Re: Thermo-quad Tips
 

Just out of curiosity, who can do a decent restoration on a stock Thermo-Quad carburetor. I picked up an original 73 340 Duster and the car currently has a Holley carb on it and the original Thermo-Quad was in the trunk for obvious reasons. The car sat for about 15 or so years. I checked the plugs, cap, rotor etc. put fresh gas and a fresh battery in it and the car lit off with little issue. It ran and idled remarkably well with great oil pressure. I would like to get the Thermo-Quad done by someone who knows the tricks to make it work for street use and make it look half way decent to the eye.

Re: Thermo-quad Tips
 

Brad Van Lant or George Thompson are outstanding carb builders!

Really optimizing the jetting/Air Door/Accel. Pump are all the tuning
a street car requires. Try different settings and working to find out what the vehicle likes.

Use Air Bleeds to get best idle quality is something we probably all know to do.

Re: Thermo-quad Tips
 

Go to Moparts.com web site type in Scott Smith in search engine. He does fantastic work and is what you are looking for in a street engine application.

Re: Thermo-quad Tips
 

Hi.last weekend at dyno have problems with thermoquad i have 2 fresh race carbs and both same thing.when secondary opens and dyno puts load against motor it dies test tifferent fuel press and bigger secondary jets nothing different.I but 750 vacuum holley it screams to 7000 rpm no problem at all..any tips.thanks and greetings from finland.

Re: Thermo-quad Tipsk on these
 

Increase Air door Tension.

Work with Air Door Opening amt.

I am assuming carbs are put together correctly and floats
adjusted to specs.

Several books on these carbs still available.

If you supply Carb #.....I can give some jet suggestions
and Air Door starting openings.

Sometimes you get carbs that just do not work worth a *****
no matter what you do with them.

Re: Thermo-quad Tipsk on these
 

9800S?


Thank you!

Re: Thermo-quad Tips
 

.074/.075 primary (Holley) no metering rods

.143 Sec. with .790 Air door
OR
.137 sec with .750 Air Door

(Stock unmodified Air Door specs.)

3 turns on Air Door spring tension

These are conservative but will be good baseline in my opinion.

Do not modify emulsion tubes!

9800 Series are excellent carbs to start with.....a replacement carb
calibrated better than the factory installed stuff.

Re: Thermo-quad Tips
 

Thank you sir! I will swap my .149 secondary jet for one of your recommendations.

Are Thermoquads sensitive to fuel pressure? (I usually run 5.5 psi)

Re: Thermo-quad Tipsk on these
 

My thermoguad number is 6545s and second is vin 6453S thanks

Re: Thermo-quad Tips
 

Is your Duster 340 ( High or Low Comp.) or 360.

They have different size primaries (1 3/8 vs 1 1/2).

I will research these carb # and make sure correct for

vehicle as well.