Help dismantling ThermoQuad

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midnight340

midnight340

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following the Carter book step by step, removed all 10 screws, lifted top off. Book says carb phenolic resin bowl can now be lifted off the base. But it is very stuck.

I won’t pry on it of course! I held it by the bowl and tapped on the corners of the base ...firmly but gently with small hammer. No luck. So I soaked the joint with WD-40 in case that would soften the gasket. Still stuck.

Any other tips?? Am I missing something??
 
perhaps, though unlikely, somebody glued them together.
there are 4 locating pins on the bottom of the bowl which engage 4 holes in the throttle body base. So you want to be careful to not break those off. I would keep soaking it with solvent, not carb cleaner, and occasionally while holding the bowl right side up, tap(judiciously) downward on the carb throttle body base corners with a small copper, or other non marring hammer until it releases.
 
DFX 340 Duster said:
@RustyRatRod created a “how to” article regarding disassembly and reassemble of the TQ
Thermoquad Teardown and Reassembly How To
Click to expand...

Thanks I hadn’t seen that how-to, and thanks to @RustyRatRod for doing it!!!

rustycowll69 said:
perhaps, though unlikely, somebody glued them together.
there are 4 locating pins on the bottom of the bowl which engage 4 holes in the throttle body base. So you want to be careful to not break those off. I would keep soaking it with solvent, not carb cleaner, and occasionally while holding the bowl right side up, tap(judiciously) downward on the carb throttle body base corners with a small copper, or other non marring hammer until it releases.
Click to expand...

OK, I’ll just keep soaking with the WD-40. I’ll get it eventually, haven’t tried it this morning yet.
 
Soaked further with WD-40 and it finally let go.

Working on the 6518S "440 Industrial" carb first. Looks to have the same rods and main jets as is listed for the 6319S '73 340 carb, so I shouldn't be too far off. Not sure about secondaries yet.

I already has brass floats, so I assume that means it was rebuilt before?

Does anyone know what the "Industrial 440's" were used for? (Irrigation pumps and grain harvesters come to mind, being an old farm kid.)
 
I’ve heard there in them big trucks, 6 wheeled 16 ft. box truck, HD pick ups.
 
316D9F5B-6A7F-409F-8649-73566030A3D7.jpeg
The “Industrial” 440 may also be what went into motorhomes...?

The rods measure at 67/57/45. They have a 45 section but the 57-67 is a taper rather than two steps. Just curious, is this how all TQs are? These are stamped as #1930 which I don’t find on any listing. There is another # listed with the same diameter steps.
 
Some industrial motors ran at a fixed rpm. I’d check the throttle blade opening. Make sure the primary’s open 1/2 way or so before the secondary’s come in. Some are set up to open simultaneously. Most of the metering rods are two step. The ones in that carb seem to be different.
 
good call on the step up rods. They could be designed for a steady RPM and have little transition metering built in. also probably lacks every emissions trick they had going. C.A.P Carters had dimpled step up piston covers and a 3 step rods for cleaner transitional metering. These carbs may have the opposite engineering.
 
As I assembled it, all adjustments were pretty spot on. I checked everything. It had brass floats, and indications someone had rebuilt it not too long before it’s lengthy storage

For now I’ll use an adapter Later when I have the LD340 off I’ll modify it. Is the Mr. Gasket adapter as good as any?
 
midnight340 said:
For now I’ll use an adapter Later when I have the LD340 off I’ll modify it. Is the Mr. Gasket adapter as good as any?
Click to expand...
Pretty much, for the most part, there all the same. I used the Mr. Gasket on before. It was fine enough for the job.
Use the gasket to open up the LD-340. I had one with the MP mods.
:thumbsup: I sold it to a member here. I forget who but they should be having a hoot with it. I did!
Find an OE style gasket to under the carb and not the thin 1/16 kind. The OE style is thick and insulates the carb from heat.


gm1236 said:
Some industrial motors ran at a fixed rpm. I’d check the throttle blade opening. Make sure the primary’s open 1/2 way or so before the secondary’s come in. Some are set up to open simultaneously. Most of the metering rods are two step. The ones in that carb seem to be different.
Click to expand...
I e never seen a mill designed to operate at a constant rpm equipped with a 4bbl. A 2bbl. YES!
This was probably a motor home or heavy truck carb.

pishta said:
good call on the step up rods. They could be designed for a steady RPM and have little transition metering built in. also probably lacks every emissions trick they had going. C.A.P Carters had dimpled step up piston covers and a 3 step rods for cleaner transitional metering. These carbs may have the opposite engineering.
Click to expand...
I e never seen a TQ with a raised metering rod cover.
Nearly ALL TQ rods are 3 step. I would have to open up my race TQ again to verify those are two step.
81A3E5ED-800E-4E7D-A51E-3F94D2892909.jpeg
64918AA0-0C2A-4379-8A01-9F793E90788B.jpeg
ED9DFB9C-C103-4880-9C8E-DF57ECEFF8E4.jpeg
5674A0B8-37FE-4D7C-A71E-3A36D19D8E74.jpeg
 
C.A.P. carter AFB's ala '65 had the raised dimple 3 step rods.
 
Yep! The AVS line had three step metering rods and raised covers to fit them.

The TQ’s have flat non raised covers for the rods. Although still exposed.
 
pishta said:
C.A.P. carter AFB's ala '65 had the raised dimple 3 step rods.
Click to expand...
Not just the C.A.P. ones...most early factory AFB's had the 3 step rods and dimpled covers. I have several early 60's to late 60's factory AFB's on the shelf and they all have the 3 step rods and dimpled covers.
 
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