'64 Comet 200 cid dies and where's my LOM port?

[Kustomkarma]

I haven't had any success selling my '64 Comet so I've decided to keep it. I am currently trying to sort out all the little stuff that affects the way it runs. I'm having two main problems. The first is that sometimes the car dies under light load or when just starting off. It will sit and idle all day and seems to run fine when you give it throttle, but at low speed sometimes it just dies. I have a '64 200 cid with an original Load-O-Matic type dizzy and a professionally rebuilt autolite 1100 carb. The cap, rotor, wires, seem to be okay and the fuel tank, pump, and lines have all been replaced. We have adjusted the idle as well as the mixture which seemed to help a little, but did not solve the problem. Anyone got any thoughts?

The second problem I'm having is that my carb has no vacuum port. It has the threads in the body, but the passages aren't there (no holes) it's like it's blocked off. What can I use for a vacuum source for the advance on my Load-O-Matic dizzy? There's a port on my intake manifold that the auto trans (C-4) is tapped into. Can I T off of this? If not what can I do as there aren't any more ports on my intake manifold. :

Any help with this stuff would be greatly appreciated.
Thanks.

 

[bubba22349]

The LOD distrib has to be connected to the carb's port the carb and LOD are matched to work together. The LOD can not be hooked to the manifold or any other vacuum source it just will never work properly.

 

[Frankenstang]

The LOD distrib has to be connected to the carb's port the carb and LOD are matched to work together. The LOD can not be hooked to the manifold or any other vacuum source it just will never work properly.

Yep, just as bubba said...Load-o has to have a matching scv carb. Make sure your carb has a 'working' scv...looks like a holley power valve...


dizzy port for load-o on an 1100 should be same as the one in this pic where the little brass plug with teflon tape is (to the right of the scv)...


Unless you have a non-scv carb then you may want to consider swapping to a non load-o dizzy ('69 and later IIRC including dsII), but a correctly set load-o with matching tuned scv carb (and throw in a petronix unit) can make a fine performing, economical setup.
Lack of proper dizzy to scv advance source could explain poor take off, or possibly a faulty accel pump diaphragm or missing component...but gotta get the advance working before you'll get it performed and tuned correctly.
Good luck!

 

[Kustomkarma]

Thanks for the responses.
I was thinking of switching to a DS II which I would use to trigger a Mallory 6A box that I already have laying around. The carb is a fairly recent professional rebuild, so I'd like to keep it rather than trying to find another with the proper vacuum port.

So to sum it up, I could use my non vacuum ported autolite 1100 with a DS II distributor and a Mallory 6A box and a blaster coil. Are there any other parts I would need to do the conversion? I already have a ballast resistor wired into my ignition system which consists of an entirely new generic style wiring harness.

Could I "T" the vacuum advance from the DS II into my intake manifold where the transmission vacuum line ties in?

 

[bubba22349]

Yes you could do that, should be a good combo of parts. Personally I don't like to use manifold vac. instead I like to use vac. porting off of the carb base. Many use manifold vac. with good results. Go for it! With parts that you it will be much better driver than the old LOD.

 

[Kustomkarma]

It looks like I'm going to go the original equipment route with a DS II, Ford module, and wiring harness rather than the MSD 6A. Does anyone have these original parts that they are looking to sell? I'll be sticking the 6A, Blaster coil, and other misc. up on Ebay.

 

[Kustomkarma]

Actually, I just realized that my engine is a '64. Will the later DS II with the 5/16 oil pump driveshaft fit my engine? I thought I read somewhere that different years used different shaft sizes or is that different sized engines used different shaft sizes. :

 

[Kustomkarma]

Believe it or not, I stumbled upon a '82 Fairmont in the local pick a part today. It just so happened to have a 200 in it. I grabbed the DS II distributor, the wiring, the control box and a couple of vacuum fittings. I was thinking of trying to tap the vacuum advance into the same port where the PCV valve goes into the carb spacer (right under the carb.) Is this a good place to hook up the advance or is there somewhere else that would work better?

Thanks.

 

[bubba22349]

Was the carb you had pro rebuilt the original for the car? Do you know the parts used in it like Frankenstang posted pictures of? If so you will need to mod it too when you change from the LOD.

 

[Kustomkarma]

I believe the carb is a later model year as it has the SCV valve, but no vacuum port. It's not the original carb that came on the car. I told the company (National Carburetor) what I had and that's what they sent me. What needs to be changed?

 

[Frankenstang]

I believe the carb is a later model year as it has the SCV valve, but no vacuum port. It's not the original carb that came on the car. I told the company (National Carburetor) what I had and that's what they sent me. What needs to be changed?

