News:

It appears that the upgrade forces a login and many, many of you have forgotten your passwords and didn't set up any reminders. Contact me directly through helpmelogin@dodgecharger.com and I'll help sort it out.

Main Menu

Carburetor - Intake Combination - 400 Magnum

Started by WindJammer, April 14, 2015, 11:11:41 PM

Previous topic - Next topic

WindJammer

Hey guys, I have a 1972 Charger my Dad bought new in 72'

He had the factory carb replaced way back. A Holley is all I can determine. The mech who did it said that it would get him where he needed to but would need to be replaced.

Well I want to replace it now but im not sure what with. Ive read here and there a Holley 750 double pumper should do just fine. Ive read some articles too about CFM up to 850 but that particular engine was on a dyno and an intake manifold the size of a toilet! Im not a mechanic but I know there are a lot of solid guys here that have helped many out with some great ideas.

I know there are countless things to consider. Right now the engine is straight factory original. At some point I would like to heat it up a little bit with a better intake manifold, higher performing cam, valve job etc.

But heres my question: Is there a carb out there that can get me driving it around this summer as a bolt on AND give me room to improve and expand with the rest of the block when the time comes??

I have a bitchin' mechanic that wants to do an engine flush and compression test etc to see where see are at for a starting point. Any tips would be great!

Oh and some pics!! Original Paint and vinyl hard top

c00nhunterjoe

4777 holley (650) or 4779 (750) if you plan to do a cam intKe and headers.

BSB67

Do you know specifically what is on it now?  That should be a spread bore intake manifold, right?

I there something actually wrong with what you have now?

500" NA, Eddy head, pump gas, exhaust manifold with 2 1/2 exhaust with tailpipes
4150 lbs with driver, 3.23 gear, stock converter
11.68 @ 120.2 mph

WindJammer

The intake manifold is factory. And it does have a little space between it and the block.

I need to get a better look at the Carb and get some digits back to you. All I have is the conversation the mech had with my Dad years ago. My Dad says it never had the same power since it was swapped. Ill throw in a few more pics too.

myk

Do you know the 'carb is "bad?"  Resist the temptation to buy a shiny new 'carb and make sure that the 'carb you have now is properly set up and in good condition.  The most powerful engine in the world would be a mess if the fuel delivery wasn't properly tuned...

WindJammer

Quote from: BSB67 on April 16, 2015, 07:45:01 PM
Do you know specifically what is on it now?  That should be a spread bore intake manifold, right?

I there something actually wrong with what you have now?

Heres what I found:      Not a Holley!  Its a Carter, Thermo-Quad 6-2080

I attached a pic. of the set up.

WindJammer


Ghoste

A well set up TQ is not a bad carb you know.

BSB67

You still have not answered the question: what is wrong with how it runs now?  It is always good to find out what is actually wrong before you go replacing parts.  Memories are not always reliable.  How long ago was it replaced or worked on by the mechanic?  Some folks that don't know too much about cars often times rely way too much on what a "mechanic" says or does.

Why was the carb replaced I the first place?  Did replacing it fix that problem? How do you know that it was really replaced?  How do you know that the mechanic did it correctly? or did not screw up something else?  

Your problem could be the carb, and you could just replace it, but what if the problem does not go away?  What will you replace next?

I would at least tell us what the problem is, check or replace all of the vacuum lines. put fresh plugs in it, check the plug wires, and check the timing.  If you are in the hobby for the long haul, after you check all the items mentioned, maybe rebuild the carb you have.


500" NA, Eddy head, pump gas, exhaust manifold with 2 1/2 exhaust with tailpipes
4150 lbs with driver, 3.23 gear, stock converter
11.68 @ 120.2 mph

WindJammer

Quote from: BSB67 on April 26, 2015, 06:35:22 AM
You still have not answered the question: what is wrong with how it runs now?  It is always good to find out what is actually wrong before you go replacing parts.  Memories are not always reliable.  How long ago was it replaced or worked on by the mechanic?  Some folks that don't know too much about cars often times rely way too much on what a "mechanic" says or does.

