"The distributor doesn't care; engine tune does. Ported spark reduces emissions at idle, slightly. It can, for some setups, cause the engine to run hot at low speeds (late timing so all the fuel_air energy goes out the exhaust). If it's not doing anything bad now, just leave it." My 304 Spirit didn't like manifold vacuum at idle - had a little misfire. Using ported vacuum for idle smoothed it out. 'Course I have a bit more initial advance than stock also. Ken Quoting tom jennings <tomj@xxxxxxx>: > > cc'ing the list cuz it looks more broadly applicable... I hope you don't > mind... > > > > ======== Ok, but how about the distributor? Does it just "drop in", or do > I > > have to change the gear on it, shim it, etc. ? > > Any AMC six distributor drops in -- you do NOT use the Ford > distributor... for the AMC six there were only these choices up til > the 4.0... that change-gear business is to adapt a Chevrolet distrib > to an AMC engine. Bu > > * points distributor 1964-early 70's (small cap, the one you know and love) > * prest-no-lite distributor, early 70's > * duraspark mid-70's on > > They all fit in the hole and clamp and are mechanically > interchangable. I just don't know anything about AMC engines after 83 > or so, others here do. > > > > -========= What distributor would I need for the Pertronix, > > Any 232/258 AMC six POINTS distributor. No one want's em! But if you > have to go seek out a distributor, box and all that, might as well go > Duraspark. (I originally thought yu had a points distrib, that's wy I > suggested the Pertronix.) > > > > ======= So get the Duraspark distributor coil, or are you talking about > > another type? > > The EASIEST thing to do for you I think is to get an AMC six Duraspark > distributor (AMC only), a duraspark box (Ford or AMC, same part), and > the connectors from a Ford or AMC donor junkyard car. AND use whatever > coil is in there now. The Duraspark system will drive any reasonable > coil, including dead stock all years. If your coil now has a resistor, > continue to use it. > > > > ===== Another reason I want to convert the old Prestolite to Presto! GONE. > > GOOD IDEA! > > > One question on timing - some cars base the timing on ported vacuum, > others > > on direct - looks like this '76 Hornet went ported. Do the Duraspark > engines > > base it on Ported, too, or would I need to go back to full engine vac? > > The distributor doesn't care; engine tune does. Ported spark reduces > emissions at idle, slightly. It can, for some setups, cause the engine > to run hot at low speeds (late timing so all the fuel_air energy goes > out the exhaust). If it's not doing anything bad now, just leave it. > > In either case, you should pull the vacuum hose off and plug it, THEN > set static ignition timing. > > Another good thing about the later Duraspark distributors is more > aggressive mechanical advance. 1979 vs. 1970, for example, has a lot > more ignition lead. Increases power, at the slight disadvantage that > you need to set timing a little more carefully as it's more ping > sensitive. That's a 50s, 60s mentality (easy, lazy) vs. emissions and > mileage and such. > _______________________________________________ > Amc-list mailing list > Amc-list@xxxxxxxxxxxx > http://splatter.wps.com/cgi-bin/mailman/listinfo/amc-list > _______________________________________________ Amc-list mailing list Amc-list@xxxxxxxxxxxx http://splatter.wps.com/cgi-bin/mailman/listinfo/amc-list