Six pack carb ?'s

-
rumblefish360

rumblefish360

I have escaped the EVIL Empire State!
FABO Gold Member
Joined
Jun 21, 2005
Messages
49,380
Reaction score
23,211
Location
Florida
What is the differance between the s/b and r/b outboard carbs?
 
If I remember correctly, the outboard carbs are the same :-k

Somebody else will chime in if that info is wrong....
 
if im right lol I think the outside carbs are the same, the center one is different can anyone confirm that ?
 
Quick look in the Mopar Engine book (pg. 176) say's...............

"The 340-6Bbl. systems differ from the 440-6Bbl in carburetor distribution so that the carburetors should not be changed from one system to another."

And that's it.

It DOES NOT point out any specifics. I would think the metering plates and spring rate would be the main differences.
 
Center carbs are different on auto and manuals, adding another flavor still.
 
The air bleeds and venturies are different between the carbs, 340 end carbs on a 440 will react faster on initial opening, no matter what springs you have installed vs the same springs on 440 carbs due to orifice/Venturi. Also 340 outboards had fuel distribution tabs on the venturies due to manifold problems
 
They do have different part numbers. Be it from the MP catolog or Holley. I was hoping there was a been there done that person on the board.

I wonder if you could make use of them on a stroked small block? Something greater than the typical strikers we see? Like that 430 cube build. It is only ten incus down in cubes but way up on power vs the 440-6 pack engines they came on.

Any thoughts on that one?
 
EL5DEMON340, Can you tell me about the fuel distribution tabs? And such other things?
 
The fuel distribution tabs are on the 340 outboards only.Looking down the fron the top and from the rear of the carb the tabs are on the right nozzle ring and they point at 2 o'clock.I believe there ia a difference in the auto and manual carbs also but that might just be jetting.In the SIX-PACK ENGINE HANDBOOK they give a setup for a modified 340 and 440 as the same unit with stock intake.Center carb main jet #64,accelrator pump nozzle .031".Front carb main restriction .089",idle restriction .029".Rear carb main restriction .093",idle restriction .029".Yellow springs in outboards.

EDIT:the only thing I see different in the auto and manual is one jet smaller for the manual.
 
MoPar410, I JUST ordered that handbook yesterday!
The only differences in the outboard carbs so far that you have noted are in the distabution tans and jetting?

Primary (center) carbs I am not worried about. Just the outboard carbs.
 
rumblefish360 said:
MoPar410, I JUST ordered that handbook yesterday!
The only differences in the outboard carbs so far that you have noted are in the distabution tans and jetting?

Primary (center) carbs I am not worried about. Just the outboard carbs.
Click to expand...

Yeah that's all.One issue may be if some one drilled out the metering plate hole on the ones you have.And yellow springs for all setups 340 or 440.
The book covers a lot of the 6-pack cars with just a few pages for the actual 6-pack carb set up,that is my only complaint about the book.
 
A bit of advice,unless your doing a factory spec restore you should look into buying the PRO TECH(not sure of the actual name)baseplates.Tuning a 6-pack is a pain when you have to remove the carbs to set them.
 
Well the problem is the SB intake, very restrictive!! im going the same route this summer mopar intake with the 4782/82 direct connection mechanical carbs. If you could find a set they are the hot setup! they flow a true 1150cfm compared to the vacuum at about 975cfm
 

