Thermoquad vs Edelbrock

-
7

72dart

Mopa
Joined
Nov 22, 2004
Messages
513
Reaction score
68
Location
PTC
I have a 71 demon 340, automatic trans with a 71 thermoquad that sometimes has an idle problem and stalls out. It also seems to to to bog down somewhat on acceleration from a dead stop. I am thinking of replacing it with an Eddy for simplicity and reliability reasons. I had a Carter on a 360 for 22 yrs with no problems ever on a street driven car which is what I will use the Demon for. I know some will say to keep what was original on a 340 car but I do not have the skills to tune a thermoquad and just want a good looking street car that is fun to drive and reliable. What are your thoughts and opinions on this as I make my decision.
 
I have an eddy on my 340 and love it. Tried a Holley just to see the difference and put the eddy back on. My carb is a 750 and it works perfect!!
 
You will need an adapter to run the Eddy. Why not send your Thermoquad to Harms Auto to get restored ? The 71 T-Quad is a rare piece so hold on to it.
 
I went with a #1406 600 edelbrock , on my 73 340 , had to change jets and , metering rods , and went with an orange spring in the kit to get rid of hesitation . A stock edelbrock is to lean for the 340 , it was on mine anyway , spacer plate , and you will need a #1481 edelbrock throttle cable adaptor.You can try one stock might be ok, but i tried three different eddy,s andwhen i changed the internal parts , works perfect.
 
I'd trade you a eddy 600 cfm manual choke verson ( #1405 I belive), and adapter plate, for your thermoquad. PM me if interested
 
Send it to a compedent rebuilder and get
another 40 years of reliable troublefree service from it.
You will not gain anything using the Eddy.
 
Might just need a rebuild. Could be Shot needle and seat leaking causing a flooding condition at idle and a shot accel pump for dead stop acceleration.

Either way, it's not too hard to take a carb off and put it on. As long as you keep the old one you aren't hurting the cars value.

Keep in mind the eddy might need a little tuning though to get it right.:thumblef:
 
Give Demonsizzler a shout, he is a whiz with TQ's. He rebuilt and tuned one for my old F250 4x4 with a 351. It ran like raped ape! I will definetly repeat with my 71. 340 TQ!
 
Will a rebuilt or tuned thermoquad need to be retuned on occasion or will it stay reliable?
 
all carbs need some kind of maintenance over the years..but at least with the eddy, parts can be found relative easy....

if it the original carb..put it in a plastic bag and box for future restoration...the 71 TQ cores are expensive these days..
 
I worked in chrysler dealerships for years back in the era, and thermoquads have a tendency to warp the plastic fuel bowls. Especially if the screws work loose. I'v replaced a lot of fuel bowls on these over the years. I remember it was a big problem with the lean-burn era cars, ( cordobas etc.) Many times you can sand them flat if there not warped bad, but that usally not the case. Most of the time the idiling problems come from two small round gaskets down in the fuel bowl that leak. I just rebuilt the one on my Lil red express, as they were leaking. Runs great now.
 
I just did the TQ on my hopped up 318. As was stated the o rings on the primary discharge tubes at the bottom of the float bowl needed replacing. TQ's are fairly easy to tune especially if it is stock for your motor. When they are right you can't beat them on a street car.
 
Picture of the carb.
 

Attachments

  • THERMOQUADEXPLODED.jpg
    215.8 KB · Views: 1,221
fanofpetty said:
I worked in chrysler dealerships for years back in the era, and thermoquads have a tendency to warp the plastic fuel bowls. Especially if the screws work loose. I'v replaced a lot of fuel bowls on these over the years. I remember it was a big problem with the lean-burn era cars, ( cordobas etc.) Many times you can sand them flat if there not warped bad, but that usally not the case. Most of the time the idiling problems come from two small round gaskets down in the fuel bowl that leak. I just rebuilt the one on my Lil red express, as they were leaking. Runs great now.
Click to expand...
these seals are num 6 on the chart these can cause a problem . a easy fix is sbc valve seals
 
70aarcuda said:
if it the original carb..put it in a plastic bag and box for future restoration...the 71 TQ cores are expensive these days..
Click to expand...


why for a future resto and not his currant one ? parts wont get easier to find later.
 
You must log in or register to reply here.
-

Back
Top