I been fukkin' around with TQ's for 40 years. Quad rings and air door tension adjustments are always required. Once you get one to run, they will out perform a lot of other carbs.
Uncle Tony: “This carburetor cracked for no reason” Me: thinks back to the hundreds of times Uncle Tony has literally thrown carburetors across the yard.
I've got dozens of TQs and the only cracks I've seen are when there was a fire inside, and even then they didn't seem to affect how the engine runs, just cosmetic little cracks.
I might know a thing or 2 about basic Thermoquad adjustments but before all that, I'd fuck off those brass floats. When old they're nothing but trouble. Put new nitrophyl floats in with new needles and seats. Float adjustment: Turn air horn assembly upside down and with the gasket on, the measurement from the very lowest point (highest point when upside down) on the float to the gasket surface is 23mm. Bend the arm in the usual manner. Secondary air door adjustment: Hold air door wide open against stop. Measure the gap between the edge of the secondary air door to the air horn wall. Adjust by bending the secondary air door tab to 12mm. Secondary air door spring adjustment: Loosen the lock screw until it falls open fully. Turn the adjuster screw until the air door just contacts the the closed stop and turn a further 1.25 turns. Naturally everything has to be free and not in any way sticky to get the preload correct otherwise the spring'll be too heavy and it could surge in the true sense ie (the secondaries will come on cleanly but suddenly at a too high rpm without a smooth transition so nothing then all) . Secondary choke dash pot adjustment: Retract dash pot with vacuum and bend rod until there is 1mm secondary air door movement with the dash pot still retracted. As you pointed out this is a super critical adjustment. The dash pot has to hold vacuum indefinitely otherwise get another one. **Also the accelerator pump is supposed to squirt when the secondaries open and almost no one knows this. This is how to set it up so the accelerator pump gives two shots ie one for the primaries and one for the secondaries. Part 1. Primary accelerator pump adjustment: Back off throttle stop screw fully then after just touching the cam screw it in 1/2 a turn. Measure the distance from the bottom of the 'S' link to the housing. It should be 9mm. Bend the pump rod to adjust. Part 2. Open the primaries until the point the secondary throttle valves begin to open (but don't). Measure the distance from the bottom of the 'S' link to the housing. It should be 4mm. Bend the tang that is near the bottom of the accelerator pump rod where it connects to the primary shaft. It is the tang that is at 90 deg. You'll see it. When the secondary throttle valves are wide open the 'S' link should rest on the housing. If you can't attain this adjustment then the accelerator pump plunger is too short. They are incorrectly listed in parts catalogues. If you have a few old Thermoquads pull them apart and it often seems they all have different length accelerator pump plungers in them. The key is 9mm 'S' link height in Part 1. If you can't get that then the plunger is incorrect! The initial adjustment for the primary metering rod height: With primaries held closed, push the metering rod 'T' down. With a small screw driver find the bottom position then screw the piston up 1.5 turns. Those initial adjustment procedures will get everything back in the ball park. Also when all this is done I have found the secondary dash pot restrictor becomes less important.
I've got one on the demon thermoquad knock off in my 69 Buick. I like "whore air cleaner" better ;) Had to bang a dent into the underside to clear the accelerator pump. #techtip 🤘
True, I NEVER EVER seen one that bad . Most times a little WD40 and a tooth brush cleans them up pretty good if you don't leave them out in the SNOW for 3/4/5 years lol .
There are a ton of interrelated adjustments on a Thermo Quad. There is a slotted adjustment for the air door secondary that tightens and loosen s how quickly the secondary door opens. The choke pulloff mostly does the choke blade opening just as the car starts so it will idle right. I believe this pulloff also releases the secondary door when the choke goes open. You can also physically tweak the split halt of the secondary blades to get more or less angle to make it pull more open or closed to help with getting the back mixture right. If you get the tension adjustment right on the top drivers side of the upper body it will tweak in the opening speed. Chrysler used to sell a special adjustment tool for that. It has a metal tube with notches that fit the outer lock ring, the you slide a screwdriver through the tube with the tangs to hold it, adjust the inner slot from loose stop to maybe 3 turns of tension and see how it opens at wot. Not enough loosen it a bit, too much and bogging tighten it more. The metering rod tree thing in the centet on top can be adjusted too and controls how far and fast they move in the jets. Be careful with that one as you can go too far and it will catch and hang up at WOT. It's been a while since I have tuned one so I might be off on some of this but the factory based manuals give full alignment specs for what all the rods and tweaks are supposed to be stock and you can go from there. I had a Super Quad 9800 series after market TQ on the 318 in my Dart and it ran smoothly and didn't bog when I was done with it. The only time I had to mess with it after that was when the O rings went bad or a float sunk. The fuel transfer things do eventually fail and will need to be glued back on but I never had one do it while on the car. They run very hard and smooth when right, the work is getting them there.
@silverbird58 I have a strip kit and a Doc Fiberglass yellow custom made air door tool and probably 20 or so complete in the trunk of my Dart. Was moving and had to find a somewhat safe place to stash them till I got my shed built. They seem to be doing ok in there so they stayed. Used them on all v8 daily drivers we had back in the day. Driving a Neon coupe now, better on gas and not worth a lot if it gets destroyed.
@@69Dartman I have maybe 2 of Doc's "Electric Bananas!" I know I gave one to a friend in Murfreesboro. I have an original somewhere. And I have an original strip kit too. THERMOQUADS FOREVER!!!!
There is a specific setting for the spring on the secondary air valve. The opening rate is controlled by the vacuum diaphram leak down rate. The rate of leak down is controlled by the size of the hole in the vacuum port in the base of the carb. If you put too much spring tension on the secondary air valve you can mess w/ the secondary metering. Always control it by the diaphram leak down rate. This can be done by enlarging the hole in the vacuum connection. This will let the secondaries open quicker but only do this as needed.
@@larryhutchens7593 Well I was always told it was in that adjustment and that is what I used. I would tweak it till everything rolled in smoothly but I know the pulloff is tied in too. Well ya learn something every day and the Dart is retired in the backyard now, plus the accelerator pump wasn't working last time I drove it from sitting too long so I couldn't enjoy driving it to the new house. Carb needs to be rebuilt and the transfer tubes fell off so have to reglue them or replace the main body as I have a bunch. I haven't looked at the book I have for it in a long time so might have forgotten some of the steps and tweaks. I have a brand new 9800 missing the choke plate but I think it's too nice to waste on getting the Dart going again with the crap gas that's in it now.
