Super Six install on 1974 Dart

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rich006 said:
I thought I needed to replace the bracket on the end of the kickdown linkage, because I'd been told that the D is oriented differently on the Super Six. However, the bracket original to my Dart is the same as the one that came from the donor 1979 Lebaron.View attachment 1715627162
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are you certain the two are the same?
i think more importantly the the position of the D shaped hole, is the distance between it, and the hole where the kickdown linkage actually attaches

this determines the ratio of the kickdown



as for the colder intake, i would see if an airhat from a dakota would fit on the 2 barrel

if it does, that would be my starting point
(one of these)
i betcha they practically give them away at the local junkyard



103154d1501410018-5-9l-5-2l-3-9l-and-4-7l-custom-ram-air-diy-100_2844.jpg
 
diymirage said:
are you certain the two are the same?
i think more importantly the the position of the D shaped hole, is the distance between it, and the hole where the kickdown linkage actually attaches

this determines the ratio of the kickdown



as for the colder intake, i would see if an airhat from a dakota would fit on the 2 barrel
Click to expand...

I see what you're saying, but I think the two are identical. Thanks for the tip on the Dakota part.
 
After connecting the kickdown linkage, I realized it was bent at the top end, which must have happened when it was removed from the donor car or while it was dangling later.
IMG_3485.JPG
 
I got the kickdown rod end straightened out and reinstalled. The throttle cable is a bit too long for the new setup. It's connected, but it's bent into a sort of S. Now that I look at the Super Six article on slantsix.org I see the throttle cable is one of the items needed for the conversion. Would an F-body throttle cable be the right length?

Also, the choke thermostat rod is way too long. I guess that's partly because I used the thin gasket that came with the carburetor, but it seems like even with a thick gasket it would still be too long. Not sure what to do about that.
IMG_3487.JPG
IMG_3488.JPG
 
rich006 said:
Also, the choke thermostat rod is way too long. I guess that's partly because I used the thin gasket that came with the carburetor, but it seems like even with a thick gasket it would still be too long. Not sure what to do about that.
View attachment 1715628168 View attachment 1715628172
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Come on man, its literally a rod with two hooks on it
You could have made one from an old clothes hanger in the time it took you to post about it
 
diymirage said:
Come on man, its literally a rod with two hooks on it
You could have made one from an old clothes hanger in the time it took you to post about it
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LOL, I like to overthink things. After looking again I think it was just because of the thin gasket. I'm getting a thicker gasket instead of shortening the rod.

Any ideas about the throttle cable? How much bend is too much bend? My intuition is that the 1bbl cable is too bent when connected to the 2bbl linkage. I can probably get the throttle cable from the donor car if it will be a good fit.
 
Glad to see your working this out

That throttle cable does look a bit bendy
I would measure it and see how much too long it is, then post a want add for one

You can always get aftermarket cut to fit cables, but quite frankly, the older ones are better quality
 
The choke rod is not too long. You are supposed to bend the rod to adjust the choke. Put a simple S bend in it by grabbing it with a pair of pliers and twisting. From there, you can "back off" the S bend as necessary to get the correct length. That's how it's designed.
 
This is the first I've seen of this thread and damn...is there ANYTHING the Chicoms won't copy?
 
Charrlie_S said:
Democracy
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They copied that too. It's just fucked up and doesn't work like the original, just like everything else they make.

"We like leader (don't kill me). He great, just like Trump (don't kill me)."
 
jos51700 said:
is there ANYTHING the Chicoms won't copy?
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I personally am grateful that some Chinese entrepreneur is hustling to make a buck, the good old American way. If not, nobody would be making the parts I needed. I have no illusions about their government being decent or acceptable.
 
Got it running! Idle was pretty rough at first, but with my AFR gauge it was very easy to see that it was on the rich side. Of course I probably could have also looked at the black spot forming on the driveway under the tailpipe. :)

The first time I stepped on the gas pedal, the car jumped so fast I almost drove off the driveway into the grass. What a difference! One thing that makes it feel livelier is the throttle return spring is a good bit lighter than what I was used to, but the engine is definitely making more torque now as well.

It still pings in high-load situations (vacuum below about 5 inches, RPM above about 2500), and the AFR shows lean in those conditions (16-17 going uphill on the highway), so that problem isn't solved. But the Super Six is definitely a major improvement over the 1945. Now I just need to dig into the BBD adjustments to figure out how to enrich the mixture at speed.

