The worlds most HATED CARB The Quadrajet - Explained like you’ve never seen! DON’T throw yours away!

[@mattrodgers4878]

The only people who say Q-Jets are junk are either too stupid to understand them, too stubborn to learn, or both.

[@kensnyder2340]

Matt, I agree. they perform great if a person takes the time to learn them. They work off road almost as well as fuel injection. 😄

[@MUUKOW3]

@@kensnyder2340 Yeah they don't flood on steep hills like an AFB or Holley.

[@kensnyder2340]

@@MUUKOW3 ,the single float & bowl stuffer work great. AFB's will work if you use springs under the needle assy. Holley's not so much. Q- Jet usually need the throttle shaft bushings replaced and I usually JB weld the dreaded body well plugs. That black rubber piece they provide just gets fuel soaked over time. There aren't many of these carbs left in tact anymore. I'm glad there are still people who like the Q-Jet. 😁

[@Sunspot-19]

They do not understand carburetion from the word go. Sorry about their luck. When things are in calibration, most carbs are good to go.

[@MUUKOW3]

@Sunspot-19 There are a few out there that are turds like Ford's variable venturi that come to mind .

[@CharlesLaBuhn]

Bought a 1967 GTO from a lot for $400 in 1972 @ 15yo. Learned how to fix it the hard way (no google) and rebuilt the "Q Jet" with the Jiffy Kit instructions and detailed schematic. As a Master Auto Tech since 1984 I can tell you the Quadra Jet Carb is my favorite. Best choke system for cold starts, highly adjustable Fuel/Air mixtures and good acceleration while not dumping fuel like a Holly.

[@gregcampbell3064]

Always liked these carbs. Ran them on a 350, 400, 396, 402, and a 454. All worked flawlessly. First carburetor I ever rebuilt at 18 in the mid 80's on a 402 truck. From that day forward I was hooked on them and have rebuilt several for others and even tuned a few by doing the some of the things Bill describes, just not as in depth. Most thought a Quadrajet wouldn't work so good on a slightly more than stock engine. They were pleasantly surprised. Great video and will definitely watch the next one!

[@keithharris9685]

I reind the beginning of this video to get this guy name. His name is Bill Little of Belmont Automotive.

[@Dark_Knight_USA]

Greetings: U said it. Same here.

[@alfee9411]

💯 agreed Just got one from Vans in Indy for my 72 396 k20. They are far better than others on carbs and electrical.... Had one on my S10 2wd blazer 350/ 700r4 and it got around 21mpg pulling 2 sleds up north

[@Dark_Knight_USA]

@alfee9411 Greetings: 72 K20, I wanted 1 of those 4 my collection. Bummer I had 85 instead.

[@ThisIsToolman]

In another lifetime I had a 1969 SS 427 Impala. It would not go from a standing start. I studied the specs in my Motor book and realized the spring resisting the opening of the vacuum flap was looser for a Corvette. I loosened the tension and suddenly I could set the world on fire from a standing start. 😁

[@DarrylDutton-y3b]

I run a qjet on my jeep. Great off road carb, idles really well at crazy angles. I was on a trail in lake havasu, az and was at a steep off camber angle, engine just purring. A gentleman who I didn't know came up to me after everyone got through the obstacle and commented "Boy, isn't fuel injection great", I of course replied "I wouldn't know", I'm running a Quadrajet! He didn't know what a Quadrajet was. I had to explain I was running a carb, he did not believe me! I opened the hood, he didn't even know what he was looking at. He had just listened to someone in the past about how bad carburetors are!

[@bbivens8263]

Yep, Q-jet`s are great off-road carbs. Much better than a Holley.

[@Sunspot-19]

Part of it is how the float doesn't happen to sink and flow fuel all over the place! Heavy floats are off road's Archille's.

[@kramnull8962]

Well the carb story just stuck around with the points stories...

