Author Topic: Which carb do I rebuild?  (Read 2773 times)

Offline hooD

  • detroit iron
  • Resident
  • *****
  • Posts: 2820
  • Motor City Made Muscle
Which carb do I rebuild?
« on: September 11, 2009 - 01:59:47 AM »
1st picture:  1973 original TQ with 12,600 miles used for 16 months then put into a box and stored until now.

2nd picture:
  1974 TQ bought brand new for $70 has been used for 35 years with 23,000 miles.  Carb is currently on car.  She's leaking gas.

Which one do I rebuild?  I'm leaning towards the original carb. 

Why did I replace the original carb you may ask?  Because it never ran right.  It would spit up through the back barrels when you nailed it.  The dealership could never figure it out.  They adjusted the air door many times with no luck.  I got fed up and replaced it with a Holley 3310.  That carb sucked big time, so I bought a new TQ in 1974 for $70 at the auto parts store (2nd picture).

The 1974 carb has been perfect up until a few years ago when she started leaking gas from the bottom throttle shaft area and would drip gas onto the intake manifold.

So, if you were me, which one do I rebuild? 
I'm not looking forward to this mission, but it has to be done.  I already have the rebuild kit. 
-Larry
member since AUG 2007
http://www.youtube.com/watch?v=NvrWiLgDm7Y

southeastern michigan usa
             
 
            
1973 'CUDA 340
 
original owner
37,117 miles
  
:grinyes: *click my E-Body* :grinyes:




Offline Bullitt-

  • Permanent Resident
  • *******
  • Posts: 12167
  • Better Things To Come Member Since 2/16/06
Re: Which carb do I rebuild?
« Reply #1 on: September 11, 2009 - 07:02:18 AM »
I'd be tempted to build the original 1st... I assume your car still runs with the one on there now..
 There are only a couple of reasons gas would leak out the shaft, one the floats are not closing the needle valves or the needle valves are bad, the other the bottom jet sumps are leaking. 
 I see on you OE carb. the secondary air valve is hanging open, so the spring needs adjusting or something has it in a bind.
Wade  73 Rallye 340..'77 Millennium Falcon...13 R/T Classic   Huntsville, AL
Screwed by Photobucket!

Offline mrob

  • Jr. Member
  • **
  • Posts: 200
Re: Which carb do I rebuild?
« Reply #2 on: September 11, 2009 - 10:02:24 AM »
hood - not trying to hijack the thread, but was your engine painted orange from the factory? AFAIK, 340's were painted blue in 73. Just curious. I have a 73 Cuda too and my motor is blue.

Offline burdar

  • Sr. Resident
  • ******
  • Posts: 5925
Re: Which carb do I rebuild?
« Reply #3 on: September 11, 2009 - 10:40:07 AM »
Since you already have the rebuild kit...I would rebuild the 74 that you bought at the parts store.  Then I would send your origonal out to Scott Smith and have him do a complete OE rebuild and plate job on it.

I'm sending my origonal Carter 2-barrel to him.  I'll get it back looking brand new.

Offline hooD

  • detroit iron
  • Resident
  • *****
  • Posts: 2820
  • Motor City Made Muscle
Re: Which carb do I rebuild?
« Reply #4 on: September 12, 2009 - 01:02:45 AM »
hood - not trying to hijack the thread, but was your engine painted orange from the factory? AFAIK, 340's were painted blue in 73. Just curious. I have a 73 Cuda too and my motor is blue.

Yes, I repainted the engine "hemi orange" for lack of having one back in 1974.  I seriously wish I hadn't done that.  I want to go back to chrysler blue as it was from the factory.  I just haven't taken the time to do it.  I have the original air cleaner which is in mint condition.  Picture below is from mid 1973.

2nd picture is how it currently looks.
« Last Edit: September 17, 2009 - 01:23:52 AM by hooD »
-Larry
member since AUG 2007
http://www.youtube.com/watch?v=NvrWiLgDm7Y

southeastern michigan usa
             
 
            
1973 'CUDA 340
 
original owner
37,117 miles
  
:grinyes: *click my E-Body* :grinyes:

Offline hooD

  • detroit iron
  • Resident
  • *****
  • Posts: 2820
  • Motor City Made Muscle
Re: Which carb do I rebuild?
« Reply #5 on: September 12, 2009 - 01:06:37 AM »
Since you already have the rebuild kit...I would rebuild the 74 that you bought at the parts store.  Then I would send your origonal out to Scott Smith and have him do a complete OE rebuild and plate job on it.

