Pinch me: I must be dreaming

moparcanuck · Apr 28, 2014

Ever since I installed a Six Pack on my GTX last year, it's been running like a top. Starts like a charm, hot or cold. With the 4BBL, I had all kinds of problems in that department. With the Six Pack, it runs like a dream, fast or slow. Acceleration is crazy. Just won't quit until 5800.

Since I changed the stat to a 160, it runs around 180-190 instead of 210-220. It also stopped burning oil. It runs cooler and much better. All in all, it runs like a dream.

On second thought, don't wake me up.

Mr Belvedere 30144 · Apr 29, 2014

That's awesome! I have a 440 6 barrel in my 65 and it also starts and runs great pulls hard and very strong from 3500 to 5500. I had always heard of issues with these setups but mine is great. I realize it runs on the center 2 barrel unless it is pulling enough vacuum to open the other 2 so maybe that's why it is so dependable.

conv67bdere · Apr 29, 2014

Great news . . . but don't go flying by TOO FAST, nobody will be able to see and appreciate that fine looking ride that you got there ! ! !

Sixpaksteve · Apr 29, 2014

moparcanuck said:
Ever since I installed a Six Pack on my GTX last year, it's been running like a top. Starts like a charm, hot or cold. With the 4BBL, I had all kinds of problems in that department. With the Six Pack, it runs like a dream, fast or slow. Acceleration is crazy. Just won't quit until 5800.

Since I changed the stat to a 160, it runs around 180-190 instead of 210-220. It also stopped burning oil. It runs cooler and much better. All in all, it runs like a dream.

On second thought, don't wake me up.

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Nice looking GTX you have there! I've got the 440/6 in my 1970 'Cuda (F8 green with green interior) and that motor and setup has been just a pleasure for me to own and drive. I had the Holly's rebuilt/restored by a guy who really knew those carbs, and after some minor adjustments when they were first put back on the engine I haven't had to touch them since.

MT_Mopar · Apr 29, 2014

Absolutely love that color! Lets see some pics of the fore-mentioned 6

Hemi Rebel · Apr 29, 2014

Find some wood, and knock on it

Cranky · Apr 29, 2014

Cool! How are the engines built? I know the 6 pack setup can only take so much cam etc before you have to start doing modifications to them and seems to be the biggest problem with original carbs is someone tried to modify them back in the day.

Dennis H · Apr 29, 2014

Nice when everything works. Congrats! Not a 6 pak, but I appreciate when everything is humming along. Cool and no oil usage.

Mr Belvedere 30144 · Apr 29, 2014

Cranky said:
Cool! How are the engines built? I know the 6 pack setup can only take so much cam etc before you have to start doing modifications to them and seems to be the biggest problem with original carbs is someone tried to modify them back in the day.

I don't know why you think this but the 6 barrel set up is no more limited to a certain size cam choice than any other equivalent cfm flow. The 6 barrel set up flows at 1350 cfm, the center being 350 and the outboards being 500. In actual 4 barrel numbers it would equal 900 cfm due to pressure differences in the 2 barrel carbs.
Here is a link to a good read on dyno testing a 830 cfm 4 barrel 440 and a 6 barrel 440. The 6 beat the 4 in HP but lost by just a bit in torque.

http://www.moparmusclemagazine.com/techarticles/engine/mopp_0212_six_pack_system_test/

Cranky · Apr 29, 2014

Mr Belvedere 30144 said:
I don't know why you think this but the 6 barrel set up is no more limited to a certain size cam choice than any other equivalent cfm flow. The 6 barrel set up flows at 1350 cfm, the center being 350 and the outboards being 500. In actual 4 barrel numbers it would equal 900 cfm due to pressure differences in the 2 barrel carbs.

Yup, they flow 1350....but what about the jetting of the outboards? Didn't they come with fixed metering plates? At what point does the engine need 1350? I don't have a lot of experience with the 6 pack setup but do have some with multiple carbs and have run as much as 1500 cfm on modified engines and had to make jet adjustments to dial them in....and since I don't have much experience with them is why I'm asking. Reading info about them is one thing but getting comments from actual users is another.

Mr Belvedere 30144 · Apr 29, 2014

The fixed metering plates can be modified as described in the article with quick fuel metering plates then it's just changing jets from there. The actual CFM comparison would be 900CFM in the 6 in 4 barrel numbers. One benefit is the mileage in the 6 setup running on the center carb most of the time without bringing in the outboards. But in reality who can keep their foot out of the gas on a 6 barrel setup? I cannot. There is nothing like the rush and sound of those outboard carbs kicking in!

440+6 · Apr 29, 2014

First of all they are not 1350 cfm read this:

Here is how you do the conversion between 2bbl and 4bbl carbs

4 bbl carbs are measured at 1.5hg of vacuum and 2 bbls at 3hg of vacuum

To convert from one system to another (with a very small percentage of error) is simple.
Simply use the square root of 2 (1.414).
So to convert a two-barrel rating into a four-barrel rating, divide the two-barrel rating by 1.414.
To convert the four-barrel rating to a two-barrel rating, multiply the four-barrel rating by 1.414.

A six pack setup claims 1350 cfm but it's actually around 955 cfm if you convert to the way 4 barrels are flowed.

Six barrel setups are nothing more than a 4 barrel with an extra set of secondaries that are split into three pieces, and run just as well imo.
I have had a set for over 35 years on my car and drive it regularly weather permitting and they are great.

super-bee_ski · Apr 29, 2014

Great looking car!
Congrads

moparcanuck · Apr 29, 2014

This is the Six Pack setup - or as we Plymouth guys say: Six Barrel. I also installed a mild CompCam for that extra edge and had some custom call outs made for the hood.

Mr Belvedere 30144 · Apr 29, 2014

Thats what I said. They are technically 1350 but About 900 CFM in 4 barrel terms.

Bigal75 · Apr 29, 2014

moparcanuck said:
This is the Six Pack setup - or as we Plymouth guys say: Six Barrel. I also installed a mild CompCam for that extra edge and had some custom call outs made for the hood.

View attachment 184305

View attachment 184307

View attachment 184306

Were you in Orleans maybe a week or so ago - near Orchardview St? Visiting a guy with a Yellow Camaro rsSS? I live right near there and noticed a car exactly like yours. Funny black marks on the pavement too...

moparcanuck · Apr 29, 2014

Yep, that was me. Scott's ok for a Camaro guy. :laughing6:

440+6 · Apr 29, 2014

Mr Belvedere 30144 said:
Thats what I said. They are technically 1350 but About 900 CFM in 4 barrel terms.

Sorry, missed that some how, I'm still amazed how many people think they are 1350 cfm when comparing to a four barrel.

Bigal75 · Apr 29, 2014

moparcanuck said:
Yep, that was me. Scott's ok for a Camaro guy. :laughing6:

Small world. If I ever see you there I'll stop in to Check out your GTX...If you don't mind.

Dad's69RR · Apr 29, 2014

Hey moparcanuck I was wondering what size wheels & tires are on your GTX? I want the same look for my 69RR. Thanks

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