[@Sunspot-19]

When the Q-Jet is understood and set up properly, they sing. Brass power valves don't go to hell from today's MTBE fuels. The bloke I work with is the carburetor whisperer and has shown some of the methods of dialing a Q-Jet in. Properly done, there will be zero flat spot as the secondaries open and make the passenger soil their Depends... Q-Jets are function over form. Heavy float will cause some issues! There are some sneaky ways of setting up a Q-Jet for a given application. They can be highly reliable with proper setup.

[@RaysLaughsAndLyrics]

Very informative video, thanks for sharing. First Q jet I worked on was on my buddy's GMC Vandura. Was flooding and spewing black smoke with intermittent stalling. Set the float 3 times.. No difference. 4 th time I took the float out I noticed it to be heavy. Purchased a new float. It was considerably lighter in weight. Installed new float.Set to spec. .. Mission accomplished. Smooth idle, no stalling and no rich, black smoke.The original float was a composite material that had it's coating compromised and soaked up gas like a sponge to the point it was internally saturated. Have worked on several through the years and came to have them become my favorite carb.

[@MoparDan]

In my twenties I bought a book on Rochester carburetors and became self taught enough that I did carburetor disassembly and cleaning and overhaul kit parts replacement. In the early 2000’s I did a cleaning and kit parts replacement on an E4MC for my ‘86 Oldsmobile. Come to find out at the time that the air horn casting holes were too small and tight, not allowing the secondary air valve to open. I reamed the two holes with the correct number size drill and assembled the carburetor. What a difference it made even with that Oldsmobile 307 cu in engine when accelerating that Cutlass.

[@alleyoop1234]

I just happen to have the Rochester book by Doug Roe & Bill Fisher sitting on my coffee table! Pretty sure they recommend drilling out the two secondary passageways, but that book is decades old of course. Back when I worked in a carb shop in Prince George BC, most days I would rebuild at least one Q Jet, many days it was 3 or 4 including the re & re and setup.

[@aps454]

There was time in the mid 80s that you could walk into Canadian Tire and order a rebuilt Rochester for a Pontiac Trans Am 455SD and get a beautiful 800cfm race carburetor for $129. Whoever the rebuilder was, was sending out real nice units with well plugs redone and the epoxy never came off, and up number rods and hangers right out of the box.

[@Mark-um7ey]

Nothing beats a well tuned qjet on a stock or mild build. Qjet works great with AC cars with the fast idle solenoid in HP builds. Only problem with them is people don't know how to tune them.

[@808ecobeast7]

Yup, my cousin was a Quadrajet tuning guru .... when done right, the Qjet is a great performer and street reliable!!!

[@Geezer1320]

That was the best and most informative video I’ve ever seen on Quadrajet carbs. Learned a lot. Back in the day I ran one on a Nova and it ran great. Best thing was if you kept you foot out of it you got better gas mileage than a two barrel because the primaries were smaller. The accelerator pumps would wear out kinda fast, but it was an easy fix. Yep always liked them. Worked good.

[@thebluelunarmonkey]

My cousin rest his soul had a '66 Chevy II Super Sport nova with a 327. He had the art down of keeping the carb tip top. He never bad mouthed the q-jet. He actually called it a quadra-jump.

[@shadvan9494]

I love the Q-Jet. some of the hottest cars from the 70s had Q-jets. 455 Buick GSX phase III, which is considered to be the fastest mid-sized muscle car from the 60s and 70s, had a Q-Jet. the Pontiac GTO and Firebirds all had Q-jets. Olds 442 400s and 455 all had a Q-Jets. I have two books on Q-jets. one is from Doug Row and the other is Cliff Ruggles. both are invaluable when tuning Q-jet. Q-jets don't leak around the fuel bowls like a Holley once you get them setup, they just work. the only thing you need to do to a Q-jet is change the fuel filter. I change mine every other time i change the oil. power valves don't blowout. also, there is nothing like the sound of a Q-jet at wide open throttle.

[@antilaw9911]

I'm always impressed when good power can be made with factory parts. Anybody can buy aftermarket bolt on stuff.