Warning ! warning ! A helpful tip . I've also rebuilt many thermoquads . Only use a white 2 part epoxy that come in a little white plasic bottle with white metal cap called Marine Tex ! You can buy it on amazon . To glue the caps back on you will have to clean and lightly sand the surfaces that the epoxy bonds to so the epoxy will seal those fuel caps back on then let it set for a few days to properly cure. The Marine Tex is the only epoxy on the market that passed a 4 day test submerged in gasoline! The carb never came apart!
Uncle Tony I love your videos and have learned a lot from you besides being reminded of a lot I have forgotten. However, that choke pull off is NOT how you’re supposed to adjust your secondary air valve opening. The adjustment is on the driver’s side. You control how fast it opens with a set screw and a lock. Chrysler used to sell and adjustment screw but I always used a couple of flat head screwdrivers. Also, where on earth have you had those carbs? I have probably 10 on the shelf and all move and are in buildable shape. As a side note, I daily drove a 400 Cordoba with one of those for years back in the 90’s and would get 17mpg or a little better on the highway. They are great street driving carbs.
As I recall, there is a secondary adjustable spring tensioner that can be adjusted by loosing a small screw and turning more or less tensioner on the secondary top butterfly then locking it with the small screw. I know that's the way it works on a 1000cfm 4848SA TQ I always had good luck with them except jetting can be a total nightmare but worth it. Don't give up, look for that secondary butterfly tension adjuster, it's small, but it's there. Shoot if a low life Chevy guy can make a TQ work on a Pontiac it should be no sweat for you. lol . :)
@@skiz8848 He may have. Will have to go all the way back to the General Mayhem episode. But Freiburger says it to Dulcich all the time on Roadkill Garage. Because Dulcich loves the thermoquad.
@@Trikekid84 Back when these cars came out i never even herd of Edlebrock carb. I can only speak from what i saw in my area back in the day.Thermoquad were always being replaced by a Holley .
I liked the AFB. Easy to adjust. The Thermoquad was on a lot of cop cars I worked on in a Dodge dealership. We had very few issues with them. The 440 cop cars had very slow secondary opening from the factory, possibly on purpose. The cops would complain the cars were slow. Used to bend the link shorter on the vac actuator, like Uncle Tony showed. Cops loved it, but probably didn't make it any faster. Just seemed like it because of the quicker change in sound.
I’ve Always had good luck with thermoquads. I just built 3 a couple of months ago. I put one on a fifth avenue once and power and fuel economy was vastly improved. Good cores are getting harder to find though
Thanks uncle Tony. My late grandfather, a Mopar man, could tune the hell out of a Thermoquad. Nice to see you sharing some of the tips he taught me. He could also make a Rochester Varajet run great too. I'd love to share some stories about our travels in his '66 Polara coupe while towing his 35' Spartan trailer. Good memories. Except for the time we replaced a piston on the side of US321 because he had it jetted too lean. Sucked at the time, but a great memory!
I had many low 10 second cars in the day using Thermoquads great carbs BUT they are unforgiving you have to get them set right not much in between room with them. When Carter sold out I contacted them about buying all their jets springs and metering rods they had. Also some tooling for parts for those carbs a deal was made THEN a divorce wiped me out so the deal never happened. I still have about 15 or 20 of them in the garage a few still new in the box never opened in sealed plastic. I plan on build a 9.90 small block duster using a themoquad using all old school parts remember Direction Connection? if you follow their parts lists for the et you want to run you will hit the numbers.
The Holley rebuild kits have resin impregnated gaskets and the float bowl gaskets have xs material that I would use for the TQ O-ring seals by using a hole punch kit. So find suitable material and make your own, the carb comes apart with no ripped gaskets if you're lucky/careful! And there is a spring tension setting on the TQ secondary air valve too as well as the primary metering rods.
I like Thermoquads, specially early 70`s and competition series, I can rebuild them well. On Thermoquads all parts are outside and easy to see and tune by hand and I can tune them very fine for each RPM and each condition, I put it on Buick 455 stage 1 and with them I changed the engine to specs that I want, How to cold start, how to Idle, how to accelerate and jump, etc. Everybody shocking when they find out I use Thermoquads but I guess my mind can understand them or maybe Thermoquads like me.
By looking at that Carb it was full of water at some point then froze blowing the body apart, I know they fail but that's what it looks like happened here.
The adjustments on the Thermo quad have to be done in the order that they are listed in the repair manual or the repair instructions. If you look at the vacuum connection on the base of the carb you will notice that there is a built in restriction there. I've not worked on a tremendous lot of these but all the ones I have (about 15) have a restriction at that point. I'm assuming that the factory built the carbs to work correctly on only 1 engine & not meant to be modified. On Q-jets the restriction is in the vacuum diaphram itself. You can use a fish tank air adjustment device to regulate the opening rate of the secondary air valve. That corroded carb you have looks like it was left out in the weather for a few years. I've had some in my shop for over 10 years w/ no corrosion at all. On that little o-ring seal that goes in the bottom, I've assembled carbs & forgot to put those in. Talk about running pig rich. Another mistake i've made is using a Q-jet base gasket on a Thermo-quad. Look almost identical but you will end up w/ a gigantic vacuum leak. I have been buying my kits from Mike's carb & have been having trouble w/ the accel pump material when using gas w/ ethanol. The material will soften & get removed from the plunger. Contacted Mike's & he said that he is having trouble getting them made of a material that will hold up. I'm thinking of putting a shut off valve in my duster so that I can run the carb dry when I park it since it isn't driven much. Just passing on some hard learned info.
Uncle Tony , Most people would say throw that freaking carburetor in the trash , but I do give you credit you stayed with it and you made it happen... as you know it would’ve been easier to put a Carter wfb on there would’ve had the same linkage.. bakalite for a carburetor midsection might’ve seemed like a good idea at the time...
grumble grumble grumble Just did my 83Riviera fuel pump! Turns out original! Then my accelerator pump goes! Time fer a Carb rebuild! Pain, in the ascot^__~ At least we're not alone ^__^ ha ha ha THNX!
I thought the pull off should hold the door closed not tight but closed. The Quadrajet, we would glue the orifice on the pull off and drill it small amounts till it would slightly bog then re-glue and drill to the size the hit the best. Had to make sure the opening spring was set to specs also. Don't let them talk you out of it.
