxxxx, "content22207" <brobertson@...> wrote: > > Before I get flamed out of existence, let me clarify DeLorean spark > advance relative to its Volvo counterpart: > > The DeLorean ignition distributor has one centrifugal counterweight > disabled. Otherwise it appears to be identical to Volvo F Series > (mechanical advance spec's are one half Volvo's). > > To compensate, DeLo runs full manifold vacuum to the spark advance > diaphragm. Of course this makes the engine extremely difficult to > start and risks predetonation when the throttle plates are closed (max > vacuum), so they stick a microswitch under the throttle plate linkage > to operate a solenoid that cuts off vacuum spark advance when the > plates are closed. > > And of course base ignition time is advanced 3 degrees before Volvo. > > In contrast, Volvo runs ported vacuum (same port as the purge signal > to the charcoal canister) to the spark advance diaphragm. No > microswitch or solenoid. Not only is this a much cleaner and simpler > installation, but by virtue of having both counterweights active it > actually yields more spark advance at higher RPM's (minimum vacuum), > which is when you need it most. > > The whole DeLorean setup appears designed to maximize fuel burn at low > RPM's, such as stuck in California traffic, not yield better performance. > > As I understand it the DeLorean distributor does have its missing > counterwight inside -- it just isn't connected to the rotor hub. If > the missing spring were replaced it should perform like a Volvo > distributor (DeLo mechanical spec's are one half Volvo's). In such a > state vacuum advance could then be attached directly to one of the > throttle plate ports rather than the driver's intake rail. Otherwise, > owners are stuck with DMC's rather convoluted setup. > > FWIW: I'm running a fully functional distributor and find performance > to be quite invigorating. > > Bill Robertson > #5939 > To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/dmcnews/join (Yahoo! ID required) <*> To change settings via email: mailto:dmcnews-digest@xxxxxxxxxxxxxxx mailto:dmcnews-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/