Twin Weber DCNF carburetors linakge setup

andreav

andreav

True Classic
Guys need advices, infos or photos on connectiong linkages for twin DCNFs for X/128. I find person who is able to made linakges, we made some basic design which will work to connect carburetors together but we want still to add place for throttle linkage/cable ball?
If someone can post photos how is this done will be nice?
If someone interested will be for sale linkages as soon as are ready.
 
I'll have to check my pictures. I can't help with the interlink, should be straight forward. I did put dual Webers on a few 128s and used the stock type rod linkage with some modifications to have it pull properly on the Webers.
 
For 128 understand and I m more familiar, they use throttle cable on right side of valve cover and by that understand that is on side possible to attach, but on X I look photos and offten is made metal link which connect cover and carbs.
Or at least I want to made linkages for connect twin DCNF because at moment they dont exist somewhere for sale?
In past Alquati made this but today no one do anymore.
 
128 uses a mechanical, multi rod connection from the gas pedal to the carb, no cables involved.
 
These links aren't specific to the X1/9 or any Fiat, but there are lots of images of Weber linkage parts. It may help with ideas.
https://www.piercemanifolds.com/category_s/223.htm
https://www.piercemanifolds.com/category_s/181.htm

I believe you said you're working on a dual DCNF setup for the X1/9? As you know they have linkage attached to the valve cover (cam box lid); primarily a long pivoting extension from where the pedal's flex cable ends on the driver's (left) side, over to the passenger's (right) side where it then extends to the carb/fuel injection butterfly. Some are completely rigid rods (i.e. the carb applications) and others have a short flex cable section between the pivoting rod and the intake (i.e. fuel injection). See pictures below.

It might be easier to start with the FI type valve cover so you have the fittings for a cable on each end of the pivot, although that short cable has a unusual fitting on this end - more like that of a rigid link's. However I recall that with dual carbs the linkage needs to be more in the midline area rather than toward the right side. So you might want to modify the long pivoting extension so it aligns with the center of the two carbs. If you do that then you can make any type of fitting you want on that area of the pivoting rod. That's were some of the parts pictured in the above links will help. A "clamp-on" lever could be added anywhere along the middle of the pivoting rod to align with the linkage between the carbs...something like this:
99006.251-2.jpg

A ball stud can be added to the end of this lever for attaching a rigid rod to the carbs' linkage:
700.123-2.jpg

If you prefer a flex cable link instead of a rigid rod connecting to the carbs' linkage, then the lever will need a fitting like this on the end (to mount the cylinder that holds the end of the cable):
45048.007-2.jpg


For a carb swap I did (single Weber DCNF on a stock manifold), I eliminated all of the pivoting linkage from the stock X1/9 valve cover and went completely flex cable all the way to the carb. To do this I switched the valve cover with one from a 128 that has no pivoting rod attachments. Then I extended the X's flex cable from the pedal to allow it to reach around toward the rear of the engine bay - where the new carb linkage was located. Something like this may be easier than modifying the stock linkage?

Images of X1/9 valve covers and linkage; various carb and FI versions:
21644.jpg
21644_2_.jpg
21646.jpg
 
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I use the original 74 cam box cover with an added lever similar to what Dr. Jeff showed. A threaded shaft with Nylon fittings is used to connect the lever to the Weber interlink fitting:

1974 Fiat X19 Dual 40 DCNF Linkage Closeup -Top View.jpg
 
Thank you guys, exactly I want to made something similar or same as on photo up, that is plug and play with all DCNFs.

Yes Carl you are right, but dont remember if all 128 or just SC model? But we have Zastava cars 101 and 128 models which are based in Fiat 128, any they use classic throttle cable system which alow on side to connect cable.
But Fiat 128 on multirod throttle also think will be possible to connect on similar linkage.
I remember Alquati kits use different method, like steel bar on manifold then each carburetor have different linkage connection...
 
I've seen various arrangements; some use all steel rod linkage, some flex cables...all have slight advantages and disadvantages, but all work. The little fittings on the ends of either type (solid or flex) can be changed, or the fitting on the carb linkage changed, to match everything. For example there are flex cables with the same fitting connection as typical steel rods use, and there are steel rods that have fittings like typical flex cables use, and there are carb attachments for either. So you could make it whatever way is easiest for what your applications use, or what parts are available to you. If these are being made to sell to X1/9 owners then it is best to make your linkage fit the stock Fiat parts - like you said. So the lever you make (like the top picture) could have whatever type of connection on the end that matches the Weber carb linkages you also sell. Hope all of that made sense, I'm sure it is what you already are thinking. ;)

I believe all of the stock X1/9 linkages on the cam box bover are the same diameter of shaft (maybe someone can verify this, I only have two of the types to compare and they are the same). So if the lever you make (top picture) fits that diameter shaft (pivot extension on valve cover), then it should work for any X1/9. It just needs to be clamped in the right spot along that pivot shaft to align with the carb linkage. The rest of the car's throttle cable and linkage do not have to be changed. This means it is pretty much a universal fit for all X1/9s.
 
