Help upgrading carb and ignition system.

Boots_N_Slicks14

New member
Still learning here.. Currently I have a Holley 1940 and the load-a-matic dist. in my '62 Comet with a '65 200 engine. I was lucky enough (or thought I was) to find a '79 Fairmont in the JY with a 200 which still had the Holley 1946 and Duraspark II ignition system intact. I grabbed both the carb and complete ignition system from the Fairmont with the intent of using the parts to upgrade my Comet. Well, I was disappointed to find out that that later carb won't fit unless I used an adapter (I already converted the throttle linkage to cable).

What I was wondering is:

1) Is it worth going through the trouble of making an adapater to use the 1946?

2)What other options do I have as far as carbs to use with the Duraspark II ignition system?

3) Do I have to run all the vacuum lines and control valves for the ignition system that were originally on the Fairmont donor car or can I just have a single vacuum line going to the carb from the dist.?

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1. It might be if the carb is in good condition

2. The Autolite 1101, Carter YF, and RBS in 2V's the Autolite/ Motorcraft, Rochester 2Jet, Holley 350 / 500, and the Weber carb's. Any of these carb's will be much less work to install then the Holley 1946.

3. Since you don't have any of the Smog emissions system that the 1979 Fairmont had all you really need to hookup is the vacuum line to the distributor. But adding the PCV system parts would be a good move too if your not already running one. Good luck :nod:
 
Howdy B_N_S:

Good get on the DS II. To bad you didn't get the spark plug wires and the wiring harness that connects the distributor to the coil and module. It is a nice package and saves time when wiring for the new application.

I'm having difficulty seeing if the Spark Control Valve (SCV) is in place on the 1940 carb. Is it there? The DS II is a slam dunk- no brainer. Only thing better is to have it's advance recurved to your application.

All of the Upgrade carbs suggested above will have a ported vacuum source for the DS II vacuum advance. Each will require a bit of modification to the carb adaptor to allow the butterfly valve to open. They are worth it. Given you've already went to a late style valve cover and linkage I'd recommend the Carter YF carb. They offer several sizes/applications.

Great car! keep it coming. Good Luck

Adios, David
 
There are other good parts on that Fairmount. Air cleaner, exhaust manifold actually the whole engine and trans.
 
bubba22349":3no66ghw said:
1. It might be if the carb is in good condition

2. The Autolite 1101, Carter YF, and RBS in 2V's the Autolite/ Motorcraft, Rochester 2Jet, Holley 350 / 500, and the Weber carb's. Any of these carb's will be much less work to install then the Holley 1946.

3. Since you don't have any of the Smog emissions system that the 1979 Fairmont had all you really need to hookup is the vacuum line to the distributor. But adding the PCV system parts would be a good move too if your not already running one. Good luck :nod:


Thanks. I'd like to stay with a single barrel carb, I tried running a 2 barrel with an adapter and couldn't get my hood to close no matter what air cleaner I used. Are there any single barrel carbs that will fit my current intake that are actually a higher CFM rating than the 1940 I'm running? If so, what vehicles did they originally come on, or where they aftermarket?

That's what I thought about vacuum line, wasn't sure though.
 
CZLN6":3svrja0a said:
Howdy B_N_S:

Good get on the DS II. To bad you didn't get the spark plug wires and the wiring harness that connects the distributor to the coil and module. It is a nice package and saves time when wiring for the new application.

I'm having difficulty seeing if the Spark Control Valve (SCV) is in place on the 1940 carb. Is it there? The DS II is a slam dunk- no brainer. Only thing better is to have it's advance recurved to your application.

All of the Upgrade carbs suggested above will have a ported vacuum source for the DS II vacuum advance. Each will require a bit of modification to the carb adaptor to allow the butterfly valve to open. They are worth it. Given you've already went to a late style valve cover and linkage I'd recommend the Carter YF carb. They offer several sizes/applications.