Attachments

  • moto 002 (1280x960).jpg
    81.7 KB · Views: 444
  • 6 pack 003 (800x600).jpg
    60.9 KB · Views: 395
This is my setup: 408 stroker... ported Eddy Performer heads, intake manifold runners were opened (a lot) to match the heads (really flows)...blah-blah-blah.. aaall the hot do-dads we expect. She dyno'd in at a surprising at 543 hp 572 tq, redlines at an easy 7000, shift at 6600 (4-spd car). The pics below were taken while I was still installing the engine, but does show the carbs. As you can see mine is kind of a Frankenstein as the carbs are sacrilegiously from a 427 Vette with mechanical progressive linkage (no vacuum who-ha). That's right, Chebby crap on my PAR... but what can I say, they're awesome. The 6-pack was a pain though, no doubt at all, but once properly set up (dyno), they've provided PLENTY of smiles for quite some time now! But it's weird... these 6-packs: they perform kinda like a 2-stroke dirt bike..ie: Fairly crisp throttle with 'fair' performance (center carb) up to the point where, if I press down a tad more, the linkage will pull both end carbs into the flow and whoa, now we're having FUN! Immediate BIG rush... even when you just wanted a little bit more, you get a LOT like NOW.... which took getting use to (and learning better throttle discipline). You want 6 barrels, just press and there ya go! BUT having run it for a few years now I'm not sure I like it that much anymore. The center carb is smaller than the end carbs (cfm), and with the big stick this engine has, it seems to hold it back some. Cam is a custom grind (solid lifter) with only 20 degrees overlap, with BIG numbers on lift/dur.... so I can snap the throttle(s) and I've zero dead spots, or hesitation... she just pulls. I'm planning to pull this setup this summer and install my Eddy Airgap and Holley 750 HP Street....just for a change. I may have to opt'd for an bigger carb, but we'll see... Anyway.... Just sharing a little stuff with follow motor heads. Good luck.
 

Attachments

  • Engine.jpg
    100.2 KB · Views: 553
  • 4.jpg
    101 KB · Views: 416
  • DSCN1345.jpg
    71.2 KB · Views: 438
  • Duster 72.jpg
    96.6 KB · Views: 438
Hi Old Country, you sure those are Vette carbs?? they look identical to my setup which is the old mechanical DC setup originally designed for Ford NASCAR back in the day. The vette carbs were vacuum and also used on Norms cars, not saying they cant be vette carbs there was a company way back that modified 6 packs by putting sqirters and metering blocks on the outboards. From what i have read ditching the 6bbl for a good single or air gap on a motor like yours is around a 40hp gain... but that 6 pack looks cool!!!
 
heres a guy running a mod man
[ame="https://www.youtube.com/watch?v=vgPaiFT0550"]Indy Mod Man Intake 3x2BBL 452 Cubic Small Block Stroker - YouTube[/ame]
 
Old Country, I have brand spanking new 440 outboard carbs. My plan is very much like what you have now. I did want to try the 4.25 crank. At a .030/.040, overbored 360, it would displace 433/435 cubic inches.

I have Edelbrock heads, stock OOTB on my 360 now. My ('73) Cuda is a manual 4spd car with 4.10's. A cam is not yet choose for this build. But it will be a solid roller with as much lift as the heads can handle before stalling.

The goal is a mean street machine, very mean.
 
At this point, I think I can use the 430 outboard carbs well enough on a ported intake on top of a 430+ cube small block.

What about the center carbs differences?
 
The thing with the intake is all you can really do is a gasket match, but you can see from my pic how bad the core shift can be.
 
I think the really only difference in the center carbs besides jetting is the 440 has a idle cam thing(cant think of the name) on the drivers side but it bolts to the intake which you won't have the holes.So either will work,they are both 350 cfm.
The stock 440 carbs should work on your engine.
My 340 is .40 over with a cam too big for a stock converter(I think) with slightly ported 1.88 stock heads and the factory 6-pack setup works good with a lot of flexibility to go bigger.

EDIT:the idle cam thing can be removed and just use the idle screw.
 
410, perhaps you mean the idle seloniod? An electrical thing on the side of the intake just under the center carb?

EL5, I certainly plan to have the intake fully ported. Some runners slightly dip downwards. I do not know how well it will port out and flow, but is has to be a nice advantage when done.

The Mod man intake above is an interesting idea. How would it fit to the '70 AAR hood?
 
You must log in or register to reply here.
-

Back
Top