Aloha Uncle Tony I just picked up one of my best finds today… 10 years in temp controlled garage.. A 1967 4spd Charger with 30k original rust free miles… The find came with an extra 1958 392 4bl Hemi crate motor and 40 boxes of nice charger parts and 1/2 of the boxes being nice TQ carburetors. I believe the car currently has a 383 with radiator and carb pulled. Would love to get a phone consultation. I really wouldn’t mind paying for your time. Mahalo 🙏 Jim
Most all of that info on the carb is wrong. Most have no clue when it comes to working on this carb. It needs very little adjustment to work on any car and most tinker with it without knowledge till it wont run right on any engine. There's three version. 800 cfm small block, 850 cfm big block and a 1000 cfm competition series designed for the Hemi but was never used on factory cars. Could be bought over the counter though. The bowls don't crack or bust unless it's got water left in it to freeze from improper storage. The jet wells will come loose with age and cause it to flood, but it's an easy fix with some two part epoxy that is fuel resistant. No big deal. That choke pull off is just that a choke pull off. It has nothing to do with secondary door timing and does not require any restriction at all. It will cause it to not work right if you restrict vacuum to it. That S link is for adjusting the choke pull off only. It will effect the secondary lock out when the engine is cold as well. On our race carbs all of the choke linkage, blades, and pull offs are discarded. So that alone proves this pull off has nothing to do with the secondary adjustments other than the lock put. You can do a minor adjustment by bending the secondary door tabs to make it run richer or leaner. There is a tab on the drivers side that changes how far the door can open and most all need to be upright when running at WOT or you wont get it's full potential. The timing of the secondary door is controlled by spring tension only. It can be adjusted on the drivers side. It has a locking screw that you can use a larger flat screw driver to loosen or tighten it. The smaller flat head screw behind that locking screw adjusts the spring tension on the secondary doors. tighten it to slow the door opening preventing a bog or loosen it for a faster door opening. You want it to be as loose as possible without it bogging at WOT. There is a small screw behind the choke tower you can use to fine tune idle and off idle fuel mixture. Just turn the screw to raise the tree and it will be richer, lower the tree with that screw to lean it out. You can buy or order a rebuild kit from any autozone, advance auto, napa or even summit racing. You can also buy new carbs from Summit Racing and others. I just looked at one on Summit Racing recently for a 74 440 and it was 212 plus a core charge if you don't have one to trade in. Best carb ever made and when set up right, there's no other carb out there that can touch it.
Northumberland Post exactly! I’m a little disappointed with how Uncle Tony responded to all of us who commented about the air valve adjustment. Nobody’s perfect though.
Those Thermoquads can be a pain in the butt, but once you get one set and tuned right - it can be a very forgiving carb. The (2) 850cfm big block versions I put on a tunnel rammed 498cid engine back in the early/mid 90's took a couple weeks to get set right, but once I got needles, jets, and secondary air door tuned right - that thing was a BEAST. AND, didn't get all that bad fuel economy for 650+ some-odd dyno'd horsepower(tuned for street gas, hotter drag strip timing had more power but needed track fuel). I picked the TQ's because of Tampa FL's hot temps. ...well, that and I got them dirt cheap at a "you pull-it" parts yard. The local speed shop up in Temple Terrance was able to get me rebuild kits and jet/needle kits.
Jordon Cloutier Frieburger would wear out his welcome after the 1st 5 mins of tinkering . . . the guy is incapable of not spilling huge messes of ATF & coolant, sometimes both in one mess at the same time.
Something you may want to look into. I started having issues with my Quadrajet and being I didn't want to spend much, I bought a Street Demon 1900 from the parts store. It was the cheapest carburetor they had at about $320. It's a 625cfm designed around the Thermoquad and AFB by looks, but as a 3 barrel design. It is a fantastic carburetor. Fires right up hot or cold, daily driver application, absolutely perfect all around. I was skeptical at first because of the low price and the chrome shine, but I don't know if I'll ever buy anything different. It's as good on gas as my Quadrajet was and plenty of power.
here is proof that even an expert can be aggravated by a carburetor! I've lost a few battles with carbs and took them to experts to sort out the problem. thanks for the video tony.
The upper flap is adjusted on the other side. It is spring tension adjustment screw with a lock ring. There used to be a special tool to unlock while you hold the inside screw. But you can take a big enough screwdriver to loosen the lock ring while using a smaller screwdriver to adjust the tension. More tension will cause the upper flap to open slower. It doesn't take much. Don't forget to tighten the outer lock ring. I can take a TQ from a 440 and place it on a 318 and with a little adjustment, it will run great.
Just want to say thanks again for the videos. Im currently gathering parts for my trans am. At first i was all gung ho to do an ls swap. Now....im putting together a mild 455. Cleaning parts and making it look as good as it runs is way more time consuming i think. Thanks again, cant wait for the next video
I know I should play with Holley but I love the thermoquad secondary sound. I have a rebuilt one on my truck and it bogs, now I know why. Thank you Uncle Tony! 😂
The bog is from the air door tension adjustment. That choke pull off is not your problem. It just keeps the secondaries from opening before the choke does and the engine isn’t warmed up.
Knowing that the carb master had to take a carb apart a couple of times to get it right makes me feel a little better about needing two tries to get my old AFB correct. My old man used to hate that Thermoquad, I never really knew what he disliked about it until now.
Thanks Tony - great info, as usual! I've driven two Thermoquads extensively - a new 360 4-speed that worked perfectly with occasional cleaning/minor adjustment and a way used 400 lean burn automatic that worked very well after being rebuilt by a "cash only" place in Trenton, NJ. I'd never heard of a vacuum restrictor to control the secondaries; so, how did the factory get it to work properly? Thanks.
George Wetzel they don’t use a vacuum restrict or. There secondary air door is spring loaded, and the spring tension is adjustable just like the new street demons. Uncle Tony had a brain fart on this one.
I’ve never had a thermoquad but have had a few holleys in my time,with this car I decided to try the edelbrock and I’m glad I did! The tunability on this as opposed to the holleys I’ve had is by far better AND it doesn’t keep going out of tune!
got 3 good 850 truck thermoquads 1 1/2 in primaries you kick in the secondaries its just like a passing gear and you can watch the gas gauge drop just as fast but the sound of the 440 big block is like no other
Hell, I slapped a Thermoquad on a dead stock 77 Diplomat 318 w/2.71 gears and stock single snorkel air cleaner in the early 90's. Ran with a late 80's Fox body from 55 - 100 MPH.