Great car! keep it coming. Good Luck

Adios, David

David,

Appreciate the response. It was probably tough for you to see in that pic, I did actually get everything you mentioned. Should be able to see it better now. As far as wiring, I could definitely use help with that. I've seen diagrams elsewhere for a stock factory setup, however, I'm not sure if I need to wire everything pictured? I'd like to keep the engine compartment as least cluttered as possible..

You bring up a good point with the SCV. I never noticed, I don't have one. This probably explains, the miss, rich idle and flat spot I have when accelerating ever since I've had the car. I don't see how a SCV would even fit on my carb since there are no threads inside the provision?

Is the Carter YF any bigger CFM wise?


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Howdy back:

Since the 1940 is not a SCV carb, and if it has a ported vacuum port it may be a good match with your new DS II. It is impossible to tell what size it is too, without some measuring of the throttle bore and the inside diameter of the venturi. The problem is that the 1940 was a generic carb that Holley modified for FoMoCo after the demise of the Autolite Corp. They were made to fit every engine that FoMoCo ever put Autolites on. So the cfm rating on your carb could be any where from 150 to 210, but most likely in the 185 range. Carter YFs from a 250 engine were rated at 215 cfm while the YF from a pickup with a 300 engine was rated at 220 cfm. The YFs will have a larger T-bore but your cable linkage will make it easier to adapt.

Both of these carbs will make for a nice increase in power, but I'd favor the one from a 250 because the ones from the 300 truck engines has some richer internals which may be tough to lean out. That makes them hardly worth it for 5 extra cfms that will only really counk at full throttle.

Does your car have an auto or manual trans?

I hope that helps. Good luck searching.

Adios, David
 
CZLN6":knmjwftq said:
Howdy back:

Since the 1940 is not a SCV carb, and if it has a ported vacuum port it may be a good match with your new DS II. It is impossible to tell what size it is too, without some measuring of the throttle bore and the inside diameter of the venturi. The problem is that the 1940 was a generic carb that Holley modified for FoMoCo after the demise of the Autolite Corp. They were made to fit every engine that FoMoCo ever put Autolites on. So the cfm rating on your carb could be any where from 150 to 210, but most likely in the 185 range. Carter YFs from a 250 engine were rated at 215 cfm while the YF from a pickup with a 300 engine was rated at 220 cfm. The YFs will have a larger T-bore but your cable linkage will make it easier to adapt.

Both of these carbs will make for a nice increase in power, but I'd favor the one from a 250 because the ones from the 300 truck engines has some richer internals which may be tough to lean out. That makes them hardly worth it for 5 extra cfms that will only really counk at full throttle.

Does your car have an auto or manual trans?

I hope that helps. Good luck searching.

Adios, David


So by the sound of what you're saying, not all the Holley 1940 carbs came with a SCV?

Yes it has a ported vacuum source, however, if I was to try and run the DS II ignition with this carb, I would definitely use manifold vacuum, not the ported source.

Going off another thread here, I believe my current 1940 is 185 CFM.

Will the Carter YF you mentioned that was used on some 250 engines have the same bolt pattern as my current intake? I understand I may have to enlarge the opening on the intake to clear the butterfly.

My car has a 2 Spd Ford-o-Matic..
 
:unsure: Hi Boots.Ported vacuum is the way to go.With manifold vacuum,you will have almost full advance at idle,and almost none on acceleration.The wider that the throttle is opened,the less vacuum you have.If this is incorrect,someone please correct.
Good luck.Have fun.Be safe.
Leo
 
Howdy Back:

Yes, some rare 1940 did not have a SCV.

I'm in agreement with Leo. The DS II system was designed to be used with a ported vacuum source. You could try both, but know that with manifold vacuum you will likely have to reduce initial advance to avoid too much advance at hiway cruise speeds when all three, initial, mechanical and vacuum, in effect. I noticed both peppering and glazing on the plugs when I tried it. I experimented with both manifold and ported vacuum and no vacuum advance at all. For me, in every day driving, ported vacuum worked best.

Does your two speed trans use a kick down linkage to the carb?

