Carburator suggests PUUUULLLLEEEEZZZEEE

[billschroeder5842]

I took a PERFECTLY running 1975 roadrunner and turned it into "Crazy Eyes" from "Orange is the new Black"

I had a totally stock Thermoquad that was really running (damn near perfect) really well, but was progressively leaking more and more gas. It really became a safety issue.

I bought a rebuilt Thermoquad and got the car to idle really smooth, however when is get to about 1700 rpms, it begins to buck, surge and backfire. WTF?

I spoke with my local trusted guy about tuning the carb. He told be to not waste my money on tuning the thermoquad but suggested getting another replacement carb that is more bullet proof.

So, I'm looking for a damn near stock replacement--dependability is more important than boy racer performance at my age.

I'd really like to keep all the stock stuff in place--moving the coil for dual fuel line, or crazy carb spacers or worrying about the dual snorkel air cleaner fitting have no appeal. Plug and play is where I'm headed-this thing is a cruiser.

BTW... I have a totally stock 400, 4bbl with 8:2 compression, stock intake, stock duals, stock dizzy and bare bones Canadian emissions.

Any recommendations on a "straight out of the box bullet proof carb?"

[Dino]

A Street Demon 1901 would be my first choice.  It's basically a modern spread bore carb like the T Q and you can even get them with a composite bowl.

http://www.jegs.com/i/Demon+Carburetion/333/1901/10002/-1?CAWELAID=1710560289&CAGPSPN=pla&catargetid=230006180000848874&cadevice=t&gclid=CO-tkYaMt8MCFQeBaQodKKoA_A

[Cooter]

Out of the box Holley 600 vac. Secondary and electric choke. I didn't wanna kick u in the balls about that TQ, but.......

[68CoronetRT]

IMO I just went from a 770 vac secondaries to a 600 double pumper(to try for now) and I will NEVER go back to a vacuum secondary carb. I have a 780 double pumper being tuned up for me right now. Again, just my opinion .

[Dmichels]

There is no reason the stock carb should work for your stock set up. Yes you can get some decent aftermarket cars that people have suggested to run well. Where is the leaky old carb that ran well? Rebuild that and put it back on
Dave

[myk]

I'm usually the first one to throw out "old" parts in favor of newer and shinier ones, but in this case I have to agree with the poster above me.  If you had a 'carb that allowed the car to run "damn near perfect," I would do whatever I had could to make sure that 'carb stays with the car...

[1973rallye]

When we chatted before Bill I had mentioned my TQ woes. I went with the Street Demon carb for my 340. It bolts right on with minimal alterations. We did have to make a bracket to extend the OE throttle stud as the Street Demon carb was narrower than the TQ. If you choose to go this route be sure to read the online installation manual beforehand. They recommend a replacement throttle stud but it's not mentioned on their site. I called them with that criticism and they sent me one free. Didn't end up using it because of the bracket we made. Long winded story. Very happy with the carb. Best of luck. Ray

[69wannabe]

I agree with Dino on this one, that demon carb looks like a TQ replacement but alot better!!! I have not heard of anybody purchasing one of these yet but the price looks good! Would be interested in hearing some reviews on this carb.

[A383Wing]

I say find what the leak was on the original carb, fix that, and put it back on

[Bronzedodge]

Folks that run Thermoquads generally like them a lot if they can get tuned in, adjusted correctly, etc.  A book and specs helps a lot.  The big problem is the plastic resin main body, they get old, dry and sometimes warp.  There was an outfit known as Tomco that had the replacement main bodies, but they seem to have been bought by Champion Co (not related to spark plugs) and their website is broken.

There is this excellent guide by Gary Lewallen:  http://carbkitsource.com/carbs/tech/Carter/pages/tqguide-Vaanth.html

Unless you really want the originality, the Demon or other replacement is the way to go.

[ODZKing]

They are definitely a love or hate it type of carb!  I have a TQ on my 73. I wanted to put it back to original so I found one, had it rebuilt and installed it.  The wrench that does some work on my 67 and 73 hates them. Told me NOT to do it. And I haven't been able to find anyone who is expert at these so I have put together a bunch of information I found on the web and sort of messed with it myself. I haven't got it right yet, but I am going to keep trying this season before I give up.  But I can see why folks hate them for sure.  My AFB compared to this TQ is pretty much plug and play!
Here is the page with 3 guides that may help including some of Gary's info incorporated.
http://www.retrorarities.com/ChargerInfo.htm

[billschroeder5842]

Thanks everyone! I appreciate your thoughts!

So, the old carb is gone.... a causality of the core exchange wars

I did order a Demon 1901. It arrives tomorrow so it will go on tomorrow night.,

I read a lot of reviews, both on this site and on other. The Demon has met with universal approval so I'm excited.

I also chose the Demon because (it appears) to be pretty straight forward installation. The Holley had the dual fuel line that would require moving the coil and remounting it. Blah. Been there, done that.

Some of my stock emissions junk will get disconnected and capped. It will be a small proce to pay if the carb works as advertised.

I'll post my experiences and let you all know how it goes!

[Sublime/Sixpack]

 Interesting thread. Maybe I've been lucky but I have two old Thermoquads that have been in service for several years and they still work fine. I do understand that the phenolic center part can warp and cause problems but the thermoquad is my favorite production 4 barrel carb.
Not sure I understand the big mystery some so called mechanics seen to have with them, unless it's just a mindset or ignorance on their part. And I do believe that buying any rebuilt carb can be a real crap shoot. 

I have considered the Demon 1901 for a new engine I have that has a spread bore intake on it and needs a carb. Looking forward to more positive input on the 1901.

Hope it works out for you bill5842.

[billschroeder5842]

WOW
WOW
WOW

I just finished and what a difference. Really noticeable. I would describe the engine as now having a feeling of "smooth power."

Now, I only drove it about 4 miles on a quick test, but I ran it through the paces; start, stops, punch it. No flat spots, bogs, or hesitation. Totally different car.

Observations....

1. Super straight forward installation, especially swapping with Thermoquad.
2. Order the Mopar throttle linkage. I had to kludge one together so I can drive this weekend but will order the "official" one Monday.
3. You will need the spacer or use the 1/4 inch gasket from the Thermoquad. If you don't you will not be able to open the butterfly's all the way as it hits the intake.
4. The rich/lean was spot-on out of the box. My vacuum gauge showed 19 and while I messed with the screws, I really just needed to leave it alone.
5. The electric chock worked as advertised.
6. I just had to turn the idle speed down. Out of the box it was 1000 so I knocked it down to 750.
7. Started really pretty quick and settled down almost immediately.

The purist in me want to keep the emissions stuff, but reality is that the carb does not have all the ports for the lines. So tomorrow I'll undue what I can, fool around with the timing and a few other setting.

I'm SUPER happy 

So does anyone want a 1 hour old, rebuilt Thermoquad? Cheap?

[Mopar Nut]

Post a picture of your new carb when you can and/or a Youtube of your car running.

[billschroeder5842]

*** TEST DRIVE ***

So this morning I went on a 20 mile or so drive. Here is what I found.

Cold Start-- stomp on the gas and then a tap (tap) on the ignition and immediately springs to life. It never started so quick. Initial cold idle at 1000 then crept to 1400. All good in my book.

Driving- I taped the gas and the cold idle backed off to the 750. Super smooth. I took it on some back roads and then on to a interstate (Texas 114 for those in the metroplex). Quicker off the line and climbed quickly to 85. No surges, hesitation-- just smooth.

Needed adjustments- My transmission is shifting a little later than before. Nothing out of control, but it "holds on" a bit longer. 

[Sublime/Sixpack]

 

[Dino]

Sweet!  I may end up with one of those myself.