I’m thinking it needs a mass, wideband, direct injection, variable valve lift and cam phasing standalone management. May as well toss in a pneumatically shifted sequential manual transmission. 😁
Tighten the spring and bend the tab the bog will be gone and it will fatten right up. Those that don't understand a thermoquad send all your money directly to Holley
back in the 80s where I worked, the mechanics would swear at the thermo quad. often they would be draw filing the resin bowl to get it to match and stop leaking when assembled.
Hey man I just had a quick question for a mopar guy,I have a 76 charger, I'm looking for tubular uca/lca everything I find says 62-74 b body but I can't find nothing for 76 b body, ( I bought some door handles that were advertised for 72-74 but the worked fine, my point is is this a mislabeling since the 75-78 chargers are not desired or is there a change in the b body platform that will make these lca/uca not fit
Uncle Tony, please take us to Carburetor Land on our next vacation! Who needs Disneyland anyway... We have Small World in Carb land: Italy: Webers, England: SU, etc. Cheers
I like Carter four barrels, I had one back in the day with mechaniacal secondary's on my Chevy. Did haven't have plastic part in it. Is it the same carb?
Oh look, I found the inexperienced, snotty, just plain dumb millenial comments that show how ignorant they actually are. There's always at least one... I bet neither of you have ever touched gasoline, let alone a carburator that's as old as your parents. btw, I am using a 6 year old samsung. It works better and gives me less trouble then newer phones.
Bud, I really hope you read this. By no means you will change your carb, right? Ok. Find the spring and the adjuster on the secondaries. Its like the obes on a rochester. Allen, etc. You dont need a 750cfm carb on it, but you can do it adjusting the tension on those springs. Ive did it once before. But 20mpg? Not even dreaming
I know what you mean, I've always proudly run Q-jets on my trucks and stocked up on several spares over the years, only to find that I had the same problem as Tony. Moisture got to them, rusted the bowls and throttle plates, though not as bat as Uncle Tony's thermoquad there. I recently broke down and started looking into spreadbore Holley's for replacements... :(
I been fukkin' around with TQ's for 40 years. Quad rings and air door tension adjustments are always required. Once you get one to run, they will out perform a lot of other carbs.
Uncle Tony: “This carburetor cracked for no reason”
Me: thinks back to the hundreds of times Uncle Tony has literally thrown carburetors across the yard.
🤔....... I always believed them to be "stunt" carbs thrown into a bunch of cardboard boxes or old mattresses hahaha.. or CGI...
looks like it froze from all the water that must have been in it judging by the corrosion on the other parts.
O fuck .... No shit Haha carburetor shot pull
Michael Lehmann well the thermoquad was known for warping I’d guess after a while it’d be only natural to have it crack
I've got dozens of TQs and the only cracks I've seen are when there was a fire inside, and even then they didn't seem to affect how the engine runs, just cosmetic little cracks.
I might know a thing or 2 about basic Thermoquad adjustments but before all that, I'd fuck off those brass floats. When old they're nothing but trouble. Put new nitrophyl floats in with new needles and seats.
Float adjustment:
Turn air horn assembly upside down and with the gasket on, the measurement from the very lowest point (highest point when upside down) on the float to the gasket surface is 23mm. Bend the arm in the usual manner.
Secondary air door adjustment:
Hold air door wide open against stop. Measure the gap between the edge of the secondary air door to the air horn wall. Adjust by bending the secondary air door tab to 12mm.
Secondary air door spring adjustment:
Loosen the lock screw until it falls open fully. Turn the adjuster screw until the air door just contacts the the closed stop and turn a further 1.25 turns. Naturally everything has to be free and not in any way sticky to get the preload correct otherwise the spring'll be too heavy and it could surge in the true sense ie (the secondaries will come on cleanly but suddenly at a too high rpm without a smooth transition so nothing then all) .
Secondary choke dash pot adjustment:
Retract dash pot with vacuum and bend rod until there is 1mm secondary air door movement with the dash pot still retracted. As you pointed out this is a super critical adjustment. The dash pot has to hold vacuum indefinitely otherwise get another one.
**Also the accelerator pump is supposed to squirt when the secondaries open and almost no one knows this. This is how to set it up so the accelerator pump gives two shots ie one for the primaries and one for the secondaries.
Part 1.
Primary accelerator pump adjustment:
Back off throttle stop screw fully then after just touching the cam screw it in 1/2 a turn. Measure the distance from the bottom of the 'S' link to the housing. It should be 9mm. Bend the pump rod to adjust.
Part 2.
Open the primaries until the point the secondary throttle valves begin to open (but don't).
Measure the distance from the bottom of the 'S' link to the housing. It should be 4mm. Bend the tang that is near the bottom of the accelerator pump rod where it connects to the primary shaft. It is the tang that is at 90 deg. You'll see it.
When the secondary throttle valves are wide open the 'S' link should rest on the housing.
If you can't attain this adjustment then the accelerator pump plunger is too short. They are incorrectly listed in parts catalogues. If you have a few old Thermoquads pull them apart and it often seems they all have different length accelerator pump plungers in them.
The key is 9mm 'S' link height in Part 1. If you can't get that then the plunger is incorrect!
The initial adjustment for the primary metering rod height:
With primaries held closed, push the metering rod 'T' down. With a small screw driver find the bottom position then screw the piston up 1.5 turns.
Those initial adjustment procedures will get everything back in the ball park.
Also when all this is done I have found the secondary dash pot restrictor becomes less important.
I see the problem. the carb has been sitting at the bottom of the ocean too long :)
Pulls carburetor out from swamp since Reagan was Presedent. See, this is poor quality aluminum.
This was great lol! WINNER
He found it in the bottom of a scrap metal barrel at the marina. Sea salt is good for you not your carb.
You are all wrong. That Thermoquad was actually salvaged of the Titanic.
"princess air cleaner" ! love it.....you just ripped on half the guys watching .....:)
I've got one on the demon thermoquad knock off in my 69 Buick. I like "whore air cleaner" better ;) Had to bang a dent into the underside to clear the accelerator pump. #techtip 🤘
area51tone nice
Damn, gonna spray mine matt black now!
Flip the air cleaner lid on a Thermoquad equipped car and it’s got to be one of the loudest carbs ever made! Lol
If you're going to screw around with a Thermoquad don't store them in a swamp ;)
True, I NEVER EVER seen one that bad . Most times a little WD40 and a tooth brush cleans them up pretty good if you don't leave them out in the SNOW for 3/4/5 years lol .
There are a ton of interrelated adjustments on a Thermo Quad. There is a slotted adjustment for the air door secondary that tightens and loosen s how quickly the secondary door opens. The choke pulloff mostly does the choke blade opening just as the car starts so it will idle right. I believe this pulloff also releases the secondary door when the choke goes open. You can also physically tweak the split halt of the secondary blades to get more or less angle to make it pull more open or closed to help with getting the back mixture right. If you get the tension adjustment right on the top drivers side of the upper body it will tweak in the opening speed. Chrysler used to sell a special adjustment tool for that. It has a metal tube with notches that fit the outer lock ring, the you slide a screwdriver through the tube with the tangs to hold it, adjust the inner slot from loose stop to maybe 3 turns of tension and see how it opens at wot. Not enough loosen it a bit, too much and bogging tighten it more. The metering rod tree thing in the centet on top can be adjusted too and controls how far and fast they move in the jets. Be careful with that one as you can go too far and it will catch and hang up at WOT.
It's been a while since I have tuned one so I might be off on some of this but the factory based manuals give full alignment specs for what all the rods and tweaks are supposed to be stock and you can go from there.
I had a Super Quad 9800 series after market TQ on the 318 in my Dart and it ran smoothly and didn't bog when I was done with it. The only time I had to mess with it after that was when the O rings went bad or a float sunk. The fuel transfer things do eventually fail and will need to be glued back on but I never had one do it while on the car. They run very hard and smooth when right, the work is getting them there.
@silverbird58 I have a strip kit and a Doc Fiberglass yellow custom made air door tool and probably 20 or so complete in the trunk of my Dart. Was moving and had to find a somewhat safe place to stash them till I got my shed built. They seem to be doing ok in there so they stayed. Used them on all v8 daily drivers we had back in the day. Driving a Neon coupe now, better on gas and not worth a lot if it gets destroyed.
@silverbird58 thank you!!!
@@69Dartman I have maybe 2 of Doc's "Electric Bananas!" I know I gave one to a friend in Murfreesboro. I have an original somewhere. And I have an original strip kit too. THERMOQUADS FOREVER!!!!
There is a specific setting for the spring on the secondary air valve. The opening rate is controlled by the vacuum diaphram leak down rate. The rate of leak down is controlled by the size of the hole in the vacuum port in the base of the carb. If you put too much spring tension on the secondary air valve you can mess w/ the secondary metering. Always control it by the diaphram leak down rate. This can be done by enlarging the hole in the vacuum connection. This will let the secondaries open quicker but only do this as needed.
@@larryhutchens7593 Well I was always told it was in that adjustment and that is what I used. I would tweak it till everything rolled in smoothly but I know the pulloff is tied in too. Well ya learn something every day and the Dart is retired in the backyard now, plus the accelerator pump wasn't working last time I drove it from sitting too long so I couldn't enjoy driving it to the new house. Carb needs to be rebuilt and the transfer tubes fell off so have to reglue them or replace the main body as I have a bunch. I haven't looked at the book I have for it in a long time so might have forgotten some of the steps and tweaks. I have a brand new 9800 missing the choke plate but I think it's too nice to waste on getting the Dart going again with the crap gas that's in it now.
Warning ! warning ! A helpful tip . I've also rebuilt many thermoquads . Only use a white 2 part epoxy that come in a little white plasic bottle with white metal cap called Marine Tex ! You can buy it on amazon . To glue the caps back on you will have to clean and lightly sand the surfaces that the epoxy bonds to so the epoxy will seal those fuel caps back on then let it set for a few days to properly cure. The Marine Tex is the only epoxy on the market that passed a 4 day test submerged in gasoline! The carb never came apart!
@silverbird58 I had a 79 351 Windsor Mercury Marquis that got 24mpg on a trip with that VV carb. Real PITA when it acted up.
Uncle Tony I love your videos and have learned a lot from you besides being reminded of a lot I have forgotten. However, that choke pull off is NOT how you’re supposed to adjust your secondary air valve opening. The adjustment is on the driver’s side. You control how fast it opens with a set screw and a lock. Chrysler used to sell and adjustment screw but I always used a couple of flat head screwdrivers. Also, where on earth have you had those carbs? I have probably 10 on the shelf and all move and are in buildable shape. As a side note, I daily drove a 400 Cordoba with one of those for years back in the 90’s and would get 17mpg or a little better on the highway. They are great street driving carbs.
As I recall, there is a secondary adjustable spring tensioner that can be adjusted by loosing a small screw and turning more or less tensioner on the secondary top butterfly then locking it with the small screw. I know that's the way it works on a 1000cfm 4848SA TQ I always had good luck with them except jetting can be a total nightmare but worth it. Don't give up, look for that secondary butterfly tension adjuster, it's small, but it's there. Shoot if a low life Chevy guy can make a TQ work on a Pontiac it should be no sweat for you. lol . :)
"Thermoquad, The carburetor that punishes you for trying to go fast." - David Freiburger
i thought finnegan said that in the RV
@@skiz8848 He may have. Will have to go all the way back to the General Mayhem episode. But Freiburger says it to Dulcich all the time on Roadkill Garage. Because Dulcich loves the thermoquad.
Thermoquad , the best friend Holly corporation ever had .
Cheef Cherokee meh. I wouldn't trade my carter for a holley for anything
You mean edlebrock right?
@@Trikekid84 Back when these cars came out i never even herd of Edlebrock carb. I can only speak from what i saw in my area back in the day.Thermoquad were always being replaced by a Holley .
I liked the AFB. Easy to adjust. The Thermoquad was on a lot of cop cars I worked on in a Dodge dealership. We had very few issues with them. The 440 cop cars had very slow secondary opening from the factory, possibly on purpose. The cops would complain the cars were slow. Used to bend the link shorter on the vac actuator, like Uncle Tony showed. Cops loved it, but probably didn't make it any faster. Just seemed like it because of the quicker change in sound.
Sweet daily Uncle Tony , I feel you should do a garage burnout . Cheers
I’ve Always had good luck with thermoquads. I just built 3 a couple of months ago. I put one on a fifth avenue once and power and fuel economy was vastly improved. Good cores are getting harder to find though
Yep I love the bad reputation, makes them cheap to acquire
Thats why ive got 11 of them in the shed
Hey Tony, it's mopar boy, I overhauled several Thermoquad. One on my parents 1977 440 dodge motorhome, and on my 1985 dodge ramcharger and others.
Thanks uncle Tony. My late grandfather, a Mopar man, could tune the hell out of a Thermoquad. Nice to see you sharing some of the tips he taught me.
He could also make a Rochester Varajet run great too.
I'd love to share some stories about our travels in his '66 Polara coupe while towing his 35' Spartan trailer. Good memories. Except for the time we replaced a piston on the side of US321 because he had it jetted too lean. Sucked at the time, but a great memory!
I'd still run Theremoquads if I could go back to 1975 and get fresh ones and a Carter Strip Kit.
What about the secondary air door adjustment on the driver's side of that Thermoquad?
Right! That's what I've always thought was the #1 most important adjustment for secondaries
thank you! He's full of shit on this one. And the side of that bowl got whacked by Tony.
@@Really-AintBuyn-nit "It just broke" sounds like my kid lol!! :)
Wish we could of heard it run
I like how he usually says....phenolic LOL....spot on this time.
I had many low 10 second cars in the day using Thermoquads great carbs BUT they are unforgiving you have to get them set right not much in between room with them. When Carter sold out I contacted them about buying all their jets springs and metering rods they had. Also some tooling for parts for those carbs a deal was made THEN a divorce wiped me out so the deal never happened. I still have about 15 or 20 of them in the garage a few still new in the box never opened in sealed plastic.
I plan on build a 9.90 small block duster using a themoquad using all old school parts remember Direction Connection? if you follow their parts lists for the et you want to run you will hit the numbers.
The Holley rebuild kits have resin impregnated gaskets and the float bowl gaskets have xs material that I would use for the TQ
O-ring seals by using a hole punch kit. So find suitable material and make your own, the carb comes apart with no ripped gaskets if you're lucky/careful! And there is a spring tension setting on the TQ secondary air valve too as well as the primary metering rods.
Greasing the gaskets helps too.
Looks great
One of my all time favorite cars is the dart
Thank for sharing
Thanks to this channel and the power of technology, I have never learned so much while taking a crap.
I've have good luck with those carbs.
I like Thermoquads, specially early 70`s and competition series, I can rebuild them well. On Thermoquads all parts are outside and easy to see and tune by hand and I can tune them very fine for each RPM and each condition, I put it on Buick 455 stage 1 and with them I changed the engine to specs that I want, How to cold start, how to Idle, how to accelerate and jump, etc. Everybody shocking when they find out I use Thermoquads but I guess my mind can understand them or maybe Thermoquads like me.
Lol, love the thermoquad, my 79 scout II hade one, lot's of time tuning every two years for California smog test.
By looking at that Carb it was full of water at some point then froze blowing the body apart, I know they fail but that's what it looks like happened here.
The adjustments on the Thermo quad have to be done in the order that they are listed in the repair manual or the repair instructions. If you look at the vacuum connection on the base of the carb you will notice that there is a built in restriction there. I've not worked on a tremendous lot of these but all the ones I have (about 15) have a restriction at that point. I'm assuming that the factory built the carbs to work correctly on only 1 engine & not meant to be modified. On Q-jets the restriction is in the vacuum diaphram itself. You can use a fish tank air adjustment device to regulate the opening rate of the secondary air valve. That corroded carb you have looks like it was left out in the weather for a few years. I've had some in my shop for over 10 years w/ no corrosion at all. On that little o-ring seal that goes in the bottom, I've assembled carbs & forgot to put those in. Talk about running pig rich. Another mistake i've made is using a Q-jet base gasket on a Thermo-quad. Look almost identical but you will end up w/ a gigantic vacuum leak. I have been buying my kits from Mike's carb & have been having trouble w/ the accel pump material when using gas w/ ethanol. The material will soften & get removed from the plunger. Contacted Mike's & he said that he is having trouble getting them made of a material that will hold up. I'm thinking of putting a shut off valve in my duster so that I can run the carb dry when I park it since it isn't driven much. Just passing on some hard learned info.
Uncle Tony , Most people would say throw that freaking carburetor in the trash , but I do give you credit you stayed with it and you made it happen... as you know it would’ve been easier to put a Carter wfb on there would’ve had the same linkage.. bakalite for a carburetor midsection might’ve seemed like a good idea at the time...
LOL The rot on that carb looks like it got drug down a salt road in the dead of 5 wisconsin winters lol!
I was hoping to see and hear this car running.
You’d be hearing nothing you haven’t heard before mild motor probably sounds like a complete truck motor
HEY UNCLE TONY! I HAVE A T/QUAD TOOL FROM BACK IN THE DAY I WANT TO SEND TO YOU, WERE CAN I SEND IT?
I don't think that corrosion is a problem with the quality, that's been living in water for years.
grumble grumble grumble Just did my 83Riviera fuel pump! Turns out original!
Then my accelerator pump goes! Time fer a Carb rebuild!
Pain, in the ascot^__~
At least we're not alone ^__^ ha ha ha
THNX!
I thought the pull off should hold the door closed not tight but closed. The Quadrajet, we would glue the orifice on the pull off and drill it small amounts till it would slightly bog then re-glue and drill to the size the hit the best. Had to make sure the opening spring was set to specs also. Don't let them talk you out of it.
Aloha Uncle Tony I just picked up one of my best finds today…
10 years in temp controlled garage..
A 1967 4spd Charger with 30k original rust free miles…
The find came with an extra 1958 392 4bl Hemi crate motor and 40 boxes of nice charger parts and 1/2 of the boxes being nice TQ carburetors.
I believe the car currently has a 383 with radiator and carb pulled.
Would love to get a phone consultation. I really wouldn’t mind paying for your time.
Mahalo 🙏
Jim
As much as I like a thermoquad I really hope you get around to using that spreadbore Holley.
Most all of that info on the carb is wrong. Most have no clue when it comes to working on this carb. It needs very little adjustment to work on any car and most tinker with it without knowledge till it wont run right on any engine. There's three version. 800 cfm small block, 850 cfm big block and a 1000 cfm competition series designed for the Hemi but was never used on factory cars. Could be bought over the counter though. The bowls don't crack or bust unless it's got water left in it to freeze from improper storage. The jet wells will come loose with age and cause it to flood, but it's an easy fix with some two part epoxy that is fuel resistant. No big deal. That choke pull off is just that a choke pull off. It has nothing to do with secondary door timing and does not require any restriction at all. It will cause it to not work right if you restrict vacuum to it. That S link is for adjusting the choke pull off only. It will effect the secondary lock out when the engine is cold as well. On our race carbs all of the choke linkage, blades, and pull offs are discarded. So that alone proves this pull off has nothing to do with the secondary adjustments other than the lock put. You can do a minor adjustment by bending the secondary door tabs to make it run richer or leaner. There is a tab on the drivers side that changes how far the door can open and most all need to be upright when running at WOT or you wont get it's full potential. The timing of the secondary door is controlled by spring tension only. It can be adjusted on the drivers side. It has a locking screw that you can use a larger flat screw driver to loosen or tighten it. The smaller flat head screw behind that locking screw adjusts the spring tension on the secondary doors. tighten it to slow the door opening preventing a bog or loosen it for a faster door opening. You want it to be as loose as possible without it bogging at WOT. There is a small screw behind the choke tower you can use to fine tune idle and off idle fuel mixture. Just turn the screw to raise the tree and it will be richer, lower the tree with that screw to lean it out. You can buy or order a rebuild kit from any autozone, advance auto, napa or even summit racing. You can also buy new carbs from Summit Racing and others. I just looked at one on Summit Racing recently for a 74 440 and it was 212 plus a core charge if you don't have one to trade in. Best carb ever made and when set up right, there's no other carb out there that can touch it.
Northumberland Post exactly! I’m a little disappointed with how Uncle Tony responded to all of us who commented about the air valve adjustment. Nobody’s perfect though.
Those Thermoquads can be a pain in the butt, but once you get one set and tuned right - it can be a very forgiving carb. The (2) 850cfm big block versions I put on a tunnel rammed 498cid engine back in the early/mid 90's took a couple weeks to get set right, but once I got needles, jets, and secondary air door tuned right - that thing was a BEAST. AND, didn't get all that bad fuel economy for 650+ some-odd dyno'd horsepower(tuned for street gas, hotter drag strip timing had more power but needed track fuel).
I picked the TQ's because of Tampa FL's hot temps. ...well, that and I got them dirt cheap at a "you pull-it" parts yard. The local speed shop up in Temple Terrance was able to get me rebuild kits and jet/needle kits.
Good series Uncle T. Have enjoyed following your build. Keep 'em coming,I'll keep watching
I'd would like to see uncle tony hang out with Dulcich and freiburger . Imagine the Mopar shenanigans 😁
Jordon Cloutier Frieburger would wear out his welcome after the 1st 5 mins of tinkering . . . the guy is incapable of not spilling huge messes of ATF & coolant, sometimes both in one mess at the same time.
Dulcich uses the old timing method to crack pistons and hammer bearings.So they should get along fine.
Something you may want to look into. I started having issues with my Quadrajet and being I didn't want to spend much, I bought a Street Demon 1900 from the parts store. It was the cheapest carburetor they had at about $320. It's a 625cfm designed around the Thermoquad and AFB by looks, but as a 3 barrel design. It is a fantastic carburetor. Fires right up hot or cold, daily driver application, absolutely perfect all around. I was skeptical at first because of the low price and the chrome shine, but I don't know if I'll ever buy anything different. It's as good on gas as my Quadrajet was and plenty of power.
here is proof that even an expert can be aggravated by a carburetor! I've lost a few battles with carbs and took them to experts to sort out the problem. thanks for the video tony.
The upper flap is adjusted on the other side.
It is spring tension adjustment screw with a lock ring.
There used to be a special tool to unlock while you hold the inside screw.
But you can take a big enough screwdriver to loosen the lock ring while using a smaller screwdriver to adjust the tension.
More tension will cause the upper flap to open slower. It doesn't take much. Don't forget to tighten the outer lock ring.
I can take a TQ from a 440 and place it on a 318 and with a little adjustment, it will run great.
I remember in a video awhile back you showed to bend that s bar to slow down I remembered I’m definitely learning. THANK YOU.
Just want to say thanks again for the videos. Im currently gathering parts for my trans am. At first i was all gung ho to do an ls swap. Now....im putting together a mild 455. Cleaning parts and making it look as good as it runs is way more time consuming i think. Thanks again, cant wait for the next video
Awesome video! There will always be a thermoquad lurking under a hood somewhere Guys like you are getting harder and harder to find!
Please don't give up on the thermoquad! No one gives them any love.
Man you’re tough on these vehicles man. A dying art you’re keeping alive
I know I should play with Holley but I love the thermoquad secondary sound. I have a rebuilt one on my truck and it bogs, now I know why. Thank you Uncle Tony! 😂
The Wwwoooooommmmpp in every gear with the quadrajet and the thermoquad is something else
fucking with the choke pull off won't fix the bog. Go to the other side to find the air door adjustment tool.
The bog is from the air door tension adjustment. That choke pull off is not your problem. It just keeps the secondaries from opening before the choke does and the engine isn’t warmed up.
Hell yes. Bottlerocket at the track!
Knowing that the carb master had to take a carb apart a couple of times to get it right makes me feel a little better about needing two tries to get my old AFB correct. My old man used to hate that Thermoquad, I never really knew what he disliked about it until now.
10-year-old carb rebuild LOL
how could you believe it was still good
Sometimes you just have to admit defeat and get a Holley 👍
C'mon now it's HOLLEY ,....holly is for christmas decorations.
@@396M21 oops I used talk-to-text
@@396M21 what about Chief Cherokee he did the same thing LOL
Thanks Tony - great info, as usual! I've driven two Thermoquads extensively - a new 360 4-speed that worked perfectly with occasional cleaning/minor adjustment and a way used 400 lean burn automatic that worked very well after being rebuilt by a "cash only" place in Trenton, NJ. I'd never heard of a vacuum restrictor to control the secondaries; so, how did the factory get it to work properly? Thanks.
No shit on the vacuum restrictor. Never heard of that either. All the choke pull of does is block the opening of the secondaries when the choke is on.
George Wetzel they don’t use a vacuum restrict or. There secondary air door is spring loaded, and the spring tension is adjustable just like the new street demons. Uncle Tony had a brain fart on this one.
