Fuel System: Thermoquad Carb

[JoeHall]

Is anyone familiar with the Thermoquad ? (Not to be confused with Quadrajet.) I understand Thermoquads were Mopar's attempt to deal with vapor-lock in the 1970-80s. Have heard both the Quadrajet & Thermoquad are both cantankerous, but if not prone to vapor lock, they may be a good answer for driven Studes. Adapting the spread-bore to a Stude manifold is not an issue.

On fleabay, I see there is no shortage of NOS and rebuilt ones, and range from $100-250. One jetted for a 318 motor may be close enough for a Stude 289. I also see they have a divorced choke, which may call for some "Yankee enginuity". Very few are listed with electric choke.

Does anyone have any actual experience with them, either on Studes or Brand 'X' cars? Do they reduce vapor lock at all ? How about MPG ?

Thanks

[SN-60]

Carter Thermo-Quads were bad news when they were new....and I'm sure the situation hasn't improved! GM Quadra-Jets are much better. Stay away from the Carter Thermo-Quad!!

[Mike Van Veghten]

Here we go again...

I bought a new Thermoquad and put it on the 327 in my 59 El Camino.

I had no, zero, none, problems with it.

I like to experiment, I always have. The Thermoquad was somewhat of an experiment. New from Glendale Speed Equipment. As noted, no problems. I liked the adjustability of it, sorta like the Quadajets. At the time, this was my only vehicle and driven daily. As I recall, it was on the car for about two years, and it got sold with the car when it was sold.

As far as I see, the ONLY problem with the Thermoquad today...is finding one that has "all" of the threads intact in the plastic body, and of course the throttle shafts being loose as with any old carbureter.
The Edelbrock carb. on my Lark...it's shot from many miles from two different cars...the butterflys never shut right anymore. Sometimes it goes to idle by itself, sometimes I have to give the pedal a little hit, to "snap" the butterflys shut..!

If the threads are good and the throttle shafts are tight, go for it. But DO NOT buy one without having in hand to fully inspect first.

Mike

[Noxnabaker]

Thermoquads are real GOOD carbs!
I just had work on two Quadra-Jet's & one Thermoquad & I can't see what's so much better with a Quadra-Jet, I find the Thermo-Quad loads easier.
As for threads in the middle-section, I'm not sure there are any...

[SN-60]

Thermoquads are real GOOD carbs!
I just had work on two Quadra-Jet's & one Thermoquad & I can't see what's so much better with a Quadra-Jet, I find the Thermo-Quad loads easier.
As for threads in the middle-section, I'm not sure there are any...[ATTACH=CONFIG]20957[/ATTACH]

You'd have to have worked the Chrysler dealerships when Thermo-Quads were first introduced to understand. Carter Thermo-Quads=Junk!!

[bezhawk]

How about this one??????http://www.demoncarbs.com/1901.asp
Why use worn out 30 year old junk thats sized three times larger than you can use?

[SN-60]

How about this one??????http://www.demoncarbs.com/1901.asp
Why use worn out 30 year old junk thats sized three times larger than you can use?

This carb is basically an Edelbrock (Carter) "knock off' with some cute tweaks.

[bezhawk]

This carb is basically an Edelbrock (Carter) "knock off' with some cute tweaks.

Yes, by being totally different....that's really "cute"

[SN-60]

Yes, by being totally different....that's really "cute"

I guess carbs aren't Your game.....eh Bez?

[1962larksedan]

Thermoquad: Carter discontinued it in 1984 so it evidently was not that good forcing Chrysler to go with Quadrajets on the few remaining 4 barrel equipped V8 they had left.

[SN-60]

Thermoquad: Carter discontinued it in 1984 so it evidently was not that good forcing Chrysler to go with Quadrajets on the few remaining 4 barrel equipped V8 they had left.

Yes, it was something that was tried out with the best of intentions.......but turned out to be nothing but a headache. That happens sometimes.

[bezhawk]

I guess carbs aren't Your game.....eh Bez?

I guess not.
I guess you've never visited my blog?
I guess by having a phenolic body, adjustable secondary air valve, "goggle" shaped one piece secondary throttle valve makes them exactly like a Edelbrock/Carter?
Maybe you'r saying since it has metering rods it's the same? (just like the Rochester does too)....in fact, Rochester 4MV have secondary metering rods! (they must be 'doubly' a copy ???)

[SN-60]

I guess not.
I guess you've never visited my blog?
I guess by having a phenolic body, adjustable secondary air valve, "goggle" shaped one piece secondary throttle valve makes them exactly like a Edelbrock/Carter?
Maybe you'r saying since it has metering rods it's the same? (just like the Rochester does too)....in fact, Rochester 4MV have secondary metering rods! (they must be 'doubly' a copy ???)

The 'Street Demon' may be a very good carburetor....I really don't know.... but anyone that can see, and knows carbs, should be able to tell from whence it came! (In My opinion)

[Paul Keller]

The Street Demon received a very good response by "Engine Masters" magazine - That, IMHO, is a big plus.
Paul TK

[junior]

so i just did some snooping on google and came up with this....great primer on carter carbs. found it very interesting what was said about warping of the thermoquad body...something I remember about the reputation of the tq carb. regards, junior

http://www.thecarburetorshop.com/CarterFourBarrelCarburetors.htm