6-bbl v. 8-bbl

Technical Question and Answer - On topic to 71-74 Plymouth B-bodies only.

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BigBlock
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6-bbl v. 8-bbl

Post by BigBlock » Thu Dec 02, 2010 10:32 pm

Just wanting everyone's input...Any thoughts on 6-bbl v. 8-bbl? I am deciding which setup to run. Performance is my main thought, but I know Barry Grand has a cool 6-bbl setup. Anyone have personal experiences I can pull from?

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Re: 6-bbl v. 8-bbl

Post by ILUV72RRs » Thu Dec 02, 2010 11:52 pm

Maybe 6 Packs have improved. But 10 years ago, or so. When Dick Landy was still alive. He built an engine for my friend's '70 Challenger RT/SE. Dick told my friend at the time he could of got more horsepower out of it if he had used just a single 4 BBL. But my friend wanted the 6-Pack on the car for the looks and attention you get at car shows. As I'm sure that some of the 4 BBL intakes may work better than the 6 Pack intake.

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Re: 6-bbl v. 8-bbl

Post by BigBlock » Fri Dec 03, 2010 2:08 am

So you would say the single larger 4 bbl vs 2 smaller 4 bbls?

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Re: 6-bbl v. 8-bbl

Post by 72Satellite440 » Fri Dec 03, 2010 3:18 am

I vote on one large 4 brl also- I got a indy alum intake - 850 cfm
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Re: 6-bbl v. 8-bbl

Post by 72RDRNR » Fri Dec 03, 2010 8:49 am

Not sure of what you have but for the motor I am building (stroked 400 to 470 - 600ish HP)I was told that a 2x4 set up would be around 50-75 HP less than a good single 4bbl. The intakes for the 400 2x4 set up are the cause for this. Not sure how the 6bbl set up compares.

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Re: 6-bbl v. 8-bbl

Post by ILUV72RRs » Fri Dec 03, 2010 4:38 pm

Multiple carbs always look impressive. No question of that. But a single carb seems to give the best performance. Also less to wear out, and less possible leaks to deal with, and easier to tune.

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Re: 6-bbl v. 8-bbl

Post by BigBlock » Fri Dec 03, 2010 7:50 pm

So you think it is due to intake design not the fuel delivery itself that the 2 x 4bbl setup would yield less hp? I would think that more gas = more power, but it sounds like the consensus is a "NO"

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Re: 6-bbl v. 8-bbl

Post by ILUV72RRs » Fri Dec 03, 2010 10:41 pm

I would venture to say that the reason a single carb works better is because it gets more air to mix in with the gas. Which generally are directed to the ports with longer runners. With multi carbs your runners usually aren't as long. Trying to cram as much gas into the chamber doesn't mean that the car is going to run faster. Plus again, bear in mind that you only have to tune one carb. Easier to do, and if something goes bad. It's easier and cheaper to fix one carb. If cramping as much gas into the intake was really that great. Then tunnel ram manifolds would still be the hot ticket. As that's basically what they were. I get the impression from your questions that your dying in hopes that someone comes on here, and says multi carbs are the fast way to go. Because that's what you REALLY want visible on your car's engine. Or you have a chance to buy a multi carb intake and carbs at a good price. Hey, it's your car - go for it!

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Re: 6-bbl v. 8-bbl

Post by sogtx » Wed Dec 08, 2010 11:49 pm

Unless you have a hemi ( would look correct for two carbs ) a Six Pack tuned correctly is superior
You can get economy and performance
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Re: 6-bbl v. 8-bbl

Post by Eric » Thu Dec 09, 2010 1:35 pm

sogtx wrote:Unless you have a hemi ( would look correct for two carbs ) a Six Pack tuned correctly is superior
You can get economy and performance
I was thinking the same thing
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Re: 6-bbl v. 8-bbl

Post by bruce » Thu Dec 09, 2010 2:02 pm

Dave always like to tweak on me that 6 barrels is two too few, but for me 6 barrels is JUST right... Nothing in the world cooler than a multi-carbed Mopar! :D
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Re: 6-bbl v. 8-bbl

Post by ILUV72RRs » Thu Dec 09, 2010 7:39 pm

Agreed, a 6-Pack definitely looks much better on a Mopar than a Chevy. However, you have to be willing to tune them. As I knew lots of owners back then who had 6 Pack/ 6BBL cars that didn't run good because they were always getting out of tune, and going back to the dealerships for a tune up. The '69 cars especially. As a good friend once put it: "Those only run good two ways. One with your foot all the way in it. Or with the key off. They just don't like to just putt around town." At least the '70 & later carbs were better for on the street. If you're into all out performance. Then you're going to constantly tune your car, and be on top of it anyway. If you're just going to get in, and drive it without keeping on top of it. Then chances are you will be beat.

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Re: 6-bbl v. 8-bbl

Post by BigBlock » Thu Dec 09, 2010 11:16 pm

Thanks for the input. I am toying around with how I want to build my 440. This is why I am asking. On that same topic, I am curious if anyone has any pics of a 71-72 bird with a supercharger punched through the hood? I've always wondered what that would look like. I am tempted to do it, but I couldn't go through the air grabber. It just seems wrong in every way. :o

I have always wanted a supercharged ride, but I LOVE the air grabber. I wanted to see what one looked like before I took the plunge. Thanks for any input!

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Re: 6-bbl v. 8-bbl

Post by bruce » Fri Dec 10, 2010 10:03 am

BigBlock wrote: On that same topic, I am curious if anyone has any pics of a 71-72 bird with a supercharger punched through the hood? I've always wondered what that would look like. I am tempted to do it, but I couldn't go through the air grabber. It just seems wrong in every way. :o

This one was posted on Moparts...
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Re: 6-bbl v. 8-bbl

Post by 72Satellite440 » Fri Dec 10, 2010 11:08 am

Looks awsome

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