@@Really-AintBuyn-nit And pull the air door closed when you lift your foot off the throttle .
Just picked up a TQ from the wrecking yard. Gonna try it out on the 440 in my 79 Dodge 4x4.
Remarkable thermoquad lesson. Thank you UT
I’ve never had a thermoquad but have had a few holleys in my time,with this car I decided to try the edelbrock and I’m glad I did! The tunability on this as opposed to the holleys I’ve had is by far better AND it doesn’t keep going out of tune!
I had to google that trap door air cleaner. Neat piece.
Looks good toney. Love the car definitely awesome 👍👍
Dude screw commitments...throw a Holley on it and rock and roll. Looking good man!
Why don't you adjust the secondary door using the coil spring on the throttle linkage side?
Uncle Tony likes to "straighten the "S" out of it!" 😂👍
Looking good UT almost their hope you get those bugs figured out it's going to be a awesome daily......👍🤙
got 3 good 850 truck thermoquads 1 1/2 in primaries you kick in the secondaries its just like a passing gear and you can watch the gas gauge drop just as fast but the sound of the 440 big block is like no other
Excellent info on that Thermoquad.
But I'm a big chicken and would stay with the AFB.
The AFB is a great carb too.
TQ FOREVER !!!!!
frozen water in the carbs for years and years dont help either ,lol
wondered why u went with the thermo quad, other choice was a rochchester. Saw ur earlier vid with the spread bore adaptor and thought...Whaaaat?
Interesting to me was an article I read that said Pop Kennedy used thermo quad on his 70 455 GS.
Back then it was considered an upgrade on the quadrajet. Not so much now though.
Holley sold 700 more snipers this morning
Hell, I slapped a Thermoquad on a dead stock 77 Diplomat 318 w/2.71 gears and stock single snorkel air cleaner in the early 90's. Ran with a late 80's Fox body from 55 - 100 MPH.
I’m thinking it needs a mass, wideband, direct injection, variable valve lift and cam phasing standalone management. May as well toss in a pneumatically shifted sequential manual transmission. 😁
Modern technology....
AAAAAAAAAAAAAAAAHHHHHHHHHHHHHHHHHHHHH!!!!!!!!!!!!
NO!
NO!
NOOOOOOOOOOOOOOOOOOOOOOOOOOOO!!!!!!!!!!!!!
Goat sauce from the petting zoo will help. Make sure you wear your full face helmet though
Am I the only one that was looking forward to a video on the initial engine startup?
Tony, adjust the air door screw to 3 1/2 turn, not 2 1/2 turns. Works like a charm to slow down the secondary opening.
You just outlined every single reason to never, ever allow a T-Quad into your garage - E VER!
The fix for that door stop is in the trash!!!! Put a Holley on it.
Loving this series Tony, thanks
Tighten the spring and bend the tab the bog will be gone and it will fatten right up. Those that don't understand a thermoquad send all your money directly to Holley
Everything you just explained about the thermoquad is one of the many reasons im not a mopar guy lol.
Thanks Tony, can't wait to see Bottle Rocket at the track!
Deep 6 that plastic POS....Eddy is plug and play
back in the 80s where I worked, the mechanics would swear at the thermo quad. often they would be draw filing the resin bowl to get it to match and stop leaking when assembled.
Heard that some carter thermoquad barrel carburetors, are hard to tune and keep in shape carburetor.
I store my RQ collection inside and out of the weather, don't have any problem with corrosion. Look like yours were in the rain!
Hey man I just had a quick question for a mopar guy,I have a 76 charger, I'm looking for tubular uca/lca everything I find says 62-74 b body but I can't find nothing for 76 b body, ( I bought some door handles that were advertised for 72-74 but the worked fine, my point is is this a mislabeling since the 75-78 chargers are not desired or is there a change in the b body platform that will make these lca/uca not fit
What happened to the holley that you said you were going to use on this car? Just curious on what change since you made the carb video i this series.
I have had carbs that became junk over the years. The casting warps from Bubbas overtightening screws and you can forget it.
Honestly, I wish you had gone with the Son of the Autolite 4100, the Summit/Holley 600 with the annular boosters.
You would have liked it.
Uncle Tony, please take us to Carburetor Land on our next vacation! Who needs Disneyland anyway...
We have Small World in Carb land: Italy: Webers, England: SU, etc.
Cheers
I like Carter four barrels, I had one back in the day with mechaniacal secondary's on my Chevy. Did haven't have plastic part in it. Is it the same carb?
mrkrzt probably a carter built Quadra jet
Preston Rieger Thank you for reply. Me and Holleys don't get along. Lol
Thermoquad, the iPhone of carburetors.
Jerkwad152 No ! Samsung of the carburetors .......lol.
Jerkwad152 think the champion of that game is the quadrajet
Oh look, I found the inexperienced, snotty, just plain dumb millenial comments that show how ignorant they actually are. There's always at least one... I bet neither of you have ever touched gasoline, let alone a carburator that's as old as your parents. btw, I am using a 6 year old samsung. It works better and gives me less trouble then newer phones.
@@cruzinezy1968
You seem extremely upset. Do you need to lay down, cupcake?
Rockitanski jeez dude you got a bag to breathe into use it
Round track racer buddy had dozens of holleys on the shelve so changing jets or flow rates was a quick carburetor swap.
ROLL UP YOUR WINDOWS!!!... because Uncle Kathy now as Air Conditioning.
Bud, I really hope you read this. By no means you will change your carb, right? Ok. Find the spring and the adjuster on the secondaries. Its like the obes on a rochester. Allen, etc. You dont need a 750cfm carb on it, but you can do it adjusting the tension on those springs. Ive did it once before. But 20mpg? Not even dreaming
Thermoquad; the Microsoft Windows of carburetors.
I feel your pain Tony! It's getting harder by the day to find good Quadra-Jet cores too! At least it's possible to fix their warped air horns though.
I know what you mean, I've always proudly run Q-jets on my trucks and stocked up on several spares over the years, only to find that I had the same problem as Tony. Moisture got to them, rusted the bowls and throttle plates, though not as bat as Uncle Tony's thermoquad there. I recently broke down and started looking into spreadbore Holley's for replacements... :(
thermoquad. sounds like you don't have enough aggravation? why not put an early Hemi underneath it to really get you blood pressure up there? 🤯
Carburetor land! That is where I am comfortable.