When you get on it fast, it should be a "major" boost!!!
Even stock, mine was a huge "kick" in the aZZ when the end carbs come in. If you're not getting that, then there is something with the end spring rate, something sticking, or in one instance I saw recently....the base gaskets on the end carbs were put on backwards...which stops the throttle plates from opening!!!
Tom Quad just posted some guidelines...from my own experience, he's bang on ...except watch that fuel level in the end carbs.....trickling out the sight plug may be a little high. Mine will flood slightly when set like that. But every set up will be a bit different, so start tunin'

There is no typical RPM they open at, and, as said, you will not get them to open with your head leaning in over the fender.

Yes they do...


I dont understand that comment, mine do just with blipping the throttle 7k plus, no problem, no bog with or without spray..and still easy to drive, but im only concerned about one thing WOT.

This is bumping the 7k chip it likes the 7600 chip.

http://www.youtube.com/watch?v=--GfJyk_GaA

The end carbs will NOT open without a load on the engine.

yes they can.. 7k off idle bump, no issues

The end carbs will NOT open without a load on the engine. Umm mine do


http://www.youtube.com/watch?v=S0FlEqfesF8

I guess it depends what your looking to do

I need a new tip in my wideband...

Alot of good OLD info, I would hate to see a youngster continue in this line of thinking that there are limits and impossible goals when working with six pack carbs when certain goals are easily obtainable.

I clearly can debunk 3 (posted vids of two of them) of the old school "YOU CANT DO THIS" ways of thinking.

No dis. meant to anyone who posted but advancements and progress dont get made on old tech, but its a good start, things progress and if more out of the box thinking was done vs copy and paste articles maybe some of the old myths could be put to rest.

....I remember Goody talking about reving up his cuda at a red light and bending some stuff that should'nt be bent....I dont think he'll be caught doing that again.. ... I've seen alot of posts where guys with stock or close to it engines claim the 6-bbl wont open when the throttle is free reved....Especially a SB....A stroker or modified engine is an apples to oranges comparison on how the 6 pack will operate...Get the car out on the road under a load and stab the throttle then see what happens...If it doe'snt set you back in the seat something needs attention..

Not everyone is like you to free spin their engine to 7k plus without a load on it , ask the youngsters that did it and bent valves ...



Yep, true, However im far from a youngster, but far from old.

Use good parts and check and recheck on assembly. Build to your needs, I do and have no issues.

But as far as the six packs go, I see nothing set in stone on how far you can take them and to propagate old info does not help in the progression of six pack systems but just adds fodder to the brand X mags who say they are old, out dated and fall short of certain performance standards.

No disrespect meant to any of the posters, most are far smarter then me....I just look at things differently and know what has worked for me.

Its good to see there is still so much love for the six pack systems that so many are willing to deal with the small quirks involved with running them

The six pack set up can definitely be finicky....especially with using them on a all-out stroker like I did. Constant tuning etc until I got it right (well..at least right in my opinion!) Done right, Six Packs rock!
They CAN be tuned....not like the wife...which NO amount of TUNING seems to have any effect!!

The car is doing pretty good but stumbles on acceleration could this be do to wron pump cam?

it starts off good if i pump the gas a bit

it should sound like this

http://www.youtube.com/watch?v=kxm-NTSOc1s&feature=related

I think the "theory of operation" needs to be reviewed

A six pak engine runs on the center carb and idles on all 3. The center carb is 450 cfm which means it has plenty of flow up till about 4000 rpm where the secondaries come in and take care of the work. The idles circuit in the outboards is always contributing air and fuel to the mix.

The center carb needs to be set up properly first and then the secondaries dialed in.
Whacking the throttle at idle to get the secondaries to open is pointless and useless as it indicates nothing other than a lack of understanding. Black springs in the secondaries is not a misprint, but good advice, if you have not tried the advice I suggest you do.

A properly tuned six pak will out run anything other than a properly tuned heeemi [sic] and then it better had be a stout heeemi as i have beat up more than several of the manly heemis with a six pak over the years.


