You know when you have a real mechanic when he tunes the Q-jet by ear and it runs perfectly, RIP Jim Clark.

@20alphabet

2 жыл бұрын

Lol, nothing beats a vacuum guage and a scope.

@rastacj2769

2 жыл бұрын

You got that right. My brother has been doing it that way for the last 30 years. He's a wizard with tuning an engine.

@jhershy1381

Жыл бұрын

Cooool. I had one on my 1977 riviera 455 boat tail. Makes me think i may go get one for my 1985 mustang.

@jku72

8 ай бұрын

I’m not a real mechanic- so prefer a simple carburetor that fake mechanics ca. easily dial in. I certainly agree it takes a special expertise to make a quadrajet work properly. I just don’t have it.

@lilibethdoherty295

8 ай бұрын

You Missed the best EFI from Ford in 1986. In 37 years my 5.0 has only needed a throttle position sensor, otherwise it has performed perfectly. @@jhershy1381

The quadrajet is one of the best OEM carbs ever made! You can adjust the quadrajet's secondary air valve plates to either open sooner or later. There's an allen lock bolt on the under side of the top hat, and a set screw on the side. The set screw on the side (passenger side of the secondary part, controls the secondary air valve door tension spring. Counter clockwise lessens the spring pressure (open sooner), and clockwise to tighten the spring tension (open later). Here's an OK video on how to do it. Skip to 8:35 in the video - kzread.info/dash/bejne/g5yCu6-fpNq0hdI.html

@OldeCarrGuy

4 жыл бұрын

I’ll be sure to check that out! I want this thing working mint!

@davelowets

2 жыл бұрын

That's just one of many tuning abilities of the Quadrajet.... Great info though. 👌 If you REALLY want to get into tuning and modding the Q-jet, check out the book written by Cliff Ruggles on the subject. It's a wealth of great info, and a great read. I've been in the 10s in the quarter with a Quadrajet after learning how to work on them.

@Harrybowles1969

2 жыл бұрын

Yea run secondary flaps as loose as you can before bogging for performance or stiffen up for fuel economy so they only open up at higher rpms!

@chickenjo23

2 жыл бұрын

Most people adjust the secondary too loose. Those secondary blades when you press on them need to snap back pretty quick.

@Harrybowles1969

2 жыл бұрын

@@chickenjo23 agreed. loose secondary flaps can cause the famous quadrabog which baffles so many people 👍

For a street car, I LOVE a Quadrajet. It's the people who don't understand how they work, and don't know how to tune them, that call them "junk". They were a very well designed carb, with some clever circuits inside them, that made them work very well of you knew how to work on them. There's MUCH more than just turning on the air/fuel mixture screws and hoping for the best. For racing, the Quadrajet has a few shortcomings, and a Holley style carb is superior. For the street, a Quadrajet can't be beat.

@OldeCarrGuy

2 жыл бұрын

The Q-jet has far less shortcomings than the 1406 Edlebrock for a daily.

@jku72

11 ай бұрын

I have found the 1406 to never have to need maintenance, year after year. The several q-jets, when working, are better performing, but I just got tired of the maintenance to keep them that way. I chose to sacrifice the slightly better mileage and responsiveness in favor of a trouble free carb that never needs anything. Was a q-jet man, just got sick of fiddling. The edelbrock just works, and there’s something to be said for that.

It might be considered "cheating" but a wideband O2 sensor and gauge is very helpful for tuning a QJet. You can know exactly what's going on in the primaries and watch the mixture during and after the secondaries open.

Something people don't mention about the Q-Jet is they work WAAAAAY better offroad on steep angles. The 1406 don't like angles at all. Yes i've ran both and both have there perks. I'm more offroad so I lean towards the Q-Jet

@OldeCarrGuy

2 жыл бұрын

Great point Aaron! Thanks for watching.

@lilibethdoherty295

Жыл бұрын

Another reason I love VA. Beach Flat and Edgar Cayce said safe too !

The Rochester Q-Jet is a great carburetor, Has infinite adjustments! They just dont have any fuel bowl capacity.

@OldeCarrGuy

3 жыл бұрын

Thanks for your insight and for watching.

@briansd2772

3 жыл бұрын

Assuming you have the rest of the carb dialed-in, shave 1/4 inch off the black float bowl insert and use the later, 1975+ in most cases, smaller sized float(NAPA/Echlin 2-442) to free up space for more fuel. Install a RobbMc high volume mechanical fuel pump and a .135 needle & seat assembly with float levels of 1/4 to 5/16 inch, and enjoy trouble free quarter mile blasts.

