Six pack questions.

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68barracuda

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I'm thinking about installing a six pack set up with mechanical secondary carbs cars to my 68 barracuda.
The motor is a 360 30 over align honed parrell decked with Ross forged flat tops J heads mild port work and 2.02 1.60 v1 piece SS valves and heaver double springs, Cloys double roller and comp cams 484 292 cam hyd . She is at 10-1 compression and screams with the 850 set up that is on her now but that six pack set up sure would look nice under my hood.
But is it going to be a pain to set up? It does not have the Vac pods for the outboards so it would seem set up should be easyer.
anyone have any input?
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I saw this post over at MoParts where you got some good information, some of which I'll repeat here.

Those appear to be Chevy carbs due to the fuel inlet is on the drivers side. No vacumn secondary means a brutal transition from fast to hang on for dear life. And those air cleaners: unless you plan on sawing a hole in your hood....forget `em. I lusted over those air cleaners for MONTHS. Bought a set... and they don't fit under the hood. Even with the shorter air filter elements.

Barracuda163-vi.jpg



Here you can look across the tops of my fenders and see how high they really are.
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That's why I'm back to the stock air cleaner, which fits very nicely thank you!
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But aside from the performance rush, nothing sez "LOOK at THAT!" more than multiple carbs. 8)
 
Hey John, ProMax makes new base plates for the 6pak. Would you (Or anybody else here) know if they'll work on the Chevy carbs?
 
I don`t think it would be a good fit without the vacuum secondaries,especially on the street. The mechanical set-up would work well for race applications (WOT) with a large displacement engine or a well worked small block. All in on the three carbs is around 1350 cfm, the rest of the engine needs to be able to handle it.
 
68barracuda said:
I'm thinking about installing a six pack set up with mechanical secondary carbs cars to my 68 barracuda.
The motor is a 360 30 over align honed parrell decked with Ross forged flat tops J heads mild port work and 2.02 1.60 v1 piece SS valves and heaver double springs, Cloys double roller and comp cams 484 292 cam hyd . She is at 10-1 compression and screams with the 850 set up that is on her now but that six pack set up sure would look nice under my hood.
But is it going to be a pain to set up? It does not have the Vac pods for the outboards so it would seem set up should be easyer.
anyone have any input?
4295729-PICT0904-1.JPG
Click to expand...

Ya' they look nice and pretty,but can be an absolute pain to tune and run properly,and won't touch a properly tuned 4 barrell performance carb.
 
Just like a properly tuned 4 Bbl. a properly set-up 6 Bbl. can be made to work very nicely. I hadn't yet installed the front carb's vacumn pot.
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I don't know if the ProMax pieces will work on the GM version of the Holleys. I know the carb's will physcially bolt onto the Mopar manifold, but as for the butterfly openings I wouldn't know.
 
I thought this was a thread about beer.
 
I have an older factory sixpack setup. It runs great. It was on the motor when I purchased the car. I don't have specs for my engine, it's a 340 with a hot cam.

John has pointed out idle quality might be a problem. It's tough to get at the front & rear carb idle adjustments. The Promax?? carburetor baseplates he mentioned would be the ticket.

Kickdown linkage rods are hard to find. I got a Bouchillon cable for the kickdown.
 
I`ve had 3 cars with 6 barrel induction and I`ve never had the tuning problems that so many people have referred to. The secondaries work just like a 4 barrel but instead of two there are four. There`s the initial set-up and then you dial it in and leave it alone. Too many people have to constantly screw with their carburetors long after the carbs have been tuned to their optimum potential. The key is to tune it and forget it. The 6 barrel system has always worked great for me on big blocks. I`ve never tried it on a small block but I`d highly recommend the set-up for a big block street car.
 
I haven't had mine long enough to monkey with it, but it runs good, has an idle like a 2 bbl should and kicks in hard. It does need some tuning, and the carbs are due for a rebuild and tune so maybe I'll have an different opinion afterwards.
 
Longgone said:
I`ve read that article. I think a portion of it comes directly from the old DC catalog. Excellent info in there. Thanks!
Click to expand...

I remember it from an old thread that was here.

The seven pages that are under the red heading (U.S. Carbs), are the best info to go by. The rest of the of the article advocates too many changes to be made to the carburetors IMHO.
 
If anyone is interested, I have a new factory six-pack fuel line set for sale.

Picture 664.jpg
 
Longgone said:
I don`t think it would be a good fit without the vacuum secondaries,especially on the street. The mechanical set-up would work well for race applications (WOT) with a large displacement engine or a well worked small block. All in on the three carbs is around 1350 cfm, the rest of the engine needs to be able to handle it.
Click to expand...


from everything ive read i would have to agree. you would be better off with vacuum outboards on the street.
 
340srule said:
Ya' they look nice and pretty,but can be an absolute pain to tune and run properly,and won't touch a properly tuned 4 barrell performance carb.
Click to expand...

Just wondering, have you ever run a 6 bbl. system?
 
340srule said:
Ya' they look nice and pretty,but can be an absolute pain to tune and run properly,and won't touch a properly tuned 4 barrell performance carb.
Click to expand...


I beg to differ.. My dad has a Challenger T/A..stock and WOW! the vac secondary allows the motor to keep up with the carbs but when it wide open..hang on!!! exc. set-up if working correctly
 
Something I've always wondered, do six-packs give a noticeable difference in performance over a normal 4-barrel? It seems as though they flow about the same, wouldn't the point of a six-pack be to allow more airflow because there are 2 extra venturis that can be smaller overall, improving fuel atomization?
 
340srule said:
Ya' they look nice and pretty,but can be an absolute pain to tune and run properly,and won't touch a properly tuned 4 barrell performance carb.
Click to expand...

I`ve had as much or more trouble with 4 barrel carbs as I`ve had with any of my 3 x 2 set-ups. These 6 barrel systems are among the best systems for RB engines, bar none. If you get an opportunity, check out the old Direct Connection racing manual, there`s a good section devoted to the six barrel.
 
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