On the YFs, an adapter was used to orient the carb, same as with the original Autolite. I don't recall which adapter I used. Several on this forum have made their own adapters. IIRC that was to orient the carb to be able to use the stock mechanical linkage. If you're going to the recycle yard to find a core carb, get the adapter too.

Adios, David
 
Boots_N_Slicks14":1n17wkru said:
CZLN6":1n17wkru said:
Howdy B_N_S:

Good get on the DS II. To bad you didn't get the spark plug wires and the wiring harness that connects the distributor to the coil and module. It is a nice package and saves time when wiring for the new application.

I'm having difficulty seeing if the Spark Control Valve (SCV) is in place on the 1940 carb. Is it there? The DS II is a slam dunk- no brainer. Only thing better is to have it's advance recurved to your application.

All of the Upgrade carbs suggested above will have a ported vacuum source for the DS II vacuum advance. Each will require a bit of modification to the carb adaptor to allow the butterfly valve to open. They are worth it. Given you've already went to a late style valve cover and linkage I'd recommend the Carter YF carb. They offer several sizes/applications.

Great car! keep it coming. Good Luck

Adios, David

David,

Appreciate the response. It was probably tough for you to see in that pic, I did actually get everything you mentioned. Should be able to see it better now. As far as wiring, I could definitely use help with that. I've seen diagrams elsewhere for a stock factory setup, however, I'm not sure if I need to wire everything pictured? I'd like to keep the engine compartment as least cluttered as possible..

You bring up a good point with the SCV. I never noticed, I don't have one. This probably explains, the miss, rich idle and flat spot I have when accelerating ever since I've had the car. I don't see how a SCV would even fit on my carb since there are no threads inside the provision?

Is the Carter YF any bigger CFM wise?


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It's fairly easy to strip down the wire harness I recently did this for a site member using a Fox chassis harness. You remove the outer wire lum cover and remove the extra wires that are not for the ignistion system. Then reinstall the wire cover or use some electrical tape to make a new cover. good luck :nod:
 
CZLN6":2wtso7sr said:
Howdy Back:
I'm in agreement with Leo. The DS II system was designed to be used with a ported vacuum source. You could try both, but know that with manifold vacuum you will likely have to reduce initial advance to avoid too much advance at hiway cruise speeds when all three, initial, mechanical and vacuum, in effect. I noticed both peppering and glazing on the plugs when I tried it. I experimented with both manifold and ported vacuum and no vacuum advance at all. For me, in every day driving, ported vacuum worked best.
Adios, David
I can reduce the amount of vacuum advance & then you can run your initial + centrifugal for best power.
Vacuum helps fuel mileage & helps part throttle drive-ability.
In some engine combinations manifold vacuum can help idle quality. However do not use manifold vacuum as a crutch for a improper centrifugal curve.
On a stock engine ported vacuum works better.
I would bet 75% of forum owners do not have a proper advance curve for their engine combination.
There are many vacuum advance canisters that have different total advance in degrees.
Also most adjustable vacuum advance canisters come it different total advances.
I tailor my distributors vacuum advances for the application.
Many of my customers on this forum can see what i have done.
David let me know you application & i will be glad to fix one for you. Bill
 
@ Woodbutcher and CZLN6: It seems that I'm getting conflicting info here regarding if I could use manifold vacuum for the DS II dist.

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In those threads, a couple of members have posted using manifold vacuum as a source for their DS distributors with the early SCV carbs.. Of course I would use ported vacuum IF that was an option.

Looks like I'm going to stick to my original plan of trying to make the carb that came off the Farimont work. I'm just surprised no one makes an adapter..

Looks like this going to be another project. I'm kinda wishing I just went the Pertronix route in the first place, less complicating.

And to answer your question David, no kick down linkage.
 
@Bubba: I would just like to know which extra wires that are not for the ignition system I can remove.. Everything else seems pretty straight forward..
 
@ Boots _N_Sticks, here is a post I did a few days ago about how to hookup the DSII.

"On my 1965 F-350 I used the compleate stock DuraSpark II system right out of the junkyard. It's a great upgrade and for your planed use the stock system is all you will need. When you get all the parts be sure to get the wire harness too, look for a 1975 to about 1983 DSII off a 300.

When using a compleate stock wire harness and a Blue strain (ICM) it's Pertty much Plug and Play. The 3 wire plug connects to the distributor and then the 4 wire plug goes into the ignition control module (ICM). When using the stock Ford DS II coil and its special horse shoe connector then it only plugs togeather one way too. That leaves hooking up the orginal coil + wire to the + coil wire of the DSII horseshoe clips, next the two wire plug from the (ICM) it has Red and White wires the Red wire connects to the ignition switch Pink wire test the voltage 3 or 4 inches from the back of the ignition switch plug the voltage there should be a full 12 + volts, splice it in the new wire to the Red wire on the ICM 2 wire plug. Then the White wire connects to the S terminal of the starter Solenoid, thats about all there is to it. Good luck :nod:"


Stripping down the DuraSpark II to a stand alone system.

Now it dosnt matter which Ford engine your working with when using all the stock Ford DSII system parts it will hookup the same way! Next the only wires you will need from the harness to run the DSII are those with the 3 and 4 wire plugs, the coil horseshoe plug and its wires, plus the two wire plug that connects into and powers the ICM. All these wires will plug togeather into the distribitor, into the ICM, the coil, and coming out of the ICM again this is everything wiring wise that's needed for a stand alone DSII system. The other extra wires of your Fairmont wire harness are going to the carb and engine oil, water temp senders plus connecting the ignistion harness into the Fairmont's main wire harness. If you plan to use the 1946 Holley then you could leave the harness alone for now.

Since you said your Holley 1940 dosent have a SCV then you are all set and can use it with the DSII as is to try it out. X3 I also like to use the carb's ported vacuum line to the distributor's vacuum advance for a street driver its usally the best way to go. Good luck :nod:
 
There a number of ways to wire a DuraSpark II system (DSII) depending on how much rewiring of your car you want to do.

Here is how I did it on a number of early cars and trucks that is very simple and it keeps and uses all the orginal wiring only adding one or two new wires. Also if you should ever want to return to the stock system it's easy to change back.

1. With the new DSII Distributor installed its 3 Wire socket pluggs into the DSII wire harnesses 3 wire plug and then you can start to route the DSII wire harness.

2. The Ignition Control Module (ICM) gets mounted to the inter fender panel and the DSII harness 4 wire plug goes into the ICM 4 wire socket. Some people run an extra ground wire to one of the mounting screws if the inter fender panel is made of metal it probally isn't nessisary but it won't hurt if you want to.

3. I used most all of the stock vehicle wiring including the Pink Resistor wire that goes to the Bat. Or + Side of the stock Ford coil. This Pink wire goes right into the DuraSpark II coils Red wire hooked up to the Battery or + side of the new DSII coil. Also the other wire coming from the I terminal ( for extra voltage when starting) of the starter solinod goes onto this same + Red wire.

4. The DSII horseshoe clip is made so that the Green wire coming out of the DSII wire harness plugs onto the Tach or the - side of the coil, so you just plug it on as is.

5. The ICM 2 wire plug socket is plugged into the 2 wire plug and has a Red and a White wire coming out of it. I ran a new wire connecting this Red wire and splicing it into the Pink wire about 2 or 3 inches under the dash behind the ignistion switch so it's before the Resistor in the Pink wire, I even used a Crimp On type Splice Connector so I didn't have to cut any of the orginal wiring harness. If you have a Volt / Ohm meter probe the wire there you are looking for at least a full 12 + volts with the Key on in the Run position as the ICM needs a full 12 volts to run correctly. This is all you really need to make it run and many people don't even bother to hookup the White wire. The White wire though is the Ignistion retard feature of the ICM and is a good idea to hookup. To do so just run a new wire connecting the White wire over to the S terminal of the starter solenoid and now your all done and can Enjoy all the benifits of the new DSII system. Good luck :nod:
 
@Bubba: Reading your last post might explain why I was up late last night trying to figure out why I wasn't getting any spark out of my coil.. So the wire that used to go the POS side of my old coil goes to the POS side of the new DS II coil? (That makes more sense to me)

I hooked the old wire that went to the POS side of my old coil to the red wire that comes out of the ICM, (not on the coil) I also hooked the the white wire coming out of the ICM directly to the I terminal on the solenoid. (Because I thought that's what you said in post #16)


I'll try hooking it directly to the coil and see if that makes a difference.. (It should).
 
