Thermoquad jet and rod change

Sonny · Dec 30, 2018

It looks like I can replace the rods from the top by removing the choke link and screw/bracket. Is removing the top of this TQ to get to the primary jets any worse than removing jets in a new Edelbrock? Is there anything that I need to know before taking the top off? At idle my mixture screws are 10 (1/2 turns) out and still have 18 to 19 air fuel ratio in gear. Try’s to cut off at a light from being too lean. When I lift up on the rod bracket while running, the air fuel ratio improved greatly.

khryslerkid · Dec 30, 2018

I'm not a TQ expert but there is a lot of info and videos on the net on rods, jets, springs. Google "Thermoquad" and have at it.

Sonny · Dec 30, 2018

So I took the carburetor apart. Was pretty simple much like an Edelbrock. Good news is my jets are 100s. The rods are number 2110. I basically need new rods that the thickest part of the new rod is the same diameter as the smallest part of the 2110 at the bottom of the rod.

Sonny · Dec 30, 2018

Just to put an end to this thread, and thanks for all the advice, I did the ultimate no no. I took those jets and drilled them out and guess what. It purrs like a kitten at 14.0 air fuel ratio and no more idol hesitations or cut off’s. Thanks again for all the help.

Dana · Dec 30, 2018

What size drill bit? Where are you're idle mixture screws now?

Sonny · Dec 30, 2018

Dana said:
What size drill bit? Where are you're idle mixture screws now?

The bit was just barely larger than the hole. Could’ve almost turned it by hand. Turned the screws in 4 half turns then fired it up and had about 13 af ratio. Will probably go even more. I was so happy I didn’t even turn them any more lol. Vacuum was a nice steady 15.

idrivemopar · Dec 31, 2018

You do know that you can purchase new jets and rods, 1966 and 2127 rods are available, and jets up to .105 are available. Also, you mentioned that when you raised the "rod bracket" it ran better. That is the step up valve and you can adjust that valve, just don't forget how many turns in or out you made in case you need to set it back. There is a procedure to make sure its set to factory adjustment.

here is the link to get thermoquad parts
https://quadrajetparts.com/carter-thermo-quad-carburetor-c-299_158.html

Sonny · Dec 31, 2018

idrivemopar said:
You do know that you can purchase new jets and rods, 1966 and 2127 rods are available, and jets up to .105 are available. Also, you mentioned that when you raised the "rod bracket" it ran better. That is the step up valve and you can adjust that valve, just don't forget how many turns in or out you made in case you need to set it back. There is a procedure to make sure its set to factory adjustment.

here is the link to get thermoquad parts
https://quadrajetparts.com/carter-thermo-quad-carburetor-c-299_158.html

Thanks! I looked there yesterday and their rod selection was only 2 sizes. A few more jets. I will look into that spring adjustment too!

idrivemopar · Dec 31, 2018

Here is the info on the metering rod adjustments.

There are many metering rod combinations and while the perfect scenario would be to have as many different sizes as possible, one particular size(#stamped on the metering rod lengthwise)# is the best all-around. This # is the 1966 metering rod. Since metering rods will only show a marginal performance increase, the metering rod # is not as critical as the actual piston height adjustment:

with the fast idle cam not engaged, find the metering rod piston's center slot on the top of the piston center and with a small slot head screwdriver, lightly bottom the piston and turn the slot counter-clockwise until the piston stops dropping, then turn the slot clockwise noting exactly when the piston starts back up, still lightly bottoming the piston, turn the slot 1 turn clockwise. This is the correct way to dial-in the metering rod tree/piston. For a richer setting, turn the slot 1/4 more at a time. For a leaner setting, back off the slot counter-clockwise 1/4 turn.

rumblefish360 · Jan 1, 2019

@Sonny Congrats on a victory on the risky gamble of drilling the jet. FWIW, I have bent a AFB rod 3/4 of an inch shorter to match the TQ rods length, cut the extra off and made use of it just fine.

Sonny · Jan 1, 2019

rumblefish360 said:
@Sonny Congrats on a victory on the risky gamble of drilling the jet. FWIW, I have bent a AFB rod 3/4 of an inch shorter to match the TQ rods length, cut the extra off and made use of it just fine.

Oh wow nice tip! May have to try that!

pentahead · Jan 1, 2019

Congrats!

Thermoquad jet and rod change

Sonny

It’s all fun til the rabbit gets the gun.

khryslerkid

FBBO Gold Member

Sonny

It’s all fun til the rabbit gets the gun.

Sonny

It’s all fun til the rabbit gets the gun.

Dana

Active Member

Sonny

It’s all fun til the rabbit gets the gun.

idrivemopar

Well-Known Member

Sonny

It’s all fun til the rabbit gets the gun.

idrivemopar

Well-Known Member

rumblefish360

Well-Known Member

Sonny

It’s all fun til the rabbit gets the gun.

pentahead

Well-Known Member

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