Vacuum advance Distibutor ??
#2762316
04/10/20 01:39 PM
04/10/20 01:39 PM
|
Joined: Mar 2007
Posts: 3,277 West Coast, USA
jbc426
OP
master
|
OP
master
Joined: Mar 2007
Posts: 3,277
West Coast, USA
|
I'm currently running an MSD Pro-Billet distributor that's locked out with an MSD Digital 6 box. I'd like to replace that distributor with a distributor that I can run locked out, and still have a functioning adjustable vacuum advance.
I'm running 35* timing on the Pro-Billet, but want to add more advance using the vacuum feature for street and highway use.
Any suggestions on which distributor would work best. I see a bunch of ready to run distributors, but would like to keep my MSD Digital 6 box.
A laptop adjustable ignition would be nice, but I need the vacuum advance feature too.
1970 Plymouth 'Cuda #'s 440-6(block in storage)currently 493" 6 pack, Shaker, 5 speed Passon, 4.10's 1968 Plymouth Barracuda Convertible 408 Magnum EFI with 4 speed automatic overdrive, 3800 stall lock-up converter and 4.30's (closest thing to an automatic 5 speed going)
|
|
|
Re: Vacuum advance Distibutor ??
[Re: jbc426]
#2762471
04/10/20 07:40 PM
04/10/20 07:40 PM
|
Joined: Feb 2013
Posts: 141 Missouri
randavis
member
|
member
Joined: Feb 2013
Posts: 141
Missouri
|
Couldn't you use a stock distributor with one of those advance limiter plates or just weld up the slots in the centrifugal weights and still allow the vacuum advance to move the plate?
Last edited by randavis; 04/10/20 07:41 PM.
74 Challenger, bought it new. In 1978 I replaced the original 318 with a 446 and 727. Mild cam, Jardine headers, and Holley Sniper EFI. New engine! 511" RB, Edelbrock Performer RPM heads, Eagle rotating assy, Comp hyd roller cam, Doug's 2" headers.
|
|
|
Re: Vacuum advance Distibutor ??
[Re: jbc426]
#2762601
04/11/20 09:06 AM
04/11/20 09:06 AM
|
Joined: Feb 2008
Posts: 714 Central TEXAS!!!!
sr4440
super stock
|
super stock
Joined: Feb 2008
Posts: 714
Central TEXAS!!!!
|
this can easily be done. Get a street distributor, (or stock) Lock down the centrifugal weights (weld?), then use the vacuum advance. The vacuum advance, advances the relector/pickup (or points if your are really old). If you do this the rotor tip needs to be pretty wide, your going to add 45-50 degrees of ignition timing without the rotor advancing. That works out to 22.5-25 angle of degrees and with a terminal every 45 degrees, misfires might be a issue.
Joe
edit MSD sells a adjustable rotor that will help with phasing. part # 84211
Last edited by sr4440; 04/11/20 09:25 AM.
Without Data, you’re just another guy with an opinion.
|
|
|
Re: Vacuum advance Distibutor ??
[Re: sr4440]
#2762675
04/11/20 12:25 PM
04/11/20 12:25 PM
|
Joined: Mar 2007
Posts: 3,277 West Coast, USA
jbc426
OP
master
|
OP
master
Joined: Mar 2007
Posts: 3,277
West Coast, USA
|
this can easily be done. Get a street distributor, (or stock) Lock down the centrifugal weights (weld?), then use the vacuum advance. The vacuum advance, advances the relector/pickup (or points if your are really old). If you do this the rotor tip needs to be pretty wide, your going to add 45-50 degrees of ignition timing without the rotor advancing. That works out to 22.5-25 angle of degrees and with a terminal every 45 degrees, misfires might be a issue.
Joe
edit MSD sells a adjustable rotor that will help with phasing. part # 84211 I have the MSD adjustable rotor in there already. My phasing was so far off to begin with. Also, the 2 wires coming from the MSD Pro-Billet were swapped from the manufacturer, which didn't help. Once I got all that sorted, I was unable to get stable initial timing as it was bouncing with the light springs being unable to hold the mechanical advance steady at 900 rpm. That's when I experimented with locking out the distributor. Now that all those issues are resolved and the car being easy to start hot or cold with 35* of timing, I rephased the rotor to line up at that timing setting. I assume I will only be adding 10* to 15* of vacuum advance to it, not the whole 45* or 50*, so there will be much less change in relation to the rotor tip and the terminals.....Right? I don't have the newer programmable MSD. I'm assuming a programmable ignition system would need input from both a MAP sensor and a TPS to replicate a vacuum advance curve. Can anyone who knows about that sort of stuff confirm that? Rich or Andy would surely know.
1970 Plymouth 'Cuda #'s 440-6(block in storage)currently 493" 6 pack, Shaker, 5 speed Passon, 4.10's 1968 Plymouth Barracuda Convertible 408 Magnum EFI with 4 speed automatic overdrive, 3800 stall lock-up converter and 4.30's (closest thing to an automatic 5 speed going)
|
|
|
Re: Vacuum advance Distibutor ??
[Re: AndyF]
#2762772
04/11/20 05:18 PM
04/11/20 05:18 PM
|
Joined: Aug 2003
Posts: 43,127 Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,127
Bend,OR USA
|
Andy, will a MSD grid do what he needs with his current MSD parts?
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
|
|
|
Re: Vacuum advance Distibutor ??
[Re: jbc426]
#2762816
04/11/20 07:21 PM
04/11/20 07:21 PM
|
Joined: Feb 2008
Posts: 714 Central TEXAS!!!!
sr4440
super stock
|
super stock
Joined: Feb 2008
Posts: 714
Central TEXAS!!!!
|
yes, your just going to add another 15-18 degrees. being able to advance the rotor should clear up any misfires.
Joe
Without Data, you’re just another guy with an opinion.
|
|
|
|
|