I'm sending my origonal Carter 2-barrel to him.  I'll get it back looking brand new.

Send me Scott Smith's email or website so I can check him out, if you have that information please.
-Larry
member since AUG 2007
http://www.youtube.com/watch?v=NvrWiLgDm7Y

southeastern michigan usa
             
 
            
1973 'CUDA 340
 
original owner
37,117 miles
  
:grinyes: *click my E-Body* :grinyes:

Offline hooD

  • detroit iron
  • Resident
  • *****
  • Posts: 2820
  • Motor City Made Muscle
Re: Which carb do I rebuild?
« Reply #6 on: September 12, 2009 - 01:17:37 AM »
I'd be tempted to build the original 1st... I assume your car still runs with the one on there now..
 There are only a couple of reasons gas would leak out the shaft, one the floats are not closing the needle valves or the needle valves are bad, the other the bottom jet sumps are leaking. 
 I see on you OE carb. the secondary air valve is hanging open, so the spring needs adjusting or something has it in a bind.

I'm leaning towards rebuilding the original also.  It has very, very limited actual usage on it.  But after sitting for 35 years, I think it would need new gaskets, O rings and whatever else my rebuild kit has to offer.  Plus a few minor adjustments.

The current carb works, but it leaks from the bottom shaft area on both sides.  This makes restarting the engine a PITA, because its flooded.  Maybe if I can successfully rebuild one carb, the goal would be to do the 2nd carb.

-Larry
member since AUG 2007
http://www.youtube.com/watch?v=NvrWiLgDm7Y

southeastern michigan usa
             
 
            
1973 'CUDA 340
 
original owner
37,117 miles
  
:grinyes: *click my E-Body* :grinyes:

Offline Topcat

  • C-C.com Expert
  • ********
  • Posts: 15376
  • Member since 9/16/04
Re: Which carb do I rebuild?
« Reply #7 on: September 12, 2009 - 01:32:41 AM »
Since you already have the rebuild kit...I would rebuild the 74 that you bought at the parts store.  Then I would send your origonal out to Scott Smith and have him do a complete OE rebuild and plate job on it.

I'm sending my origonal Carter 2-barrel to him.  I'll get it back looking brand new.

 :iagree:

Scott knows these TQ's well. You won't be dissapointed if you do send it to him.
Mike, Fremont, CA.


Offline hooD

  • detroit iron
  • Resident
  • *****
  • Posts: 2820
  • Motor City Made Muscle
Re: Which carb do I rebuild?
« Reply #8 on: September 12, 2009 - 02:04:08 AM »
:iagree:

Scott knows these TQ's well. You won't be dissapointed if you do send it to him.

Can you hook me up with Scott's contact information?
-Larry
member since AUG 2007
http://www.youtube.com/watch?v=NvrWiLgDm7Y

southeastern michigan usa
             
 
            
1973 'CUDA 340
 
original owner
37,117 miles
  
:grinyes: *click my E-Body* :grinyes:

Offline Topcat

  • C-C.com Expert
  • ********
  • Posts: 15376
  • Member since 9/16/04
Re: Which carb do I rebuild?
« Reply #9 on: September 12, 2009 - 02:06:37 AM »
PM sent
Mike, Fremont, CA.


Offline burdar

  • Sr. Resident
  • ******
  • Posts: 5925
Re: Which carb do I rebuild?
« Reply #10 on: September 12, 2009 - 09:08:19 AM »
For everyone else that may need a carb done...here is Scott's website.

http://www.harmsauto.com/

Offline Super Blue 72

  • Permanent Resident
  • *******
  • Posts: 12711
  • "Big 'n Little" Member since 8/9/05
    • Phil's Super Blue '72
Re: Which carb do I rebuild?
« Reply #11 on: September 12, 2009 - 11:57:26 AM »
Hey Hood, I was wondering if you had replaced the gas tank or other item in the fuel system in the pastfew years when the gas started leaking from the throttle shaft areas?  :clueless:  REason why I ask is that my TQ had the same problem and someone (Sorry, forgot who...) suggested it might be when I changed out my gas tank some debris got caught in the needle/seat area, which is why I thought I had the dripping.  It dripped only when the engine was shut off.  But now it isn't doing it so maybe whatever it was dislodged it'sself.   I dunno....  :dunno:

The original (1st carb) looks tempting to rebuild but I guess the known problem with the secondaries makes me wonder.  I'm not that familiar with the TQ circuit but if you follow the circuit for the secondaries and find the theory behind how it works you might be able to fix/adjust it.  :dunno:
1972 Dodge Challenger Rallye 340, AT, Code TB3=Super Blue, SBD=8/17/1971.  Yes, a Rallye without the fender louvers from the factory because of the body side molding option.