[@UncleVom]

Another great episode of Gold's Garage! The Quadrajet dates to the mid-sixties, it is as if they knew the game was going to change a decade down the road and they created a flexible design to adjust fuel delivery profiles. The design was solid from the start and it needed less to keep it current, it made it to the end of the 1980's for GM. It is amazing how they juggled and smoothed the transitions to the stages. It is almost like a CV carb in a rather heavy disguise. It has been a long time since I used a Quadrajet, last time was in my 1986 C10 shortbox, good fun and yes I admit it, I was a throttle plate driller. It did idle, smoke the tires and would also pull a trailer, life was good. (-;

[@gordonborsboom7460]

The last Q-jet was on the last Olds 307 engines. 1990 according to the internet. SBC already had TBI, I guess.

[@joshuagarvey9362]

All of us old guys have had one back in the days.When those secondaries opened up you could definitely hear it 😂.Very good reliable carburetor.Buddy of mine still to this day will not give up on his Quadrajets.All theses old school mechanical tech really does the job.I still run these poor man Muncie transmissions and they hold together under this 550 hp sbc.Stuff was so simple back then.

[@mrho4speed]

Great video and I loved the cut-away view. Thank you for making this video and educating so many that the Quadrajet can be a great carb when set up properly = for fuel economy and performance.

[@red-doggracing5557]

I had a 1970 Chevy truck I bought a 365 horse 327 Corvette engine at a Auction rebuilt it all the way back to stock my Holley carburetor was junk I put a 800cfm Quadra jet off a 1969 ram air 4 400 Pontiac engine man what a difference Carburer stayed that truck ran 13:58 115 mph 3000 stall 4.11 gears Positrac

[@badgasser]

i recently switch from tbi on my 88 3500 454 silverado to edelbrock intake and a q-jet, i rebuilt my first q-jet carb that had been on my shelf for years, on my maiden voyage i traveled 675 miles with no hiccups, i have many other q-jets left to rebuild will be viewing this vid many more times as a guide. thanks for posting this educational program

[@my1971nova]

I remember rebuilding the Q jets in the 80s. I have forgotten all that stuff so this video is great and reminds me of some of that stuff. I'm glad I still have one Qjet left, just have to find it somewhere to use on a BBC

[@stevesadusky8634]

I always had great responses from quadrajet carbs

[@Dark_Knight_USA]

Greetings: I know a few people across the country that know Rochesters well. Others claim they know yet cannot prove it. Historical experiences have proven my knowledge, skill and proficiency. Me, not being authority, however I recognize knowledge and skill. I add this man 2 my list of yhe rare, few and knowledgeable. Good job sir. My compliments. Bsafe. Thx 4 the share.

[@Dark_Knight_USA]

Greetings: Great presentation. It is nice 2 know there R still some of us good Rochester guys around. U have my salute and respect. Keep up the good work. Bsafe.

[@546cowboy6]

When he says Holly is uncomplicated who is he kidding. I have never had one but many Quader jets and they are by far the easiest to work on. One thing to remember is the Carburetor the Quadre jet replaced was an absolute nightmare with linkage going everywhere all needing adjustment to work properly. I had an owner once who called me Mr. Carburetor because I did so many. The truth be known I did hundreds that didn't really need it when all was said and done but it satisfied the customer and paid me well. I can tell you I never had one I had to modify with those rods into the secondary jets or anything else. the biggest problem was the plugs in the bottom leaking gas into the manifold fixed with two part sealer so they couldn't leak.

[@CK-mf6du]

Thank you for sharing this! I was in need of those numbers for the idle circuit! I'm always amazed with the performance of these carbs.

[@rickgolden1419]

Personally,I LOVE the Q-Jet! Once you ounderstand HOW it works,and the little quirks,and how to overcome the LITTLE things,it's not only efficient and responsive,but EXCITING when it works!

[@troymecey]

Great carbs. My 86 GMC came with one on its 4.3v6. Im now running a crate 350 with a factory 395 roller cam and the Qjet still performs flawlessly.

[@ajalwin2485]

I’ve been driving Quadra jets for over 50 years. I’ve never had one I couldn’t tune. Love ‘em.