I think the odds of having the carbs staying in sync with each other would be better with an interlink setup rather than two separate linkages.
 
dllubin said:
I think the odds of having the carbs staying in sync with each other would be better with an interlink setup rather than two separate linkages.
Click to expand...

If you use separate linkages the quality of parts seems to be the difference in keeping the carbs in sync. Poor quality bearings and other parts will have you constantly adjusting the linkage and never being able to get it right. It's probably the same with interlock systems, just not as many connections to go wrong.
 
dllubin said:
better with an interlink setup
Click to expand...
Agreed. I sort of assumed that was the intended setup; something kind of like this in between the two carbs to allow sync of them:
45041.270-2.jpg


My thought was to have one lever off the stock pivot shaft (valve cover), a linkage (either solid rod or flex cable) from that lever to a link/fitting on one of the carbs, and this interlink connecting the two carbs. I'm not sure what's available, but it would be nice if the link/fitting that activates the throttles could be located in the same area as the interlink, centerline of the whole setup in between the carbs. That would reduce the 'torque' along the throttle shafts/interlink.
 
gene cooley said:
If you use separate linkages the quality of parts seems to be the difference in keeping the carbs in sync. Poor quality bearings and other parts will have you constantly adjusting the linkage and never being able to get it right. It's probably the same with interlock systems, just not as many connections to go wrong.
Click to expand...
Yeah, that's the point - less connections, less tolerances to stack up. I've actually had pretty good luck with the interlink setup. Last year, I removed the intake manifold with dual DCNFs from my 1300 that self destructed in 1995, and stuck it on a 1500. When I went to balance the carbs, they were still in balance despite being on a different engine and not being balanced since the 80s.
 
Dr.Jeff said:
Agreed. I sort of assumed that was the intended setup; something kind of like this in between the two carbs to allow sync of them:
View attachment 27442

My thought was to have one lever off the stock pivot shaft (valve cover), a linkage (either solid rod or flex cable) from that lever to a link/fitting on one of the carbs, and this interlink connecting the two carbs. I'm not sure what's available, but it would be nice if the link/fitting that activates the throttles could be located in the same area as the interlink, centerline of the whole setup in between the carbs. That would reduce the 'torque' along the throttle shafts/interlink.
Click to expand...
Here is a closeup of the Weber interlink parts circa 1980:

Dual 40 DCNF Interlink.jpg


It came with the ball fitting for the linkage on the interlink when I bought the carbs and manifold from Joe Serra. I agree that connecting the linkage between the carbs is likely to have a better outcome due to the issues you mentioned. That horizontal rod across the center of the photo is my home made cold-start "interlink". It is just a welding rod cut to length but works just fine with the factory choke cable.
 
dllubin said:
It came with the ball fitting for the linkage on the interlink
Click to expand...
Thanks for the pic - that's exactly what I was trying to describe, with the linkage being pulled from the middle between the carbs (red circle) instead of from one far end of one of the carbs (as I have seen done in some cases).

Dual 40 DCNF Interlink.jpg
 
It might be difficult to take advantage of the cam box cover linkage assembly if linking to the outer sides of the carbs. The only reason I can think of doing it that way is that to the casual observer, it is not obvious how to fit a link through that mess in the middle. There is actually more room than it looks, and if you bend the linkage rod in the right spot it has plenty of clearance.
 
Love these close up pics guys..I have twin DCNF 40s I believe, that are not stock to my 71 Sport Coupe..where the two carbs synch together, it just doesnt look exactly like any pics or diagrams I see..and looks like a homemade arm may have been welded on to connect the carbs..I will upload a pic or two and would certainly appreciate anyone advising me on how to make it more correct, and maybe what to purchase..or any feedback on what the hell I have, like maybe certain linkage arms may have been mixed and matched to fit? I could leave it alone, but during a rebuilding process, id like to go the extra mile and correct any hack work from the previous owner. I will be removing the carbs shortly and will have better views..Thank you all.
IMG_0788[11662].jpg
IMG_0789[11663].jpg
IMG_0795[11669].jpg
 
italianfrank said:
Love these close up pics guys..I have twin DCNF 40s I believe, that are not stock to my 71 Sport Coupe..where the two carbs synch together, it just doesnt look exactly like any pics or diagrams I see..and looks like a homemade arm may have been welded on to connect the carbs..I will upload a pic or two and would certainly appreciate anyone advising me on how to make it more correct, and maybe what to purchase..or any feedback on what the hell I have, like maybe certain linkage arms may have been mixed and matched to fit? I could leave it alone, but during a rebuilding process, id like to go the extra mile and correct any hack work from the previous owner. I will be removing the carbs shortly and will have better views..Thank you all.View attachment 83357View attachment 83358View attachment 83359
Click to expand...
Yes there are some added welds visible. In your last photo I would look to bend that tab so ti better interfaces between the screw and the stop as there isn’t much contact there at the moment.
 
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