@davelowets

2 жыл бұрын

@@briansd2772 Exactly! Great info. Many people dont realize the greatness these carbs hold. I've been in the high 10s in the quarter with my modded Q-jet. I wouldn't try to go much faster than that though with one. I'm in the low 9s now, and a 1050 Dominator is what I use. The Q-Jet would have never been able to provide enough fuel to go this fast. They are however GREAT street carbs, and good for mild drag cars also. For a daily driver, I'd use a Q-jet over a Holley any day.

@chrisrogers8927

2 жыл бұрын

Have a Quadrajet on my 84 Monte Carlo SS and it’s been terrible, it floods the engine with gas and fowls out the spark plugs no matter how you adjust. No one wants to touch it at this point. Having it switched to a Edelbrock with Electronic Fuel Pump!

@72chevelle156

Жыл бұрын

it's not the primary fuel bowl. there are 2 holes on the side rear that feed the secondary bowls where the 4 tubes from the horn fit into just make them bigger until you don't lean out on the top end. check the vid on my channel.

I had a built quad on a pretty hot 355 with a stock cast manifold , being a 17 year old at the time I didn't realize the carb was worked, I thought I could improve that setup with an performer intake and a 600 edelbrock , bid mistake ! It didn't pull out of the hole like the quad , boy that quadrajet sounded sweet when the secondaries opened

@OldeCarrGuy

3 жыл бұрын

They sure did...Especially when you flipped the air breather lid! Thanks for watching Matt.

@theeoddments960

2 жыл бұрын

The primaries being so tiny are a big plus in that the velocity of the small holes help in bogging when you first hit the gas. Bogs pretty bad in the transition from primary to secondary though.

@zragevii4705

2 жыл бұрын

@@theeoddments960 bog is tuned out for the most part with spring on the air valve.

@tonymayhew191

Жыл бұрын

Most guys don't know this, But the stock intake manifold has a better flow rate than most aftermarket intake manifolds!

The Q-jet is the best carb, it has all the adjustments for economy and performance driving. In some models it has altitude compensation.

@OldeCarrGuy

2 жыл бұрын

Thanks Sir

@Schlipperschlopper

Жыл бұрын

SU carbs arent bad either!

Not having a choke creates a lot of problems with Qjets. There is a vacuum port inside the choke housing. You have to plug it or you will have a vacuum leak. I know this from experience of putting an electric choke on my Qjet. I did a smoke test to find vac leak, plugged the port and it made a big improvement. Also for the Qjet haters, these carbs have a number stamped on them that specifics the make, model, transmission, engine, etc. They were designed for specific engines. Therefore, if you use a Qjet on the different engine you have to change the needle and seat, the jets, the secondary rods, idle circuit and even the cam that lifts/engages the secondary rods. There are spec sheets that show what application the carb was designed for. Whereas, Holley’s, Edelbrock, etc are for a wide range of applications.

I've always refered to it as the quadratoilet. That said, I like them and have owned them on all kinds of engines, from 305 sbc's-440 big block Chrysler engines. I love that Q-jet s sound when the secondaries open up too!

@OldeCarrGuy

2 жыл бұрын

Don't forget flipping the lid on the air cleaner! lol

The quadrajet and the thermoquad were excellent carburetors however they were finicky and were rarely tuned properly, especially how the secondaries were set to kick in. Often it was too soon creating that bog everyone hated. I rebuilt some way back in the day and also tuned several, including running one on my 68 Charger R/T in the early 80’s. A thermoquad on a 440 Dodge….. When those vacuum secondaries kicked in I swore you could see the hood buckle. I’m so much of a fan I have one to go on the 440 I’m building form my 68 Coronet R/T. Thankfully I can tune it so it won’t be an issue for me at least. Plus if you own an old classic with old classic parts, you’re guaranteed to have to tinker. Great video.

most Qjets are 750 cfm unless its from bigblock or ramair pontiac got 800 cfm the main reason Qjets get bad reputation is from the ppl dont know how to tune them properly ive seen 1000hp pontiac's with just a tuned Qjet

@OldeCarrGuy

4 жыл бұрын

Yes. Mine is a 750.

@billiot425olds

3 жыл бұрын

The Cadillac 500 had the 800 cm as well.