[@michaelmaher4328]

Excellent info, I epoxyed the fuel wells that would leak and learned how to adjust the secondary baseplate screw, i made a small screwdriver to use upside down. I had a holley 6210 that the transfer tube would leak and preffered the q-jet to the holley.

[@craighansen7594]

If you call Quadrajet carbs junk, you dont understand carburetors in general. The shortcomings are pretty minimal.

[@TheBlackPaulMuadDib]

Wow alot of knowledge, love it all. Thank you keeping the old school ways alive.

[@toddbrown2236]

Wow! This is a fantastic clinic on Quadrajet carbs. Well done. My '76 Vette (L-82 motor) had a Quadrajet carb and the car performed well. The engine only made 210 hp but I never had any issue with the carb not functioning well.

[@ocam988able]

Great information. Worked on many quadrajets and they work great once they are tuned right.

[@JimmyMakingitwork]

Taking your quadrate off back in the day was something you did because your friends did. Like lowering your car today. Makes it worse for daily driving but you think you're cool. What many people don't realize is that within limited power needs the quadrajet is a great option. If it can flow enough air for your needs, it is a better more reliable option, imo.

[@jessemartin4544]

I am 70 years old working on cars for 54 years professionally I have been telling people the q-jet is better than a holly all these years

[@joe-hp4nk]

People like Bill are the last of an elite breed of old school hot rodding.

[@sharkbit76]

The Quadrajet is a very good carburetor, but does have some weaknesses. The early versions had the secondary fuel outlets below the secondary air blade. If you fill those holes and drill them above the blade there’s a smoother transition when the secondaries open up. Signal is stronger so more fuel comes in quicker. Total power stays the same but the engine responds better. The later carbs came from the factory like the so if you have a couple the one to build is the newer one. Another advantage, the newer computer controlled carbs have a little more volume in the float bowl once the solenoid is removed. Even so, the float bowl is small so a high volume fuel system. Twenty five years ago there was a 70 Buick GS 455 that ran tens with a Quadrajet and a 3psi fuel system. I’d still rather run a Holley on a drag car but if you are limited by class rules you could do a lot worse than a Quadrajet. For the street the Quadrajet is more flexible and can be easier to tune for good partial throttle conditions, and will probably use a little less gas than a Holley. The trick is getting the right metering rods. The later carbs had big fat metering rods that made them run lean. I had an 84 TransAm that I dropped a 350 in with a Crane cam. I tried a Qjet off my 454 Qjet that was massaged and it felt like another twenty cubic inches. And still got over 20 mpg on the highway.

[@dirtlump]

Very imformative, Thx for sharing. On some later Quadrajet Models.... there is also an adjustment on the primary metering rods start height(the amount the Taper on the Rods sits down in the Jets) by adjusting the height of the "stop" that the vacuum plunger sits down on(That little tang sticking out of the Vacuum plunger on some models that sits DOWN on the stop that can be screwed UP or DOWN)) This adjustment can be done during a test drive after carb rebuild, by removal of the Tapered "Plug" in the top of the Carb directly above the Primary Metering Rod Vacuum Plunger well during rebuild and left out for the test drive(it must be punched UP from bottom).... then a special screw driver can be used to adjust the "stop" up or down for more/less exposure of the Jet by moving the Primary metering rods start point. When happy with the opening simply push to Tapered Plug back into the top of the Carb.

[@bbivens8263]

Really liked what Bill said about the Mercruiser Q-jet secondary door, open it up for 20 more horsepower and charge you extra for that!

[@dondotterer24]

Awesome AG. You know I would be excited to see this. Bill did a perfect job. The best video on a Quadrajet! Looking forward for more.

[@nebraskamalt6949]

They were called Quadrajunk and quadraslobber, but I always liked them. When they wear and begin to leak, motor sport specialties in Hutchinson Ks, line bores them.