Other issues:
- The choke heater doesn't seem to be connecting to the terminal that powers it. The connector is very loose and the choke seems to stay closed longer than it needs to.
- The throttle cable is about 6" too long at 24" end to end. Thanks to FABO user RPMagoo for agreeing to sell me an 18.5" cable for a reasonable price.
- The air cleaner touches the underhood insulation. I might need to shorten that choke control rod after all, so I can use a thinner carburetor gasket. Right now I have a 9/32" gasket, plus two thin gaskets that came with the carb.
- The heated air inlet door (in the air cleaner horn) didn't seem to be closing, even though I think it should if the ambient temperature is under 100 degrees. Need to troubleshoot that.
 
rich006 said:
I personally am grateful that some Chinese entrepreneur is hustling to make a buck, the good old American way. If not, nobody would be making the parts I needed. I have no illusions about their government being decent or acceptable.
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I hope I'm very, very wrong in my suspicions that those hustling Chinese dollars are funding attacks against us. Some turn signal switches or AMD panels aren't worth that to me, personally.
 
jos51700 said:
I hope I'm very, very wrong in my suspicions that those hustling Chinese dollars are funding attacks against us. Some turn signal switches or AMD panels aren't worth that to me, personally.
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It's a valid concern, but at the same time you can't untangle everything. I know the North Korean government has all kinds of schemes to make money, including selling drugs and weapons (not to mention simply printing fake dollars). I don't think the Chinese government is doing the same with carburetors, turn signal switches, and sheet metal. I imagine a small-ish company making these things, just like you would still have in the US if they had lower labor and operating costs. Most likely these companies don't even pay their taxes to the Chinese government, if they can get away with it. :)

The way I see it, by helping regular Chinese people make a good living, I'm reducing the chances that they will support a government that might want to attack us. Not that I wouldn't happily buy American...

There, now this thread is officially off the rails.
 
rich006 said:
The way I see it, by helping regular Chinese people make a good living, I'm reducing the chances that they will support a government that might want to attack us.
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That's funny. We should take this to PM's. Agreed: Apologies for thread derailment. Carry on!!
 
rich006 said:
Now I just need to dig into the BBD adjustments to figure out how to enrich the mixture at speed.
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I don't get how the BBD stepup piston is supposed to work. Vacuum holds it down and a spring pushes it up when vacuum is low, but there are plastic tabs on the accelerator pump rod that force it to move up at down according to throttle position. So how can the vacuum and spring control anything if it's seemingly slaved to the throttle? Or do the tabs give it enough wiggle room to allow vacuum and spring to control it within a small range?

I adjusted the stepup piston screw. I believe that adjustment caused it to run richer at speed now (AFR is about 12-13 at part throttle). However, now it's also rich at idle even with the idle mixture screws all the way in. I also had to back the idle speed screw all the way off to make it idle low enough.

Also, I have a couple of vacuum lines capped off, and the caps blow off when I shut down the engine. Also the engine diesels sometimes after shutdown.

Any ideas welcome!
 
If the metering Rod spring it's too soft or too short it may never reach the rich limit piston stop. Carter used several different Step Up Springs depending on model and weight class, definitely a tunable part Timing chain? - Slant Six Forum
 
OK, I understand the plastic rocker arms on the accelerator linkage have some wiggle room so that the stepup piston (and metering rods) can move up and down a bit at any throttle position.

I took out the stepup piston assembly and I saw that the gap that is adjusted by the screw on top was zero. It took several clockwise turns to open up a gap to 0.030". Now the AFR is about 13-14 at part to full throttle.

Not surprisingly, the idle is still too rich. Idle RPM is high even with the screw backed off completely and the mixture screws all the way in.

On another topic, I installed the 18" throttle cable and it fits pretty nicely.
 
Update for anyone interested...

The Chinese BBD clone was running rich at idle (even with screws all the way in) and going very lean with the throttle open. I spent a lot of time adjusting the stepup piston, trying to get the fuel/air mixture rich enough at high speed/load while also lean enough at low speed/idle. I never could get it right. Finally I bought a remanufactured BBD labeled for 1978-1979 Slant use. It runs like a dream. I can adjust the idle mixture to 13 or 14 AFR, and then at WOT it runs around 13. I got the reman carb from United Automotive Remanfacturing.
 
rich006 said:
Update for anyone interested...

The Chinese BBD clone was running rich at idle (even with screws all the way in) and going very lean with the throttle open. I spent a lot of time adjusting the stepup piston, trying to get the fuel/air mixture rich enough at high speed/load while also lean enough at low speed/idle. I never could get it right. Finally I bought a remanufactured BBD labeled for 1978-1979 Slant use. It runs like a dream. I can adjust the idle mixture to 13 or 14 AFR, and then at WOT it runs around 13. I got the reman carb from United Automotive Remanfacturing.
Click to expand...

Great thread, really glad to hear you got the carb issu solved. Did all the pinging also go away?
 
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