@sierraridgereaper

2 жыл бұрын

Most of the big cars (CI) 76 and later used the 800.

Looks like the qudrajet has way more responsiveness

@OldeCarrGuy

4 жыл бұрын

Oh yes

@zragevii4705

2 жыл бұрын

Acts like a tiny carb until vaccuum pulls the secondary air valves open. meaning if you tune that transition correctly it will be a wild start off the line.

I had a 75 cutlass that quad. Sounded like it was sucking the dam hood through it. Fastest stock car I ever owned.

@OldeCarrGuy

3 жыл бұрын

No doubt!

Glad to see that you put a Quadrajet on it I found quadrajets to be very responsive to be the bottom end due to the fact that they have dual boosters in the primaries so you get a very strong vacuum signal I have installed one of these on my small block Chevy with a oftenhauser dual Port intake and I don't even need to use the accelerator pump because the vacuum signal is so strong from the small primary ports

@pjimmbojimmbo1990

5 ай бұрын

The Offy Dual Port was an Interesting Intake. My friend had one on his CSB.

@imaouima

25 күн бұрын

DPs are as misunderstood as Q-Jets. Always liked them.

Yo Jason, 8:56 You're using the wrong app on your phone to record your 0-60 time. You need to open up the Calendar . -Chuck

@OldeCarrGuy

4 жыл бұрын

Oh Chuck! How I’ve missed thee!

@buttcrackcycles

4 жыл бұрын

Now that's funny

@AntonioClaudioMichael

4 жыл бұрын

Lmfao

@bee4472

2 жыл бұрын

Hahhahahaha !!!!!

My 1980 trans am turbo with a 301 has an 800 cfm quadrajet, and that is factory. How they make it work on such a tiny engine I don’t completely understand, but they have on the intake manifold a power enrichment valve regulator or something like it,that opens the secondary jets I believe. Great video.

My 77 Vette might not be that fast, but the sound it makes when the quadrajunk opens up is worth the sacrifice

So Scientific. Great video as always. You are killing it.

@OldeCarrGuy

4 жыл бұрын

Thanks my man! 👊

Great VS video. Dont forget your throttle cable adjustment has a big effect on your 0-60 because it effects your shift points and max RPM's before the shift. If you check the shift points before swapping carbs or check your line pressure with a gauge you can get a more accurate comparison. Keep up the great work. Sorry I dont comment more often but Ive been having to do quick views here and there on my phone during these busy times.

@OldeCarrGuy

3 жыл бұрын

Thanks for the tips Victor

@davelowets

2 жыл бұрын

Only if you have a 4-speed automatic. The governer and vacuum modulator control shift points and line pressure on a 3-speed auto, not the cable. The T.V. cable on a 3-speed only controls kick down and the trans will survive just fine without it even present. The cable on a 4-speed MUST be present AND adjusted correctly, or you will burn the transmission up in a few miles, usually less than that.

@Harrybowles1969

2 жыл бұрын

Yup run the proper 700r4/quadrajet linkage and check it's fully tight at full throttle.

I always liked the sound of the secondaries on my 1977 Newport 400 V8 with the Carter Thermoquad.

@OldeCarrGuy

4 жыл бұрын

Yip! I’ve already flipped the air breather! 😂

@thatbiguy1975

3 жыл бұрын

watch a lot of older car chase movies and you'll hear that quadrajet howl from cars that never had one.

@jsteganius6969

2 жыл бұрын

Thermoquad is a good carb. Give them some good attention and they work nicely.

Great video Jason

@OldeCarrGuy

4 жыл бұрын

Thanks bud

Awesome video thank you

@OldeCarrGuy

4 жыл бұрын

Glad you enjoyed it

Thanks for doing this comparison. A properly adjusted Qjet runs very well. For everyday driving with that truck its probably the best choice. Its an automatic, probably a Turbo Hydramatic 350 or 400. They upshift very quickly. The smaller primaries in the Qjet will also get better around the town mileage. (11 miles per gallon instead of 12 hahaha) An important note, the Qjet secondaries are huge. They open base on engine load and vacuum. If you don't get the rpm's up over 4 grand they will not open. Your truck is shifting from 1st to 2nd below 4 grand so the secondaries are not even opening. This test would yield better results if you were to manually shift your automatic and bring the rpm's up to 5200 rpm or whatever the redline is for your engine. You will actually hear the secondaries open and feel the kick.