[@Inthefoxhole]

I ran a q jet on my 1973 Short wheel base chevy van.Never had 1 problem with it.373 Rear gears,350 turbo trans wirh a 11 B&M stall converter.It ran better and faster than a holley double pumper.1 tiny piece of trash will make that holley flood and cause a fire.O jet no issues at all. Choke works better also

[@jeffgriffith7003]

I still use a Quadrajet on my 77’ K10. It works well in the cold, but sometimes the choke doesn’t sit where it should or sometimes it doesn’t release off the fast idle cam. I need to give it a good cleaning and add some powdered graphite to all the linkages and moving parts to get at 100% again. I make sure to run non-ethanol fuel to minimize the fuel evaporation out of the bowl and it usually starts pretty quickly as long as it hasn’t sat for over a week.

[@glennk1931]

Worked on Quadrajet carburetors back in the 1970’s. They had a couple of issues, but have always thought they were excellent carburetors.

[@hardball107]

Never say never, I have been building Q Jets since the 80's when I was running a D Stock big block Camaro. The weak points are well known and can be easily corrected. I often look for the models with the aluminum plug over the primary metering rods. I knock that plug out for access to adjust the primary metering rods and NPT shallow tap the cover and install a flat pipe plug to seal it. I used to have my carbs blueprinted by a place called "The Carburetor Shop" in California for my race cars. They sold all kinds of Q Jet parts and kits, wish they were still in business. I've never had a Holley ever run as good as a Q Jet. Even today I have a chopped, mini tubbed '68 C10 I swapped a cammed LM7 5.3 LS with long tubes into that I use for a daily driver. It has a single plane manifold with a 800 cfm Q Jet on top and she makes a great grocery getter but when you put the long pedal down and that air door opens up she can really scoot. Love that sound when that happens especially at 6800rpm.

[@keithlarge1151]

Being a former IHRA/NHRA stock eliminator racer these were the only carb we could run on our choices unless the engine had a Holley from the factory. The other carb was the Carter four barrel on the early to mid 60's Chevy small blocks and both carbs made great racing carbs with many world records seg with them even today

[@dennisgumm7016]

I grew up in the seventies in Decatur, Indiana listening to John Lingenfelter firing up and loading his race cars on Thursday or Friday nights to get them trailered up. He was such a Quadajet guru that Chevrolet and General Motors fed him ALL the new products they had in development as related to Quadrajets. Just dropping a set of his old metering rods in a stocker carb would show noticable performance improvements. RIP John.

[@MrMarkar1959]

I still have the rebuild manual's for Qjet's etc..,i. rebuild several and replaced it with Holley 650 Spreadbore which i had no problem swapping jets and rebuilding back then.

[@overdrive39]

Thia was some great information! I learned a few thing today on these carbs. I have been messing with my 800 cfm Qjet for my 502 big block and I cant wait to get out there and try some mods. THANK YOU FOR THE VID!

[@larryalexander4833]

Good Sunday morning 🌞 I appreciate the video and the information. Thanks for passing on the what you have learned. 🙏💪✝️

[@4speed3pedals]

Thanks, this was very interesting. Reading a book on things to do to a carb doesn't match up with what Bill explained. I an anxious to see him work a Q-Jet into a race carb.

[@nesadx11]

All my cars pre FE had Quadra jets on them, they worked like a swiss watch.

[@user-tn1hk6zm2freedom]

It runs on 4 barrels all the time. I have 3 of these carbs and you have me thinking. Very good video. Thank you for this video. I have a 71 Torino Cobra with a 429 SCJ engine and I also have a 429 CJ intake and carb. I may give the Q jet a try?

[@GrandPitoVic]

Not a great looking carb, but I love the sound when the secondary opens lol!!! Like most people, I couldn't rebuild it worth a flip lol!!

[@v1-vr-rotatev2-vy_vx31]

Love tuning the Q Jets,,800 cfm, and they were on the Fords for one year...

[@anthonytumbarello9940]

I love Q Jets. I put one on a 318 Chrysler got great gas mileage and great power. Chrysler used them from 1985 t0 1989.

[@rickybearden4575]

i always liked a quadrajet carbureteur on the older cars flip the breather top upside down it would moan i read that the the rods that goes through the side of the carb that has the rubber seals would wear out sucking air would make you think you had a vacuum leak !!! good informational video you could put bigger jets for more power good job men !

