DS-II Dizzy Questions

[mustang652]

Got all the parts for a DS-II conversion last week from the local pic a part yard (picked up two sets just to have parts back-up) and after severa hours of cleaning the better looking set I am ready to attempt the install. An old quotations states that, "When all else fails, read the instructions dummy" I did and I'm still confused on exactly where to hook or splice in the Red wire under the dash and should I use the white wire and if so does it go on the S terminal. the picture in the sticy is a little dark and hard to tell what is what. Looking at mustangSteve's diagram (same sticky), it appears that the added white wire goes to the S terminal and the red should go onto the terminal of the heavy pink resistor wire. Ill be using the 1100 Autolite until later ths spring, What do I do for the vacumme advance and should I attempt the recurve.

 

[t-west]

You need to tap into the "pink" wire "ahead" of where the resistance takes place so you get a full 12V for the module (if you're using a 12V coil, same thing -- you can effectively dissocnnect the pink wire and run a new one then). This is much easier to see if you remove your instrument panel.

As for the white, yes it goes to the S on your solenoid.

As for the recurve, it depends on your mods IMO. Did you ever get that 3X1 installed? Head mods? Cam?

As for advance, I made the change to a 5200 at the same time, so I'm not much help. You might be able to hook the SCV from your carb to the vac advance and "cobble" it together. I'll let others give their advice on this.

 

[mustang652]

Thanks, got the dash apart and am having trouble finding the thick pink wire. No mods right now, hope to do the 3 X 1 and engine work in late spring and early summer. Currently I'm finishing up sanding down car hoping to have repainted right after carb and cam work completed.

 

[mustang652]

Finally found Pink wire, it was covered with a cloth casing, but still have a couple of questions. Do I do the splice the red wire into the pink wire or into the red wire with the blue stripe or do I cut out the bullet connector and splice all three togather with a wire nut. Other questions pertain to the coil. I've got a Flamethrower coil, can it be used instead of the Duraspark coil and can the existing harnes to the positive side of the coil be used as it is now.

 

[t-west]

I think I cut the connector off the red/blue wire and spliced a new connector with the new red on that. I'm running the flamethrower coil, but it likes a full 12V, so I needed a new power lead to that as well -- this makes the pink wire entirely obsolete.

--tom

 

[Anonymous]

The 'S' terminal on the selonoid is a 12V wire that by-passes the resistor for 12V to the coil during cranking this is where the white wire for the DS2 goes -it triggers a little spark retard for better starting. The stock wire does not go anywhere any more but it holds the white wire on well.

If you use this and a 12V coil(such as a flame thrower) the red wire can go anywhere that is hot when key is in 'RUN' position, such as the back of the ignition switch. Typically the on position is not hot when key is in 'cranking' position. Therefore it won't start if you wire without the bypass area involved till you let go of the key.

the box above the selonoid is a circuit breaker for stuff inside that is connected directly to the batt, has nothing to do with ign. sys.

here you can see both ends of DS2 harness from junk yard- must be 4' long , best $5 and trip to the JY I've done makes it real easy to clean up wireing.

in this pic +side of coil has power in(green--should be red also)power to module(red) power to fuel pump(black--also should be diff color)
- side has 2 green wires 1 goes to module and the other to tach.
I ran a wire from a lighted rocker switch ( from the 'on' position of your ign. switch would do the same)to the + side of a 12V coil and then the red wire from the mod. to the same + post. also added a wire from there to my fuel pump. This way i can have the key on without putting juice to the engine compartment. Intend to put fuel pump on it's own switch eventually. This engine has about 1,200 miles on it therefore a lot of this stuff is in development yet, so ignore little things like bad wire color choices and some poor looking connectors. The rubber isolaters under the module and coil are probally not necessary but they were in the coffee can that the screws and washers were in and I figured it couldn't hurt.

 

[jamyers]

My pink wire went to a bullet connector by the ignition switch, so I just replaced it on that end. The other end of the pink wire went into the firewall plug, and I cut it close to the plug and crimped the new ignition feed onto the inch or so left of the pink wire - checked it with a voltmeter afterwards, and there's not enough of the pink resistor wire left to make a measurable difference. Then I used the original ignition lead under the hood.

The vacuum advance can on a later non-SCV distributor won't like the vacuum signal from the SCV on the carb, but no problem - Simply tap it into any manifold vacuum source below the throttle valve (PCV port, or often there are ports with threaded plugs in them you can use) and you're on your way. Cap off or plug the SCV outlet on the carb, and don't look back.

You can recurve the distributor by changing the weights/springs/limits later on, whenever you get around to it.