@OldeCarrGuy

2 жыл бұрын

This transmission is quite literally straight out of a junkyard and was labeled NFG. I had my father, a 30 transmission mechanic, tear it apart to find out why and couldn't see any evidence of why it was bad. So we threw some seals and gaskets at it and called it good. Its a 700R4 in a truck that originally only had a TH350 so I can't manually shift it into 1st without modifying the steering column. We will get that 1-2 shift issue fixed this year so she pulls off the line better. Thanks for watching and commenting.

Great video buddy, 👍🤘🤙🏻✌️👊🏼

@OldeCarrGuy

4 жыл бұрын

Thanks bud! 👊

Don't give up on that quadrajet. I just rebuilt my friends 17080206 1980 qjet. It was a transplant to a 1971 k20 Chevy truck. I swapped the hot air choke for an electric choke conversion. Other than that complete rebuild. Not so bad. I was careful about everything. I do recommend quadrajet power LLC out of Texas. They really seem to be the Quadrajet experts. Thorough and professional all the way.

@OldeCarrGuy

2 жыл бұрын

I hear what you're saying Bob. I do like he Qjet over the 1406.

Good comparison

@OldeCarrGuy

4 жыл бұрын

Nothing like a back to back challenge!

Excellent idea! Qjet is the way to go!

i don't hear the secondaries the chokes secondary lock out probably isn't disengaging.

The snappy throttle response is the super small primaries. The bog is when the secondaries open and there isn't enough air velocity to atomize the fuel being dumped into the engine. The q jet is a very finicky carb to tune and make run well. Hence, why edelbrock has sold and continues to sell thousands and thousands of the 4 barrel Weber carb. I just wish they would have designed and sold a q jet patterned base plate version, so as to not have necessitated an adapter or manifold change.

People who say the quadrajet is junk, don't know how they work and can't adjust them correctly. Everyone I've ever had has worked perfectly, because they are tuned correctly.

@OldeCarrGuy

2 жыл бұрын

I enjoy the Qjet.

@jku72

11 ай бұрын

How did you ever get them to not leak down? Every one I’ve ever had is an absolute b- to start up and needs to crank over forever to refill the fuel bowls. Epoxy on the plugs works about three weeks before they leak again.

I hate to be the odd duck however. The Edlebrock carb is essentially a Weber carb. They are extremely reliable and off road race proven. They require some tuning. I’m Edlebrock all day long, used to run dual webers on a hot vw bug. You can’t beat them, Q-jet is also phenomenal but more finicky ! My two cents. I’m 61 and love muscle cars n trucks. Go Edlebrock

@BigWill63

Жыл бұрын

Edelbrock is a Carter AFB.

@gkauto1959

Жыл бұрын

I second that choice! I used to use holleys to run 1/4 mile races, tried the AFB and found out first hand they ran faster, used less fuel doing it and never lost their tune! Plus for daily driving they are more reliable overall than the QJet, which wind up leaking fuel down the manifold and getting their various air bleeds and passages clogged sooner or later! The AFB is the best choice of carb you have out there and are easy to tune and troubleshoot.

This is kind of a "BS" comparison between carbs here, I say that because it looks like neither of these carbs were tuned properly especially that Q-jet. Give me that Q-jet and dial in the air fuel mixture and the secondaries and it would perform infinitely better I'm sure. I did enjoy the vid none the less, maybe another video with both carbs tuned correctly?

@OldeCarrGuy

3 жыл бұрын

Sadly, you aren't the first one to make that comment ad I'll be the first to admit i'm no carb tuner! Thanks for watching and I appreciate the criticism just the same!

The 4MV (4-barrel Multiple Venturi) Quadrajet was THE MOST advanced all mechanical 4-barrel carburetor to ever see mass production. It's a shame they were all so *amned unserviceable. All the baseplates and transition circuits were application specific. The throttle rods didn't have serviceable bushings... so when they wore out, they would get finicky from the inconsistent vacuum leak. The metering rods were confusing as hell, because the spec numbers were year-specific... meaning you could have two sets of rods with the same identifier, but two different profiles. They were so precise in metering, but flexible at the same time. My favorite example was the 1970 X-SF code Buick 455. The exact same engine and build code was used in both the Electra 225 and Riviera... but the carbs were tuned differently. They used the exact same application code and tag... but they also had a "paint code"... a small brush stroke of different colored paint on the main body to denote the difference between the two apllications. One would work on the other... but would give you a headache on a seasonal tune-up if you had the wrong one. Despite my being a Q-jet fanboy... they suck for modern gas. Ethanol gas can't take the heat, and eats the seals/gaskets for lunch. It's not an issue you can tune/adjust out.