[@RodneyHayes-d3y]

In the late eighties I was running a quad on oval tracks and the adjustability that is built into the quad carburetor was amazing if you would learn how they work. Only problem we ever had to overcome was a lean condition on the top end of the long track we ran. 5/8 mile. Simply went to a high-pressure pump regulated for low end and a 1/4 ball valve working of the throttle at wide open to bypass the regulator. We found you could watch the plugs and tweak the secondary metering rods up and down and move the fuel mixture around to get the best color on all the plugs

[@paddle_shift]

Back in the early 80s i got my parents 74 Cutless S with the 350 Olds engine. I immediately took it to my engine builder friend and we built up a clone W31 engine to mimic the W31 Cutless 442 from 1970. The only thing i changed from the W31 was i used a Holley 700. The car drove OK, but never quite like it should. I switched to a spread bore Holley that was also not all that great. I tried a 750 double pumper, not great. My engine builder who was a very old but wise man said i should have stuck with the Quadrajet. I thought he lost his mind. But i went to a local salvage yard and found a Quadrajet from a 442 that had a 455 in it (the engine was blown up at the block). I put that on my car and the difference was unreal. Drivability was great and i could melt my rear tires if i needed to.

[@454ho]

Great video, always wanted to know what the stock & super stock Q-jet mods. I sure Bill has a few more tricks up his sleeve. Love to see a video with Bill on those 461 super stock head.

[@Ace-jd2yn]

I love my 800 CFM Rochester on my 406 SBC 20 MPG

[@MUUKOW3]

I was always a Quadrajet fan. Never got along with the Holley and those power valves . I like the yhe Cafillac quad thas has the adjustable mid throttle screw.

[@MUUKOW3]

I forgot the one thing with Quadrajets is that they were individually set for each engine they came on so just swapping them around didn't always work out so well . Look for the ones with the external metering adjust. Gives you that extra bit of tuning.

[@gordonborsboom7460]

You mean the adjustment the service manual says to never adjust!

[@MUUKOW3]

@gordonborsboom7460 Well of course , the super secret one the EPA hides lol.

[@royosborn7869]

Thanks for the education Bill - nice explanation. Thanks for taking the time to publish this.

[@jb-ik8sj]

I've never owned a holly. Q-jet has been my go to carb since the 80's

[@davepilling3134]

Mercrusier went to weber carbs when the quadrajets weren't available any longer. I'm curious what Bill's opinion of those are. Should I switch to holleys or can the webers be modified to work better after engine mods. Thanks Allen for another interesting video

[@mewrongwayKOCXF]

DAMN good carb if ya know how to work it! 70 Chevell, 69 large journal 327, Put so many Mustangs in there place that it wasn't funny! And that sound of a jet taking off so kool!

[@roberthanks4626]

Only problem i had with quadrajets was accelerator pumps

[@chrisromero5302]

I had Qjets on all my old Chevy and GMC trucks. I had one on a 350 and 400.

[@ibraunchy20-vn5kd]

Was poor as a kid so I got all my buddies old hand me downs like their GM Q jets , I rebuilt many of them on the dining room table , love em , could ease around on front 2 barrels but when needed the back hog legs would get with the program , I've ran em on everything from a 283 to a 454 ,some of the factory big block Q jets were 850 cfm

[@OneManGarage]

Secondary opening rate is actually controlled by the vacuum pull off more than the spring tension adjustment is secondary to it. Early first Gen Quad had a slow 2.5 second opening rate and the rod connected to those flaps means regardless of how much engine pull or rpm is under it , it still takes ,2.5 seconds to allow it to fully open then in 70s they started changing the vacuum pull off to 1.0 seconds start to finish of letting the flap wide open and what ya really want. Eliminated bog of a broken one but opens quick enough to be just as quick on the track as any Holley and as discussed will support 9 second 1/4 n/a drag cars. I have gone 6 sec 1/8 with mine

[@terrypikaart4394]

Q Jet is best carb ever made for street car. Its only hated because it design is over some owners heads. They don't understand them.