Boots_N_Slicks14":lvz5kta2 said:
@Bubba: Reading your last post might explain why I was up late last night trying to figure out why I wasn't getting any spark out of my coil.. So the wire that used to go the POS side of my old coil goes to the POS side of the new DS II coil? (That makes more sense to me)

I hooked the old wire that went to the POS side of my old coil to the red wire that comes out of the ICM, (not on the coil) I also hooked the the white wire coming out of the ICM directly to the I terminal on the solenoid. (Because I thought that's what you said in post #16)


I'll try hooking it directly to the coil and see if that makes a difference.. (It should).

Yes you are right the orginal coil wire is hooked to the + side of an aftermarket coil or it can say Bat. on a stock orginal Ford coil eigher way it's wired the same as it was with the old point distributor. This orginal Pink Resistor wire goes to the horseshoe clips Red wire for the Bat. or + side of the new DSII coil.

The ICM red wire needs to be a separate new wire that is hooked up so when the key Is on in the Run position it will have a full 12 + volts (see the above posts instructions) to operate correctly. Hooking the Pink or + coil wire to the ICM's Red wire won't give the correct voltage to the ICM.

Yes your right I had made a typo last night on the White wire instructions I am sorry about that, but I have since corrected that in the above post. The White wire if used needs to be connected onto the S terminal of the starter solenoid this will trigger the retard function of the ICM for easier starting. Good luck you should have it going real soon now. (y)
 
bubba22349":38je4fbr said:
Boots_N_Slicks14":38je4fbr said:
@Bubba: Reading your last post might explain why I was up late last night trying to figure out why I wasn't getting any spark out of my coil.. So the wire that used to go the POS side of my old coil goes to the POS side of the new DS II coil? (That makes more sense to me)

I hooked the old wire that went to the POS side of my old coil to the red wire that comes out of the ICM, (not on the coil) I also hooked the the white wire coming out of the ICM directly to the I terminal on the solenoid. (Because I thought that's what you said in post #16)


I'll try hooking it directly to the coil and see if that makes a difference.. (It should).

Yes you are right the orginal coil wire is hooked to the + side of an aftermarket coil or it can say Bat. on a stock orginal Ford coil eigher way it's wired the same as it was with the old point distributor. This orginal Pink Resistor wire goes to the horseshoe clips Red wire for the Bat. or + side of the new DSII coil.

The ICM red wire needs to be a separate new wire that is hooked up so when the key is on in the Run position it will have a full 12 + volts (see the above posts instructions) to operate correctly. Hooking the Pink or + coil wire to the ICM's Red wire won't give the correct voltage to the ICM.

Yes your right I had made a typo last night on the White wire instructions I am sorry about that, but I have since corrected that in the above post. The White wire if used needs to be connected onto the S terminal of the starter solenoid this will trigger the retard function of the ICM for easier starting. Good luck you should have it going real soon now. (y)



Yep, I got it going. Thanks!

Surprisingly fired on the first try.

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Adds a little excitement to the engine compartment.


Noticed it starts easier when cold and a little more power. I had my old points ignition dialed in pretty good so I didn't notice the huge power increase some claim they do. Still happy I upgraded. Now if I could get that other carb on there and address the flat spot issue that I still have..

Currently got the timing at about 14 Deg. and the spark plug gap at .045".

In case anyone else comes across this thread and is more visual, the Painless site has a nice diagram that explains how to wire the DS II system as well.

http://www.painlessperformance.com/Manuals/30812.pdf

Looking at the Painless diagram,that's how I pretty much ended up wiring mine minus the ballast resistor and the white wire going to the S terminal on the solenoid, which is pretty much what Bubba stated.
 
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