5.9 magnum to carburetor conversion here with mild cam in a 51 dodge . I'm a old carburetor tuner and I switched from a 600 edelbrock to a 600 holley dp is like night and day , lays rubber no brake stand , I just wish I didn't part with my q-jet so I can do a similar comparison . Dont get me wrong the edelbrock was running very well but just didn't have that snap that I wanted .

Qjet haters are just people that really have no clue or idea of how to tune one. They are about as simple as simple gets and the versatility is beyond this world. It wouldn't be installed on 10 million GM cars if it didn't work. Its hands down the best carb ever designed... What happened with the follow up vid?

@OldeCarrGuy

2 жыл бұрын

Unfortunately there was no dedicated follow up video, however, because my videos are a vlog style, I likely mentioned it in a later video. Sorry! But I did convert the truck to EFI! Thanks for watching

@timsharpe3498

2 жыл бұрын

Don’t forget about all the QUADRAJETs Ford and Chrysler put on their cars and trucks.

@BigWill63

Жыл бұрын

Actually, we made over 130 million Q-Jets.

85% of the people on the internet calling them "Quadrajunk" are 15 year olds who still eat boogers.

Has that fuel injection response. That sharp response is what im used to. They are picky about timing and vaccuum leaks though whereas i mean it also works like tbi/fi too bc it can actually use more fuel with a vaccum leak depending on setup because the metering rods are very very vacuum sensitive. Better mpg too. Ive had a couple myself. My squarebody has one. As long as they are built and adjusted right. Just make sure there is absolutely no leaks because it was deaigned around an almost perfect ratio based on engine load & vacuum. And make sure timing is alright since that greatly affects vacuum and how far throttle is opened to idle. They like around 725-800rpm idle. I got mine set at 755. And it only gets 12mpg 9n my 350 with a rv cam and .030 over due to it being a 3 speed 4wd by choice. I like the th350. Heavy cars and big engines at high highway rpms love fuel. It sees 75mph on ocassion and runs 3.73s so i dont consider 12mpg bad for that. Hard to count mpg in town though. Espescially depending on idle stop time. But i beleive it runs great. And i have to say the qjet is actually good for a fact it all boils down to if everything is set to where it likes it because theyre a bit on the particular side.

@OldeCarrGuy

3 жыл бұрын

I couldn't agree more. I have since installed EFI on my Square. I'm up to 14.5 mpg but it too needs some fine tuning. Thanks for watching and engaging. Please consider subscribing and liking the video.

@davelowets

2 жыл бұрын

A properly adjusted carb will have BETTER throttle response than F.I. any day.

@SOU6900

2 жыл бұрын

Wow 😆. My 86 K2500 only got 11 mpg in the summer and 9 in winter. That's with a reman 350 with a 700R4 and... 3.42(?) Gears in the front and rear diffs. Now if I can get that kind of mileage out of my 85 C30 with its 454/TH400/4.10 setup then I'd be really happy.

Im running a thermoquad , it's snappy

I love Quadrajets. Try mounting it backwards.

Which phone app were you using when you did your 0-60 runs?,,,

@OldeCarrGuy

2 жыл бұрын

On my iPhone it's called "0-60"

Don't listen to the haters. Rock that Q-Jet and don't look back.

I had high hopes that you would show the swaps in close up. I've got a 1980 G20 van that has an Edelbrock in it right now - the shop says the Edelbrock is for performance and the way everything is set up, they can't time the engine without a quadrajet in it., So I went to O'Reilleys and bought a Quadrajet. The two carbs look entirely different to me, the hoses, etc. dont go to the same places ..... and I'm NOT a carb man - so that's why I'm on U-Tube to find out how to swap them out. Good video, hope you get things hashed out so your truck will run right. Thanks.

@OldeCarrGuy

2 жыл бұрын

Thanks Mark!

@SOU6900

2 жыл бұрын

If you've still got the emissions sticker showing what goes where that'd probably help you out alot.

A Holley 800 CFM spread-bore double pumper like LIST# 6910 is the best of both worlds.

What was the name of the speedometer app that you were using?

@OldeCarrGuy

Жыл бұрын

Sorry Robert! I don’t recall!