[@steelcitycaprice.899]

I grew up in the quadra jet era and I use to laugh at my uncle's smacking one with a screwdriver and listen to the idle smooth out 😂😂👍🏼😎

[@GrandPitoVic]

As much as people hated them, there is nothing that sounded like a spread bore carb!!!!!

[@thereluctantgearhead4544]

I once built myself a gas miser, had a 120 mile round trip to work everyday. I used a 1984 190hp L-69 305 from a Z-28. Did a basically stock rebuild on it, .030 flatops, cleaned up 416 iron heads with Manley replacement valves. 1.84/1.50. Nice valvejob and .012 milled off. Used the old GM "Z-28" springs, Comp roller rockers, a Comp 260 HE flat tappet cam, Edelbrock Q-jet pattern performer intake, old 1970s 4165 Holley 650cfm vacuum secondary carb, HEI distributor and 1 5/8 primary, 3 in collector Hooker headers. Backed up with a basicly stock rebuilt 200R4 trans and a 3-42 gear & Eaton posi. It was in a 1985 Pontiac Gran Prix. That car got 30+mpg on the highway and 25+mpg in town. And it would do 300ft smokey burnouts on 275/60/15 street tires. Looked good, sounded good, and it got extremely good MPG. And as a bonus it ran pretty good too. It was a low 14 second 1/4 mile car. Real good work car if ya gotta go far. Later on it ended up with a 600+hp 385ci sbc, T400/5000 stall, & a 12-bolt swap with a 4-88 gear. It evolved over the years. But the first build on it was all about how many mpg I could get out of it. It ended up as a drag car that got trailered to the track. But I was always impressed with how well that Q-jet replacement Holley 650 vac sec 4165 carb worked. Real good street carb in my experience with one. I like the Q-jets too. Built plenty of those as well. Good carb for many applications.

[@Dr_Reason]

You can get a really bad bog if the secondary metering cam breaks.

[@greggc8088]

I like the durability of the Quadrajet but the Holley dual accelerator pump 4 barrel with it's mechanical secondaries was always easy to tune so that was my race carburetor in the years before their metering blocks started warping all the time. Then, and to this day, I chose the Edelbrock AFB design carburetor.

[@alleyoop1234]

I have an old friend that used to drag race a 67 Beaumont with a 327, he was always known as Carter Ken. His car ran 10.70s at Ashcroft!

[@tonysendrick6347]

The AFB is a Carter carb.. and there was the WCFB by Carter... Edelbrock brought the AFB back from the dead..

[@greggc8088]

@@tonysendrick6347 Yes

[@scottnovak8903]

I had a 1977 grand prix had a quadjet but had a adapter plate blocked back ports and I had ridiculous gas mileage, at stop slow acceleration but had high end could be 150 mph, never investigated and love to know if it's real I experienced. 2 barrel and quaderjet my favorite, seeing your halfmoon on front plates made totally sense since I always had dead spots. Thank you guys.

[@SOLDOZER]

Nothing beats a well tuned Q Jet.

[@RichardGifford-i1m]

The hell with holleys unless you like fiddling with your carb. You can keep them. The Quad is a way better setup. Easily understood if you can read.

[@1TOPSPEEDPERFORMANCE]

The sealer on the plastic float would crack with age and the foam in the float would fill up with fuel and the float would sink slowly and make them run rich, till they flood.new float every 10 years and and learn how to do a simple set up and they were great. Very adjustable and street able with 3 sizes to do up to 450Hp.I ran a dyno a watched many swap to a Holley and lose power and driveablity

[@95Sn95]

I'm no quadrajet expert like bill but In my experience the quaddra bog comes from the air valve adjustment being incorrect, every one that had bad bog that valve is floppy loose, and yes if you can get more fuel to the secondaries quicker then the air valve can open easier this faster but if the engine can't pull enough vacuum they shouldn't open very fast anyway. Wonder if anyone has put pumpers on the secondarys. My quadrajet hated my combo, that was a Torker with a 2" spacer/adapter a 108lsa 231° .480" lift duration cam and ported iron GM heads. It pulled like hard up top but it needed enough throttle adjustment at idle it bypassed the idle circuit and idled super rich. You could turn the screws all the way in and it didn't affect the idle. Mine was a "recalibrated" one from summit racing had an 800cfm casting.