This is not rocket science and the document provided is culminated from lots of peoples input.
Print the document and go tune your cars and please report back.

im not smashing it out of a idle just trying to go easy and it still stumbles. should i change the acc pump cam?

Does it stumble before it starts to really move? If so, def. take a good look at the accelerator pump. I had to make my own cam on the AAR to get it to come off the line clean. Also I do not agree with the heavy springs in the secondaries. I put the second lightest they make in and tune it from bogging from there. The more air the merrier.

Promax makes some great parts that makes tuning six packs much easier. The ability to put jets in the outboard carbs and to change idle settings on outboards without a trick screwdriver is priceless.

The ProMax billet baseplate for the rear is almost a requirement for any six pack engine with a healthy mix of speed equipment...unless you enjoy pulling the rear one on and off over and over until you get it to idle right. Which spring you use in the outboards will be determined by the car's weight, gear ratio and tranny, but the second lightest is an ideal starting point. Don't forget, it's been said over and over, the outboards were generally lean in stock condition so you'll need to drill the metering plates or add the plates that allow for jets.

Good luck and happy tuning.

Maybe the car needs some other basic tuning like timing adjustments. What is your intial and total timing at? Also is the vacuum line connected to the right port and are they free of cracks? Also the vacuum chambers have small ports where a gasket is used to seal, maybe they are loose or missing, try tightening them.You should look at the diaphragms, maybe they are old or torn. You should definately feel them kick in when you get on it.

I build and tune a lot of six pack engines. Some good info here. What I find most amusing is how people "micromanage" the system. Try to avoid throwing a bunch of parts at it. More often than not, people wind up making the car run worse than if the carbs were left completely alone.

The outboard screws are not a mystery. Takes only a few minutes to dial it in. If you want to use the Promax base, that is fine, however you must properly ream the throttle shaft bore or you will get a hanging of the butterflys. You might not experience it when the engine is cold but as soon as it warms up they tend to bind.

FYI, Ed Cook's six pack A12 car(runs high tens @127MPH on G70 bias @ 3,900#), has carbs that are almost stock. i built the motor and did all the tuning on the car and found NO advantage with some real tricked out carbs. I am still working on the modded carbs, but at this point, the stockers are getting the nod!

MB

Hello Tom Quad,

I've just rebuilt my sixpack and reinstalled -- been off for about past 15 yrs as a "weight saver" (only reason is 60 lbs sixpack vs 30 lbs LD340/750 3310) for my Solo II autocross events (Challenger T/A, hemi-orange/black car). I'm now back into road course "touring/hi-speed lapping" and I've decided to use the sixpack setup again. I'll be the "Official Pace Car" at Elkhart Lk, WIS., Road America track this wknd Aug 14/15... 12 total races to lead the pack! Should be exciting and fun!!!

Car won't run!!! Won't idle; front carb spits lots fuel after shutoff (difficulty adjusting front float); have clear site plugs.

6.5 PV, 64 jets, non-adjsble f/r base plates. 50cc pump.

Where excatly do I hook up the vacuum gage? Any other help? How can I at least get it to run for setting the idle, etc? I want to report good news!!!

Mopar Mitch Lelito
cell 847-682-0807 anytime (Chgo area)

just more info.

http://sixpacksixbbl.homestead.com/mrsixpack.html

Thanks for the extra info.

Last night I worked with a Mopar friend/racer (Greg Bosak) and we got it running, some cracking of exhaust sounds, but still idles too rough. timing is 34 total, 12 btdc w/o vacuum hookup. Vacuum is 13, so the 65 PV should be OK (??). We pulled the plugs and saw they are fouled (64 jets); will put 62 jets in and new plugs/cap/rotor tonight. I do have another 340 center carb (4292) which I may rebuild and see if that makes any difference.

I've got to get it running near perfect as I'm the Pace Car for Elkhart Lk. Road America this wknd!!!. IF the carbs/plugs/cap/rotor doesn't make any difference, I'll have to put back my LD340/Carter 625 Comp Series setup Thursday night/Friday... have to leave early Sat monrng.

Mitch
cell 847-682-0807