Back in the day. I think guys felt you had to have a Holley! Not sure why? Maybe it’s the cool factor. So these guys would buy an 850 double pumper, drop it in an essentially stock engine, and pretend they had a fast engine.my 69 nova was bone stock 350 quadrojet.it was always so enjoyable beating them!

Sounds like you like the q-jet. It doesn't have an automatic choke? All mine had automatic mechanical chokes. Do you have a favorite app to test the acceleration?

@OldeCarrGuy

4 жыл бұрын

It does have a mechanical choke, I just didn't have it hooked up at the time. I had to modify it to work on the Performer RPM intake. I don't have a favorite app, or at least one I like yet!

@davelowets

2 жыл бұрын

Q-jets all came with automatic chokes. There were several different varieties of choke designs. There were electric chokes, and thermostat chokes of a few different configurations. The electric choke carbs would work on any engine, as all they need is a 12 volt power source. The thermostatic choke carbs had to be selected for the type of system that the particular engine has for getting the hot air from the engine to the choke.

@HarleyPebley

2 жыл бұрын

Yeah, by "automatic mechanical choke" I meant the thermostatic ones. No electronics needed but no manual intervention either.

@davelowets

2 жыл бұрын

@@HarleyPebley Yep lol, and if it's not the correct configuration to be able to hook up to the hot air supply, then you have to just wire it open so it doesn't flap around on you. If the choke linkage isn't fully open, and tight at the end of it's open travel on a Q-jet, the secondaries will not open either.

Shift kit so you can rev her out more? Im running 350 700r4 and shift kit and I'm real happy with the way it runs in my 69 c10

@OldeCarrGuy

2 жыл бұрын

Definitely!

I'm running a 750 QJ on my 491 Olds, and your carb needs service. I dyno'd at 620hp 570trq and was an edelbrock believer until I was shown the way with a QJ. I gained 30hp and 18trq switching to a slightly modded QJ. Also, get 3 mpg on the highway more and 1 in the city versus an 850 eddie. Also ran a 750 Edelbrock and gained a little up top but lost big time down below. Olds motors prefer down low anyways. I also know it truly depends on what motor you're running. That's my experience, though. Also, I do have to run a solid fuel delivery system. Mechanical pumps alone won't work on big cubes

@OldeCarrGuy

Жыл бұрын

Great Info! Thanks for sharing!

What better for my setup edelbrock or quadrajet I’m running a stock 305 engine n my Monte Carlo ss any suggestions anybody

@OldeCarrGuy

2 жыл бұрын

When setup properly either one makes a great carb. I preferred the QUad on my 350.

Are the secondaries opening? Doesn’t seem to be.

@OldeCarrGuy

3 жыл бұрын

You can't hear it on video, but they were indeed.

Is that wide open throttle, it is shifting at like 3,000 rpms and already in 3rd gear before 60mph. either his 700 R4 cable is adjusted wrong or the throttle cable is not opening the carb even close to wide open.

@OldeCarrGuy

3 жыл бұрын

It is a 700r4, but out of a 4 cylinder Astro van so its shifting way to soon into 2nd. TV cable is set perfectly, but the 1st gear is so short in these 4 cyl models i have yet to change the governor spring.

@Harrybowles1969

2 жыл бұрын

Yea new governor or shift kit

I drag race and have built many circle track cars. With that said i prefer quadrajets over carter and over all economy holley carbs. Now high end holleys with double pumper and adjustable air bleeds do perform bretter than quadrajets. But for anything under a thousand dollar carb id take a qjet every time. 750 qjet for smaller displacements and the 850 qjet for larger engines or very spicy small blocks. Works exceptionally every time

How did u find the part throttle, it’s the smaller primaries does it feel weaker, a lot of people say u get better signal but all performance are like Edelbrock and Holley have larger primary and I believe they give a better half throttle power, let me know what u think since u drove them back to back

@OldeCarrGuy

4 жыл бұрын

I find the Qjet to be very responsive all the way through the throttle, once you get the kick-down adjusted right. I'm liking the Qjet better than the Edlebrock so far, but I'm really interested to see if my fuel economy increases.

@glennmanchester9151

3 жыл бұрын

It will a improve a bit you cant expect miracles but it will give you better milage if you stay out of it ..

@davelowets

2 жыл бұрын

The smaller primaries will give you better torque, and better response at low RPMs. When you want all out power, the huge secondaries will provide all you need. Great carbs!