Why was the carb replaced I the first place?  Did replacing it fix that problem? How do you know that it was really replaced?  How do you know that the mechanic did it correctly? or did not screw up something else?  

Your problem could be the carb, and you could just replace it, but what if the problem does not go away?  What will you replace next?

I would at least tell us what the problem is, check or replace all of the vacuum lines. put fresh plugs in it, check the plug wires, and check the timing.  If you are in the hobby for the long haul, after you check all the items mentioned, maybe rebuild the carb you have.



I asked my Dad your questions and he said that the carb he had on before was pushing out too much fuel. So much so, he was afraid of it catching fire. The problem was solved once the carb was replaced OR re-tuned. BUT he said the car never had the same power. I drove the car around in High School 1989. It ran ok. It could be a pain to start on occasion. And would want to over heat which I always kept an eye on.

Heres a list of what I have done to date:
I dropped the fuel tank and cleaned it out, installed new fuel pump and fuel filter.
Replaced the plugs, Plug wires and distributer cap.
Installed a new radiator and thermostat.

Do you know if the Thermo-Quad 6- 2080 came standard on the 72' 400? If so I think its safe to assume that the mech just tuned it. Which would be fine to just rebuild and get it tuned properly. If however the 6 - 2080 came off some other type engine that limits the performance of what I have Id like to replace it.

Ghoste

6-2080 is the casting number for the upper half, the model number will be four digits followed by an "S" and it should be stamped on the flange the mounting bolts go through somewhere.  But I believe in either case the original carb would have been a Holley on there.  :shruggy:
To a degree though I think you might be swatting at flies in the dark here.  There could well be a problem with that Carter, but there might not be.  Like I said, a well set up TQ is a pretty good street setup.  There may be some other issue or combination of issues at work here or you may not have a problem at all just like bsb said.

BSB67

Pretty sure all 400 had TQs.  Any properly tuned TQ will be capable to support more power than any factory 400.

So, is it running now or not?  I'm still not clear what the problem is.  It ran okay in 1989, but you want to fix a claimed power loss issue from the 1980 with a new carb today?  Sorry, I just not following.

500" NA, Eddy head, pump gas, exhaust manifold with 2 1/2 exhaust with tailpipes
4150 lbs with driver, 3.23 gear, stock converter
11.68 @ 120.2 mph

WindJammer

Quote from: BSB67 on April 29, 2015, 09:54:51 PM
Pretty sure all 400 had TQs.  Any properly tuned TQ will be capable to support more power than any factory 400.

So, is it running now or not?  I'm still not clear what the problem is.  It ran okay in 1989, but you want to fix a claimed power loss issue from the 1980 with a new carb today?  Sorry, I just not following.

That was my thought too, looking online TQs were pretty much the standard. Back to your question=Yes it runs now. But I have trouble with the choke plate. Many times I need to manually manipulate the choke plate to get the engine started. It takes 2 fools to start the car. One at the ignition and me at the carb.  :eek2: The car ran OK in 1989 but I know it could have run better. Back to my question = is there a carb that will support my factory 400 engine and support any modest performance mods that I make in the future. Well, It sounds like I should get my TQ tuned/rebuilt drive it around for a while and not mess with another carb until after I make upgrades to my factory 400.

new2muscle

 Most TQ's will flow 750 CFM....... If its the right carb (bigger secondaries), it can flow 850 CFM. You certainly aren't gonna starve the engine. Having said that, the issues with tuning TQ's are many. But when you get them right, they work GREAT.

If it were my car, I'd stick with the TQ. Good mileage when you keep your foot out of it, but flows like crazy when you don't.

That's just my opinion.

TQ's are a love them or hate them carb. Depends on personal experience.

ODZKing

New2 is absolutely right. I fooled my my TQ for months and could never get it right. I was very close to converting it to an Edlebrock I was so frustrated.
Finally I broke down and took it to a fellow and within minutes he had it running properly. Vacuum adjust is key and ignore all the various 1 turn/2 turns etc. It needs to be set up with vaccum to run properly, at least mine did.
They are nothing like an AFB or AVS. My AFB on my 67 runs like a watch. But I have to say now that the TQ is running right, with a proper choke control it is nice.