Pic #2 and 3 of my ARII 1/24 scale model car 

Phil in New England-Massachusetts  Always thank God for what you have!

http://www.cardomain.com/ride/456046/1972-dodge-challenger

Offline hooD

  • detroit iron
  • Resident
  • *****
  • Posts: 2820
  • Motor City Made Muscle
Re: Which carb do I rebuild?
« Reply #12 on: September 15, 2009 - 01:18:52 AM »
Hey Hood, I was wondering if you had replaced the gas tank or other item in the fuel system in the pastfew years when the gas started leaking from the throttle shaft areas?  :clueless:  REason why I ask is that my TQ had the same problem and someone (Sorry, forgot who...) suggested it might be when I changed out my gas tank some debris got caught in the needle/seat area, which is why I thought I had the dripping.  It dripped only when the engine was shut off.  But now it isn't doing it so maybe whatever it was dislodged it'sself.   I dunno....  :dunno:

The original (1st carb) looks tempting to rebuild but I guess the known problem with the secondaries makes me wonder.  I'm not that familiar with the TQ circuit but if you follow the circuit for the secondaries and find the theory behind how it works you might be able to fix/adjust it.  :dunno:

Yes, I did replace the fuel tank several years ago when the original developed numerous leaks.  I got a tank from a '70 cuda at the junk yard that has been problem free for years.  I would have to look in my log book to check the year I did that.  But you make an excellent point.  I really don't think my throttle shaft bushings are worn to cause the leak I have.  Maybe there is some debris in the carb that is causing the leakage.  Thanks for the input!
-Larry
member since AUG 2007
http://www.youtube.com/watch?v=NvrWiLgDm7Y

southeastern michigan usa
             
 
            
1973 'CUDA 340
 
original owner
37,117 miles
  
:grinyes: *click my E-Body* :grinyes:

Offline Super Blue 72

  • Permanent Resident
  • *******
  • Posts: 12711
  • "Big 'n Little" Member since 8/9/05
    • Phil's Super Blue '72
Re: Which carb do I rebuild?
« Reply #13 on: September 15, 2009 - 08:39:46 AM »
Hood, just wondering, did the leak at the throttle shafts happen with the engine running or when the engine was off?  Mine leaked when the engine was off.  I could see a good, constant drip when the engine was off.

The throttle shaft area isn't a perfect seal.  Vacuum should draw the fuel past the throttle shaft with the engine running.  :2cents:
1972 Dodge Challenger Rallye 340, AT, Code TB3=Super Blue, SBD=8/17/1971.  Yes, a Rallye without the fender louvers from the factory because of the body side molding option.

Pic #2 and 3 of my ARII 1/24 scale model car 

Phil in New England-Massachusetts  Always thank God for what you have!

http://www.cardomain.com/ride/456046/1972-dodge-challenger

Offline hooD

  • detroit iron
  • Resident
  • *****
  • Posts: 2820
  • Motor City Made Muscle
Re: Which carb do I rebuild?
« Reply #14 on: September 16, 2009 - 01:40:36 AM »
Hood, just wondering, did the leak at the throttle shafts happen with the engine running or when the engine was off?  Mine leaked when the engine was off.  I could see a good, constant drip when the engine was off.

The throttle shaft area isn't a perfect seal.  Vacuum should draw the fuel past the throttle shaft with the engine running.  :2cents:

Phil, Seems that the leak is after shut down.  I replaced the tank in 1982 for $15. 

I also looked at why the air valve door on my OEM TQ was limp.  There is NO spring in there to put tension on the secondary air door.  Those morons at the dealership must have yanked it out and I find out about it 36 years later.  ERRRrrrr.  Do they still make the spring, I wonder?   :dunno:
-Larry
member since AUG 2007
http://www.youtube.com/watch?v=NvrWiLgDm7Y

southeastern michigan usa
             
 
            
1973 'CUDA 340
 
original owner
37,117 miles
  
:grinyes: *click my E-Body* :grinyes: