Thermoquad worth it - or no?

I have a line on a TQ 2146 carb. I have a 318 with a rpm air gap and eddy 800 now. I now the square bore won't work with the TQ. I also have a 408 with a Super Victor intake and a Holley 750 dp. Is a TQ a good choice, or a better choice. I thought they were higher cfm, but my brother told me only the aftermarket performer series were high cfm. Whaddya think?

I have always hered thermos suck no matter what. I am getting ready to purchase a holley 670 street avenger

the super victor will need an adapter for the TQ,,,,and I would keep the holley 750 dp ...

try and find parts for the TQ...

and the number you are listing is just on top cover...look on the base of the carb for the number of the carb..

I can not find a listing for a 2146 TQ. Normally they start with a 9 or a 6.

I found this e-bay ad; http://www.ebay.com/itm/Carter-Ther...y-Ford-GM-carb-600-/290621003947#ht_500wt_949

I noted the question(s) below the ad, "ask the seller a question" and the other numbers on it were 6463, which equals;

6453 74 360 HP AT F (3751434) 4098 5143 2005 1-1/2

According to the Vannth guide.

This would be the small 800 CFM carb (As there so called) This one comes off a early 360 HP engine with a auto. trans. and a .098 primary jet, a .143 secondary jet, and the rod is a 3 step at; .065 .055 .040

IDK what the stock step up spring is in terms of vacuum inch's until it pulls up, but you can use a AFB/AVS spring if your careful. There MUCH thinner.

While there CFM is great, the high flow ability is the secondary side. The small primary up front is about 200 cfm. The TQ can be made to work well. There not a high rpm carb. The Holley does better at a high rpm or velocity though it. Or at least that is what I have found. I guess, IMO that is.

The TQ is a pain to learn and get just right. You just might loose some hair over it. However, once you figure out the carb, they can be real gems. Not to mention, I have picked up gaggles of these carb for $20-$40 bucks. Cleaned and rebuilt them and have them run just fine. So for a rebuild kit and carb, 800 cfm at under $100... what is to argue about.

One of the short comings of the TQ is that it is a stock carb. Remember that. STOCK! How far can stock go in stock configuration? Well, it shows it's limits with big cams. The other problem is adjust-ability. You can have them worked on. Milled, modified, altered, bored out, add adjustable air bleeds, etc.... But now this is work to update a old stock carb.

Other guys will scream put a Holley on it, and, I can not argue with that. A stock Holley suffers from a very similar fate as the TQ. But parts are out there to fix that. Then a aftermarket Holley (Still a Holley brand/labeled) carb is even better yet.

TQ's work best as a dual purpose carb. Not to heavily cammed unless modified.
Keep the heat away from them TQ's.

In the end, you gotta run what your OK with, what ever you like.
Most people run a TQ because they want to run a TQ.
There's nothing wrong with a TQ.

The HIGH CFM TQ carbs were rated at over 1,000 cfm and are not good choices for the street at all. Unless you have a real monster in terms of power and cubic inch size.

And that is what I think.

By the way, does the Super Victor have enuff meat around the carb flange to cut away for a TQ? Just wondering. The MP M1 single plane intake would be intake of choice for this carb (Holley street Dominator is great as well or the seldom seen Offenhauser single plane spreadbore intake.) or a dual plane intake would be the Weiand Action Plus or Stealth modified. The Edelbrock LD-340 can be modded to work as well.

I read that the 2000 series were race carbs that ma Mopar gave their racers before it was released on any production car

The only problem I have ever run into with a Thermoquad is on a really radically cammed engine. It did not have enough vacuum to hold the metering rods down at idle. I really didn't mess around with it too much.....I probably couldda got it tuned right but I had an 800 DP that I just swapped out for it.

The only problem with tq's is most people dont know how to tune them.And parts can be hard to find. I have a collection of them,as thats the best way to find spare parts!

needsaresto said:

The only problem with tq's is most people dont know how to tune them.And parts can be hard to find. I have a collection of them,as thats the best way to find spare parts!

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That's true pretty much.....but parts can be found if you look hard enough.

Bobby, get rid of the step up spring on radical cams and just allow the internal egg cam to lift the rods.

rumblefish360 said:

Bobby, get rid of the step up spring on radical cams and just allow the internal egg cam to lift the rods.

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That was my thought, but I have never tried it. I take it that you have. Does it work ok? I know somebody had to figure out how to do it on big cam engines because they were used on SS cars quite successfully. Thanks. I may have to do that on my slant because it will have a pretty nasty little cam.

Not hi jacking, but now dealing with an addy(carter), almost same as afb; learning curve just to get correct jets and rods, without getting raped. And then get idle circuit leaner...

Bobby, the actual problem comes from timing of the rods coming up. The "Egg" or "Lobe" of the cam within the carb in the base plate can not exactly be changed out for a more aggressive ramp speed. Though it is pretty good as is, a bigger cam and the resulting change parameters are hard to predict (For me at least) On just how the engine wants the fuel curve to run. Since we know each engine is different, the complexity and combination probabilities are near endless.

the center screw for adjusting the rod height for lowering the rods into the jets or raising them changes the timing of fuel enrichment a little. Since the rod is deeper in the jet or not so deep in the jet. The time it takes to raise them is likewise shortened or lengthened.

Unlike a Holley, this cam is fixed, there are no replacement or swap cams. So, it kind of happens the same time every time. Only the delay of lowering or raising the rods for a quicker enrichment is possible.

Demonsizzler can ad adjustable air bleeds.this I have not looked into myself and do not know how he does it. I guess some thinking about it and time with a few carbs, I could figure it out. Not likely going to happen with me though. Not enuff time on my hands to do it. Also need a few things to experiment.

Adjusting the fuel curve on a TQ is a lot harder vs a Holley.

And this is a spot where most people throw in the towel on a TQ. I also do not blame them either.

Main jets that sit in the well (Primaries) are hard to come by. I bend AFB rods 3/4 inch's smaller to work as TQ rods. IF I am actually lucky enuff to get a TQ apart and I really mean apart, I can use a tap and re-do the main jet spot for use with Holley Jets.

Getting the cap under the jet off and still be able to re-use it is the golden trick. If it doesn't fall off to begin with, it's almost a 100% guarantee it will break and then your screwed, left with a door stop instead of a carb.

If they both fall off first, I'll tap the plastic body jet insert.

Pay close attention to jet heights.

Green, your cost of learning a AFB is time and spark plugs. Have at it. A helpful tool is a 02 sensor.Edelbrock has an inexpensive unit for around $100 I think. Comes with a bung to weld into the collector. (Not the reducer of the header)

Use that to help accelerate the learning curve. Works like a charm. A MOST helpful tool.

StrokerScamp said:

That's true pretty much.....but parts can be found if you look hard enough.

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I was referring to jets,specifically. One of those jet assortment kits shows up every now and then.Being such a rare thing though,it costs a pretty penny. It's the same with new tq bodies. When Tomco made em ,they were reasonable. Not anymore!! A new tq phenolic body will cost $200 or more nowadays.

I never use another carb over a Holley. Also, don't the TQ center sections tend to melt?

Mopar to ya said:

I have a line on a TQ 2146 carb. I have a 318 with a rpm air gap and eddy 800 now. I now the square bore won't work with the TQ. I also have a 408 with a Super Victor intake and a Holley 750 dp. Is a TQ a good choice, or a better choice. I thought they were higher cfm, but my brother told me only the aftermarket performer series were high cfm. Whaddya think?

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TQ's are great carbs in good shape. The High Performance carbs, 340, 360 HP, 400 HP, 440 HP, are set up better than the run of the mill carbs. Good gas milage and pulls like a freight train on the top. They were supposed to be faster behind an automatic trans since you could adjust the air valve to open without any bog. They can even get good mileage out on the highway. They are probably the best dual purpose carb there is. Hey, I even like Quadrajets for the same reason. Most people don't like either. Used to be able to get them cheap. All TQ's flow at least 750 cfm with those big secondaries. I do not have highly modified engines so I never had to tune too far from factory High Performance. The Carb number is on the drivers side rear mounting ear on a TQ. 2146 is not the carb number. TQ center sections do not melt. They keep the fuel cooler.

Tom Oliver said:

I never use another carb over a Holley. Also, don't the TQ center sections tend to melt?

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No, they do not melt. The "Phenolic resin" (SP?!) AKA plastic is almost the same compound as the new resin there using for the GM/Ford etc intakes the last few years.

What the big issue is with the TQ carbs and the rap they get for the center section of the carb is the heat of the engine can warp the middle plastic section. When the TQ was in full force, the engines started to run hotter and leaner due to the Gov.'s tighter tail pipe control.

The center section, if heated up to much, will warp. It is possible, however unlikely, that you can mill the top section flat. A lot of care must be taken to do this. By hand is the preferred method. Face down on sand paper. Mild warps can be cured this way. But the odds are low. The resin body can get really bad.

(Disassemble them cold at all times)

TQ's can also crack. Then they leak fuel all over the place. IF the crack isn't to bad, JB Weld can seal it up.
Sometimes, the crack is in the base of the carb and it may not be possible to fix. It depends on how bad the crack is.

The worst is when the bottom of the plastic bowl's little "Caps" that form a well for the primary jets break. You basically screwed then.

Long life from these carbs depends on them not over heating, keep them cool, run a thick base gasket like they did when new. Watch your engine temp's.

Rumble is right. I've never seen a badly warped body here in Canada,but usually the body is slightly warped enough to affect seal. I just lay a f;at piece of glass down on my bench top,tape some sandpaper down and then gently rub the body back and forth until it's flat.

Easy,and waaaaaaaay cheaper than a new one.

I've even had some success sealing those well caps rumble mentioned with j.b weld. I figure a better method would be to drill and tap the well bottom and install a pipe plug with jb as the thread sealer. Never tried it,but I think I will next time I find a leaky body.

I test the bodies with diesel,not gas. The diesel microscopically can get through smaller holes than water,so it's a sure bet if you have a leak,diesel will get through.

Well, I passed on the trade and sold my part outright. I can still get this carb. I thought I would offer him $50. It can't hurt to have a carb laying around. Think that is too much? Or too little?

The diesel microscopically can get through smaller holes than water,so it's a sure bet if you have a leak,diesel will get through.

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Really!? LOL, no chit! I didn't know that. LOL, leaned something today. Dang!

Mopar ta ya, $50 isn't to bad if it is basically un-rusted, a minor amount is OK, it happens, the crud level is low, not a greasy messy thing, operates freely, twist open the throttle plates and see. No gas sitting in it for months on end would be a big plus.

If it looks really good and you know or trust the seller with him saying it is a good carb, then no more than $100. I don't care what e-bay sell's them for. It's gotta be a real NOS part or seriously sweet for me to even think about going over a benji. ($100) I have shelf full of $20 TQ's.

hi, it's too bad you guys hate or dislike T.Q. carbs, in stock eliminator and super stock, we have to run the stock carb.those engines run very fast!!! it's like anything else, you learn how to make it work!! the holley is not the answer. the same thing is said about the quadrajet carb also. I have found in all the years of racing is, it takes a smart feller to use a T.Q. and a quad carb. as for the float bowl melting, that was caused by the exh being injected into intake maniflod under the carb. called EGR. just food for thought.

rumblefish360 said:

Really!? LOL, no chit! I didn't know that. LOL, leaned something today. Dang!

Mopar ta ya, $50 isn't to bad if it is basically un-rusted, a minor amount is OK, it happens, the crud level is low, not a greasy messy thing, operates freely, twist open the throttle plates and see. No gas sitting in it for months on end would be a big plus.

If it looks really good and you know or trust the seller with him saying it is a good carb, then no more than $100. I don't care what e-bay sell's them for. It's gotta be a real NOS part or seriously sweet for me to even think about going over a benji. ($100) I have shelf full of $20 TQ's.

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I give $20 max for a tq off a non running engine,sometimes only $10 if it's corroded.. Never actually paid more,as guy's always want silly $$ for a tq in good shape,performance series or not. I might pay $50 if it came off a running motor and was useable. Your gonna sink at least $50 into a tq to rebuild it,new floats,gaskets etc.

needsaresto said:

I give $20 max for a tq off a non running engine,sometimes only $10 if it's corroded.. Never actually paid more,as guy's always want silly $$ for a tq in good shape,performance series or not. I might pay $50 if it came off a running motor and was useable. Your gonna sink at least $50 into a tq to rebuild it,new floats,gaskets etc.

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X'2 though I guess I was thinking/replying from a view that it is/was recently a running TQ. Junkyard/swap meet TQ's are like you said.

Kit's are enuff money by themselves. IF a known rebuilder of these things takes there time, does a really nice job and makes it look brand new, I'll pay him his work fee. In this area, I don't mind so much.

That means no to 99% of you guys, I don't want your "Re-built" glass beeded TQ carb.