As I suggested before, remove the secondary kick down rod, then adjust the secondary butterfly to iliminate the "Bog"......

@OldeCarrGuy

4 жыл бұрын

I’m getting there! Gotta get it to idle properly with a solenoid first! A/C bogs it pretty good!

@gregghls2998

3 жыл бұрын

But the boooooogggg is what qjets are famous for lol

@briansd2772

3 жыл бұрын

I'd still use the choke pull-off and link rod. It functions as a damper to keep the air valves from bouncing and flopping open uncontrollably. The wind-up spring provides a preload but you really don't want it doing all the work. Use a quicker opening choke pull-off or modify one to help fine tune the air valve opening rate for performance driving. Typically a 1.5 to 2 second opening rate gets the job done. You do not want to feel the secondaries "kick in" hard. When that happens, your car is actually SLOWING DOWN momentarily due to a lean condition until the air/fuel mixture catches up.

Rochester Slobberjet., the absolute best OEM carb ever built. The trick is knowing how to tune and adjust them.

If you are having back fires you need to check and adjust your ignition timing. Also get an Quadrajet with an electric choke. Much better in the morning. Take care.

@OldeCarrGuy

3 жыл бұрын

This is all very temporary as I am likely switching to EFI over the winter.

@Harrybowles1969

2 жыл бұрын

Nooooooooooo! Quadrajet is awsome and reliable 😭

The Qudrajet carb is unbeatable when it's right......

If it's bogging & backfiring it's running lean, the secondaries accelerator system needs work.

My idle stop solenoid on my 68 quadrajet has only one function, to stop dieseling after I turn off my engine. It doesn't increase the idle if needed.

Any update on the fuel mileage change after the swap?

@OldeCarrGuy

3 жыл бұрын

I think I got better mike with the Edlebrock to be honest! I was able to get 17 mpg out of it once. Best I get now is 14/15.

@nashvilleoutlaw

3 жыл бұрын

@@OldeCarrGuy would be cool if you had an afr gauge to monitor and tune to. I really want to rebuild the one that was on my high school car. I never knew there was so much to tune on a quadrajet to make it right.

@SOU6900

2 жыл бұрын

@@OldeCarrGuy May need a bit more fine tuning.

@nashvilleoutlaw

Жыл бұрын

​@@OldeCarrGuyi stumbled on this video again. At some point quadrajet's started coming with APT (adjustable part throttle). If yours has APT you need to remove the top section to drill and tap it to be able to tune for your application. But it allows you to set the fuel ratio at part throttle aka cruising. 14.7:1 is supposedly as lean as you want to run an engine without loosing power as long as it doesn't cause detonation with your engine. That's on a separate circuit than your primaries and a quadrajet built right is very specific to the engine it's going on unless it's the bone stock engine with the original carburetor.

I’m in a debate on replacing my original q jet with another. Only reason why I don’t rebuild is because the secondary screw is froze up and they’re loose. I know it’s going to be more of a pain to rebuild in my limited space.

@OldeCarrGuy

2 жыл бұрын

If you can tune it, it will definitely be the better carb.

@zragevii4705

2 жыл бұрын

if you ever wanna get rid of it... I like quadrajets...😂

@SOU6900

2 жыл бұрын

@@zragevii4705 😆 I was about to say the same

some people swear by quadrajets but Ive always been an Edelbrock guy myself

@brianrayner676

4 жыл бұрын

Floyd's Mayhem Garage yeah, I like Carters too.

@OldeCarrGuy

4 жыл бұрын

I was an Edlebrock guy until now! Such a noticeable difference!

I’m having trouble with my classic. My car will only stay running if u spray the carb with starter fluid. Only way for it to stay running is if the rpm is put to 1,500rpm. And that’s only on park. Once I put it in reverse and or on drive it’ll start shutting off. only way is the starter fluid , i Manually have to keep spraying starter fluid.

@OldeCarrGuy

Жыл бұрын

Shounds like it's not getting fuel. Check to see that the fuel filter isn't plugged. If that's good, bypass the mechanical fuel pump with an electric one.

@musicvideos5212

Жыл бұрын

@@OldeCarrGuy thank you 🙏 will try that out asap

@musicvideos5212

11 ай бұрын

@@OldeCarrGuyupdate. Replaced the fuel pump (with a mechanical pump) and it’s still shutting off. I have a couple people telling me it could be the steering column or fuel sending unit. not sure at the moment what could be the cause. I still have to gas it n raise rpm just for it to stay on. not sure if it’s a carburetor problem.