 

[mustang652]

It’s Alive! At least that’s what I think Dr. Frankenstein said when he connected the leads to his monster and it arose from the surgery table. Late yesterday evening after struggling off and on for a week, finally got the Dizzy II together enough to trial start the car. The Monster actually started and ran. This has been one of those, if it weren’t for bad luck, I’d have no luck at all situations. With the heat here in NV, the insulation on the wiring of the Dizzy II’s connectors, the clip for the coil and my ignition switch were brittle. Had to replace the two wire connectors with bullet connectors and jury rid a connection for the coil clip to the harness connector. Still not happy with that fix. Wish I could use the Flame thrower without having to bypass the resistor wire. On the 3rd attempt with only about an inch of the red and blue stripped wire left and removing the ignition switch to get room to work, I finally got the splice in place. This is where the real fun began, I spent the next two days trying to figure out why it would only start off the remote switch. The new wires only went to where they would be connected, but were taped off. For those of you who are better mechanics than me, you’ll get a good laugh. After taking the ignition switch out twice more and totally rewiring switch and checking for shorts several times, it was being that the bushings on my linkage need replacing, and the neutral safety wasn’t engaging properly while in park. Anyway, it’s running and I want to say thanks for those who responded with their help and advice.

Couple more questions if I may. With 14-15 BTDC the advance vacuum line and hose are right up against the oil dip stick, any advise on this, and I’ve got this vacuum line hooked up to the original vacuum port on the 1100 and Will this pose a problem.

 

[jamyers]

Yay! Glad you got it all sorted out. I hate electrics for just those reasons...pesky connectors and taped-off wires.

I'm assuming you've got an Autolite 1100 carb with the dreaded SCV. DON'T hook up the DSII vacuum advance can to the SCV, you'll get really odd advance timing that won't ever go away, so it'll probably ping like crazy. Instead, hook it up to a port coming out of either the manifold or carb adapter so it'll have full manifold vacuum. Most any place can sell a pipe-thread-to-hose-barb brass fitting. And then leave it there if you ever convert carbs, manifold vacuum is the way to go on a non-emissions engine. Cap off the SCV port on the carb, and away you go.

You oughta be able to set the initial timing (vacuum disconnected) to 12-14 degrees BTDC, then back it off if you hear pinging.

You can pull the distributor back out and re-stab it in oriented away from the dipstick no problem, Just mark the rotor's orientation to the dist. body and be sure the rotor ends up pointing at the same part of the distributor body when you're done. Make sense?

 

[mustang652]

Thanks a million, off and running on most of what you've given me. A port for the advance escapes me. The only ports I have or can see below the carb are the port in the carb spacer for the PCV and the port just below in the intake is that used for vacuum line for the transmission.

 

[t-west]

Don't worry about the vacuum advance. Manifold vacuum won't give you what you want (advance under load) anyway. It'll give you initial advance, but when you open the throttle, manifold vacuum decreases, "lowering" your advance in the dizzy.

Wait until you can upgrade the carburetor, then find a ported vacuum.

--tom

 

[jamyers]

And I've got to disagree about the vacuum advance source.

Ported vacuum advance is simply vacuum advance that's taken from a port just above the throttle plate's idle position, so there's no vacuum advance at idle. The only reason to use it is so that the vacuum advance goes away at idle, which raises the combustion temps in order to reduce idle emissions.

Using manifold vacuum for the dist advance is better/simpler for a street non-emissions engine, and much easier to tune for, since the advance doesn't "leap in" just above idle when the port is uncovered.

Mustang652, either of those ports (PCV or trans) are a good source of manifold vacuum for the distributor. You can get a "t" fitting at most any autoparts store, along with a hose barb for the vacuum line. If you want to keep the steel SCV vacuum line you can use a short bit of rubber hose on each end like I did.

While you don't need vacuum advance, you'll be giving away a good bit of gas mileage by not using it. Why not go ahead and hook it up? Then you can use whatever carb you want.

Here's a pic of the two sources of manifold vacuum, the carb adapter and the manifold itself. I've got the carb adapter going to the distributor, and the manifold to the pcv (manual tranny).

 

[kspageddie]

I have been following this post as I am about to install my DII and I am going to use the manifold vacuum port as well. However, I am having a hard time finding a fitting to thread into the manifold. The bolt that was in the manifold is a 1/2 by 13 pitch.

Thanks in advance (pun intended)

 

[t-west]

Hi guys,

I'm trying to figure this out as well -- I thought I knew something, but now am questioning.

Here's what I don't understand: if manifold advance is there from the start, why use it? Couldn't you just disconnect it and advance your timing by turning the dizzy the same amount that the vacuum advance would provide?

Or, does the manifold vacuum decrease as load increases? If this is the case, vacuum advance would work when mechanical advance isn't and vice versa.

I thought the goal was to have the advance increase as the rpm's increased. Perhaps I'm wrong. (BTW, I've tried both vacuum sources and don't see much difference in everyday driving; however, I haven't mapped my advance with each source.)

--tom

 

[MustangSix]

Most stock engines don't like a lot of advance at idle. that's one reason to use the ported tap; you kill that portion off until the engine comes off idle. It makes sense since the engine is turning very slow and there is no reason to light the mixture too soon. Lighting the misture too soon leads to hard starts or poor idle because the combustion is pushing back on a rising piston.

Once off idle, the port "sees" the manifold, but the vacuum will be low because the engine will have an increased load. The vacuum will begin to build again as the load drops and/or speed increases. Once off idle, there is NO differnce between the ported and manifold sources.

 

[mustang652]

MustandSix, thanks for the added imput. Since I can't plug the vacuum adv line into the SVC on the carb, and I hope within the next four months to have my 3 X 1 system to go I'm in a bit of a confused state. Since the spacer plate goes away, that only leaves me with the vacuum on the intake below the carb. As I have to provide for PCV, Vac adv and the automatic transmission line. What do I do ? When I do the head in late March, do I have the machanist creat an additional port on the manifold, and if so where?

 

[jamyers]

kspageddie, I'm pretty sure the holes are tapped for pipe threads, which are different from bolt threads. Most any parts house should have an assortment of fittings that will work.

t-west, Your second thought about vacuum advance was right - it only comes into play under low-load conditions, and goes away under load. At high rpm and low load - say, going down the street at 4000rpm in first gear - you can have as much as 45 or 55 degrees of advance (say, 14 initial + 22 centrifugal + 12 vacuum = 48 degrees), but that's not common. I hope not, anyway. Hopefully, most of the time you're at 4000 rpm you've got your foot in it and there's not that much vacuum advance.

MustangSix, I'm still not sure ported's better, although I'll definately agree that in many stock emissions engines (early 70's and up), if you change from ported to manifold without changing anything else you can get into trouble. And for engines with cams, ported vacuum advance can absolutely help starting issues. But I still like manifold vacuum in conjunction with a good distributor recurve. Most every stock engine I've ever tuned (from MGB 4's to Buick 455's) liked more advance at idle, it generally gives more rpm so I can them drop the carb idle screw and save a little fuel, plus then you don't have to deal with the possibility (unusual, but still a possiblilty) of an engine that likes to really rev (surge) coming off idle when the vacuum advance kicks in (aka Buick 350's).

Did some internet searching, here are a couple of good articles on ported vs. manifold: the consensus seems to be that either is good, it depends on the engine and the rest of the tuning.

http://home.comcast.net/~chadwick.rober ... lained.pdf

http://www.chevyhiperformance.com/howto/46178/

http://www.centuryperformance.com/timing.asp

But since mustang652 has a carb with SCV and not a ported vacuum port available, I still think he ought to go with manifold vacuum. I also advocate his finding out when his centrifugal is all in, and how much it adds, and then maybe modifying that (simple dizzy recurve).

 

[jamyers]

MustandSix, thanks for the added imput. Since I can't plug the vacuum adv line into the SVC on the carb, and I hope within the next four months to have my 3 X 1 system to go I'm in a bit of a confused state. Since the spacer plate goes away, that only leaves me with the vacuum on the intake below the carb. As I have to provide for PCV, Vac adv and the automatic transmission line. What do I do ? When I do the head in late March, do I have the machanist creat an additional port on the manifold, and if so where?

Don't be confused, MustangSix and I are pretty much splitting hairs - the only difference in ported and manifold vacuum is at idle, nothing more.

I don't think any of the carbs used in 3 X 1 setups have ported vacuum ports, all I've ever seen are the early SCV carbs. So you'd have to use manifold vacuum anyway.

Don't need any machining to get another port. Just pull the current fitting out of the manifold, go into any decent parts store (O'Reilly's, NAPA, etc) and tell the parts guy you want a t-fitting the same thread size so you can add a hose barb (and a hose barb). Oughta cost less than a buck apiece.

Actually, you're going to want a 4-way brass fitting, so you can have a place for the pcv that's in your carb adapter once you make the 3 X 1 swap and it goes away.

 

[mustang652]

Want to pass on my thanks to all who have posted and given help and advice on this phase of my project. About ten years ago I had reached the point of getting rid of the car. The engine was about gone, the body in poor shape. Couldn't get any support for my ideas, and caught nothing but flack about wanting to build up and have a nice six instead of converting to a big 8. Met a guy with a '65 200cid fastback with the 3 X 1, modified cam, with built up 170 cid head and beefy suspension. Well that did it, got recommitted to my basic ideas. I wanted to have the best looking 6 banger Mustang in LV and eventially one that would run well above the average. Other than I replaced the engine myself , I really wasn't willing to bo much beyond trying to have a nice looking engine compartment and cleand body and paint until I stumpled into this site. As time goes on, I hope I don't wear out my welcome on asking questions because I'm sure I'll be back to ask more. Thanks again