[@derrelcarter9401]

Thank You, it is great to see this carb explained in depth.

[@martincaballero355]

Quadra bog!!! First carb i ever rebuilt. Dad tought me in the mid 80s. He would tune by ear.

[@Rick-S-6063]

I've never heard the Quadrajet referred to as the Quadrabog, but the Carter Thermoquad has been called the Thermobog many times.

[@yafois988]

1st one I built, 7029263, for my 69 RAIII Bird. Ran almost as good as my EFI accord, idle to WOT! thx to Cliff .

[@thisisyourcaptainspeaking2259]

Qjet is my favorite, t-quad is my 2nd favorite.

[@kd5yut]

my 500hp 396 doesn't like holley. With the right jetting and metering rod tension on my q-jet she'll honk!

[@gothjim325]

Man, I loved the old Quadrajets. Had a 350 Chevy that was a monster. I had a Pontiac 455 with the 850cfm. There is just no fun like putting your carb on the kitchen table and working all day on it. I hate this new stuff. It's made to deter you from maintaining it.

[@randalcomercomer3011]

You guys need microphones can hardly hear your valuable information please love your work

[@1TOPSPEEDPERFORMANCE]

Q Jets are great,olny problem I found was the floats where foam plastic with a seaaler o

[@justs-28445]

Brass floats are AVAILABLE!!

[@100amps]

Well, that was fascinating, but I need a 101 course before this makes enough sense. I'll come back and watch it again after a more introductory carburetor lesson.

[@billlittle4285]

Some more is coming soon

[@bbivens8263]

Q-jet`s and T-Quad`s for me. Gave away the last Holley I had. Got a brand new Edelbrock AVS-2, would not run off idle, went to remove the top, 3 screws stripped out on the aluminum top. Edelbrock had used screws that were squeezed on three sides like a mechanical lock nut. A stupid idea in an aluminum body. So I had to heli-coil all of the holes, and run a die over the screws to remove the high spots. One of the metering rods was bent at the tip from the factory, that`s why it would not run off idle. I was so disgusted, I put it back in the box and re-installed my T-Quad. Edelbrock tech and warranty is non-existent, nobody answers the phone.

[@kimmorrison9169]

I’m sure there are some fast stock eliminator and super stockers using that Q jet.

[@genesmith4019]

A tapered needle is used in European SU and Stromberg carbs. It is simple and effective. The European carbs don’t even need accelerator pumps. I like my Quads on the sbc engines on my boat. I wouldn’t trade them.

[@Al-Fiallos]

Best carburetors I ever had. Smooth power from idle to full throttle and excellent miles per gallon. My experience with Quadrajets was back in the 1970's both as a mechanic and user.

[@kh40yr]

The best carbs I have ran and own is Pro Systems custom carbs. Built to specific engine, transmission, rear gear, vehicle weight, camshaft, fuel, engine cubic inch, ect. Pro System Racing Carbs. They wet flow and truly care about the carb you need. They have done about 3 street carbs for me without fail. Bolt on and start the car, is just about that easy.

[@jeffwombold9167]

Brings back memories. I got hired years ago because I was pretty good with the Qjet. (We had a 389 that ran low 9s on a Qjet).

[@erikalarson6803]

I've watched this three times so far to take notes. I've read Cliff's book and Bill does a great job explaining the concepts.

[@markmcmullen1371]

Good show AG, thanks Bill. 👍👍👍

[@dean-zb9nt]

thank you for your time.

[@gabriellindig]

I have a 820 cfm Holley spreadbore double pumper that I've been off and on rebuilding because I was going to run a q-jet manifold on my big block, but I decided on efi, so just it's sitting in a box in my garage