Kustomkarma, any chance you could post a couple pics of the carb and the dizzy? Would make ID'ing what you've got and suggestions on which direction to go from here alot easier.

 

[Kustomkarma]

I tried to post pics, but it looks like they will have to be hosted elsewhere as this site doesn't upload images. Just a quick update. We installed the dizzy and the box last night. The red and white wires were wired to the "+" on the coil, while we put the green to the "-'"side. Would not fire, no spark. We changed out to a new box, again nothing. Checked all wires for continuity and all was good, still wouldn't fire. I think I have a bad magnetic pickup in the dizzy. How can I test this off the car? I heard that rotating it by hand should produce a couple of volts when viewed on a multimeter. Does the dizzy have to have power put to it to do this test? I'm at a loss.

 

[bubba22349]

White wire goes to starter sol. and is used only for the starting position of ign. sw.

 

[Kustomkarma]

Hopefully this works. Here's a pic of the carb in question. The port to the right of the SCV is blocked internally. It's actually cast with no venturi hole in it. http://i114.photobucket.com/albums/n244 ... photo1.jpg

 

[Kustomkarma]

Here's another shot. http://i114.photobucket.com/albums/n244 ... photo2.jpg

 

[bubba22349]

No wonder the LOD didn't work :thumbdown: They must have mixed a bunch of odd parts together to build it, can you send it back : Otherwise you could maybe drill out the passage if you find another carb to copy the details or from someone with the right carb and than you could use the LOD distrib. Or go to the DSII and you would either need to change the carb for a later model unit or mod it to get rid of the SVC function

 

[Kustomkarma]

Looks like I'll need to purchase another carb as I've had this one for about a year and half now. I drive the car so infrequently (about 15 miles in 3 years) that I didn't even realise this was a problem until just recently when the car started cutting out on me in traffic. Which model and year carb do I need if I go with a DS II setup? I have mechanical carb linkage since it's a '64.

 

[Frankenstang]

The port to the right of the SCV is blocked internally. It's actually cast with no venturi hole in it.

That is just wierd, and has me shaking my head...dang rebuilders!...is who I am guessing would have plugged it...may not even be the last rebuilder but one prior to that, or as bubba suggest a mix match of parts.
(side note: I've got an 1100 where someone <likely the rebuilder> plugged one of the ball check passages on the acc pump :x )

I believe David/CZLN6 usually recommends an 1101 from a '69 250 for DSII as it has a ported source for vacuum and 200+ cfm, but no scv (may require opening up your carb base spacer if it's a 1.5" opening IIRC). I still get mixed messages reading posts on preferred vacuum source for DSII...seems to differ depending on your cam setup..stock cam=potentially poor manifold vacuum signal....performance cam=potentially good manifold vacuuum signal...main takeaway 'seems' to be go with a ported vacuum source carb for DSII if you can. AFAIK those running progressive two barrel webers (insert Tim Allen grunt) get a good vacuum signal from the port on those carbs...but don't quote me on this as I've not done this mod (neither 2bbl nor dsII).

From one of my parts carb 1100's...here is what the hole in the lom port should look like...

 

[Kustomkarma]

I contacted the rebuilders today and will be sending the carb back for modification / replacement. At this point I'm thinking of using the DS II dizzy with the proper ported carb (stock LOM ported autolite 1100.) I'm thinking I can use the vacuum port for the LOM to provide vacuum for the DS II advance. Will this work or will I have to use the stock dizzy with a pertronix?

Thanks for all the information so far. Building this car has been an education in pain. I've had the front end completely out 6 times, the rear suspension at least 4 times, and almost every single part I've ordered has been wrong. I even had to do the disc brake conversion 3 or 4 times due to noncompatible parts.

 

[bubba22349]

The short answer is No! I usually will not try to use the LOD and or early carb or parts because they operate so much differently than the later vac. distrib advance system. So my rule of thumb is to use the LOD only with it's early style carb and an early carb only with an LOD. Then if I go to a DSII, which I highly recommend than, I go with a later carb IE 69 up. I have done this DSII swap many times on the 240 / 300 BB6 I when I do I just use the later Holley or a Carter Y series carb. It works the same on the small six as Frankenstang said the Autolite 1101 from a '69 250 would be a good one to use with a much better result. Also I will second that if its at all possible you can you should always try to only use a carb ported vacuum source for the distributor advance on any of the late style distributors. Ask yourself this question why would the engineers have spent the time and money designing it if it’s not the better way to go instead of just hooking it to the intake manifold?

Now to make it even more confusing these early carbs originally used with the LOD distrib can be reworked. I would say its all in according to how much time and amount of patience you have or what you will spend getting it to work right. For the most part if I am doing the job for someone the extra time is the factor and drives up the cost to the customer so I go with a known group of parts that has been proven to work before.