Mechanical linkage on Vacuum carbs..

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MAPS

MAPS

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I'm just curious, would it be possible to set up your six pack set up that are original vacuum operated secondaries with the mechanical linkages instead ?
Can you just remove the vacuum pods and swap the stock linkages for the mechanical ones ? Would you need to do anything else in particular or would it be able to run just like that ?

I know that if anyone can answer these questions they are on this site.
Therefore a thank you is in order in advance.

Regards,
MAPS
 
I would think it would create a killer bog as there are no accelerator pumps on the vac sec carbs. removing the pods probably isn't a good idea as thats what holds the outboard carbs closed when not in use. Just my thought
 
Talk about a bog! Guys used toput a bolt in the linkage on 4 barrels. The outcome wasn't good.
 
Not going to work well. Leave them vacuum operated. If you want mechanical carbs you need outboards with shooters.

why do you feel the need to make them mechanical? I ran high 10’s on a vacuum operated six pack on my street car.
 
Vacuum secondary carbs aren't made to be mechanical. They are metered different. No reason to re-invent the wheel.
 
slickchick said:
removing the pods probably isn't a good idea as thats what holds the outboard carbs closed when not in use. Just my thought
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This is an incomplete statement / idea. Yes the vacuum pods have a spring and they keep them closed. But once they are opened up the mechanical linkage closes them when you lift your foot off the gas pedal. If the linkage was missing you would be crashing the car.

you can’t make them mechanical because the outboards don’t have an acceletator pump. The mechanical carbs you buy have accelerator pumps on all 3 carbs.
 
Oh it worked so terrible, they used to make kits to do it. Puuuulllleeeezzzeeee they've been doin that for decades. Tons of racers have done it with no bog no time no how. Now, don't ask me how, cause I don't know that part. lol I think even Mopar Performance made a mechanical kit at one time.
 
RustyRatRod said:
Here it is. This is what Direct Connection used to offer. There were also other companies that offered other ways to do it besides the mechanical carburetors/conversions. I knew I remembered it.

Old Direct Connection 340/440 Six Pack Mechanical Carbs
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those have pumps, I have a set. Different animal than converted vacuum carbs.

B2C8BBA1-D313-4840-8E44-A2FE17750012.jpeg
 
68 HEMI GTS said:
those have pumps, I have a set. Different animal than converted vacuum carbs.

View attachment 1715703311
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No ****. I'm only blind out of one eye. There were other kits available like I SAID that made the conversion from vacuum to mechanical happen. That was the only example I could find quickly. If someone has an older MP or Direct Connection book, I believe it will be in there. I cannot remember if it was them, or someone in the aftermarket that offered the vacuum conversion, but someone did and it worked pretty good.
 
I never liked the split second disconnected/delayed reaction upon opening and closing that the vacuum secondaries have. Mind you, I'm not talking about a bog that can be felt from the vacuum carbs not being set up right. There is a short but measurable delay from gas pedal input while waiting for the vacuum set-up to either open AND close. I guess people get used to it, but I never liked it.

I just like the instantaneous response that the mechanical carbs offer over the factory units. They are very easy to tune too. You do have to be cognizant while driving them as you can mash them wide open from idle, which is not usually a good way to use them. I have always run the Direct Connection Hustle stuff mechanical 2300 Holley carbs. I've been running those for over 4 decades.

Having a wide band to tune the mechanical carbs makes dialing them in easier than ever.

20200427_174153 (Medium).jpg


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Linkage2 (Medium).JPG
 
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RRR
That's exactly what I was trying to decipher, because in the 80s I had a 440 6 bbl car that It's original carbs were switched to mechanical linkages and I almost can guarantee that it was done with some "kit conversion" I just did not recall the exact nature of it.
I knew that if anyone would know the ins and outs of it they would be from this site.

Again, thank you for everyone's response, thus far.

As for the bogging, I remember that there were 2 sliding locking type bolts on the linkage arms that allowed you to control when the middle carb could open completely....as well as the outer carbs.
In fact there was a lot of trial and error involved until you got it to where you knew it was as good as it can get with your set up, rear gears, HP of your car etc.
You were are able to have the car start on all six barrels if you wanted to but that was too much for my car at that time.
If the car was able to hook and go off the line (and with a bottle at the time, which NOS had made their 1st the six pack set ever...for me, and I was in Canada, A Mr Thermos I recall was the man's name) the car did not bog as it came alive when everything was tuned in properly.

Thanks again everyone.
MAPS
 
My 6-Pack doesn't bog with vac pods. I would have to be really bored and want to spend a lot of time, money and frustration to ever want to switch over to mechanical.
I have gone through enough just trying to get my set up right, and I am not quite there yet, but very close. Not all help on how to tune a 6-Pack was helpful, it was a starting point.
 
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