I'd kill for a 9.9 0-60 in the Fairmont! Dale was just made to do burnouts!

@OldeCarrGuy

4 жыл бұрын

We're only assuming my app is accurate! I haven't found one I like yet.

@Str8sixfan

4 жыл бұрын

@@OldeCarrGuy yea I'll be interested in how I feel about the one I'm using when it comes a 3rd time around. I liked it the first time. But haven't trusted it since.

Q jets still kick ass.

@OldeCarrGuy

2 жыл бұрын

Agree!

I absolutely love the Q jet! Can't beat that moan!

I am curious to know why you do two passes for each. Vs 3. I always did 3 passes for comparisons and averaged them out. To me that helps illuminate flukes more. If your first run is a fluke and your second isn’t. You don’t really have a 3 rd to compare with for consistency. I my opinion (and it has been known to be wrong at least once I think). You need three or better yet even 5 because you want consistency.

People that bitch about q jets don’t even know what they’re bitching about, they can’t give 1 definitive answer about what they don’t like about them. I have one on my truck right now, it works ok, could use a rebuild but so can the whole engine, make the best of what ya got

@OldeCarrGuy

2 жыл бұрын

I'm Just afraid to learn. lol But I'm gettin better.

@jku72

11 ай бұрын

Leak downs. That’s pretty definitive, and something that happens to ALL quadrajets eventually.

I thought the 700 r4 like in a 90's z-28 for example was a 3 speed witha overdrive gear .I know it has the lock-up is that what you are counting as 4th?

@OldeCarrGuy

Ай бұрын

It is a 4 speed. The 4th gear is overdrive. The lock up converter is in addition to overdrive!

@EvanBarr-uk3vk

Ай бұрын

@@OldeCarrGuy thanks

The back firing could also be your accelerator pump is not squirting enough fuel. I installed an Edelbrock one and it works much better. It's just a little shorter so the cavity can fill with more fuel. Keep us updated. Later.

@OldeCarrGuy

3 жыл бұрын

Good to know!

If quads didn't work why did pontiac put them on 455 superduty TA's that kicked ass?😮 Get somone that knows Quadjets carbs to tune it. You might be surprised.

I don't like these comparisons as you don't know what the fuel mixture is between the two. Get the carbs properly tuned and use a wideband to show that both are running within a reasonable range for comparison. In the end if both are setup correctly I doubt you would notice much of a difference in the power range that truck is running.

I'm not sure how a poorly tuned q jet is supposed to compare to an edelbrock.

Need some wrinkle walls on that race car.

A tuned Qjet is a very responsive carb. Same for a tuned TQ

need to adjust your vacuum governor truck shifts to low

@OldeCarrGuy

2 жыл бұрын

Yeah, I sure do. It drives me nuts!

Cold blooded should be a non-consideration once the engine warms up. In fact the choke is fully opened well before the engine gets to operating temperature. All your drivability issues are related to the very poor state of tune of the carb.

I just aquired a quadrajet

Maybe, just maybe, instead of looking at the choke for the idling problem, look at the idle circuit.

U will need a 76 and up model to run electric choke

@OldeCarrGuy

4 жыл бұрын

This is my original Qjet in this 77 truck. It has a mechanical choke!

@grand73am

Жыл бұрын

73 and up have the choke housing on the carb body so you can easily install an electric choke.

Quadrajets are great

@OldeCarrGuy

Жыл бұрын

They sure are

Honestly they hate them becuase they dont understand them. They where put on daily and daily performance cars back in the day so they had to be responsive. Most wont understand how they are more responsive then the others but it was the design. The edelbrock rock was based off the carter afb which gm got away to go to qjet for a reason. Yea there old and out of date but i have gotten 20+mpg highway out of mine with the aod transmission thats still good for todays times i feel. I honestly think the adapter plate is choking it down a little. If you find one for a good deal a edelbrock rpm qjet intake would work great since you wont need the adapter plate and you could run a phonolic spacer with a heat gasket and really feel it.

@OldeCarrGuy

4 жыл бұрын

I’m definitely sold! Just need to tweak it and I’m sure it’ll be a monster!

@EfurdGarage

4 жыл бұрын

@@OldeCarrGuy considering its already an improvment yea lol just take time tuning it it will be worth it.

@zragevii4705

2 жыл бұрын

My uncles religiously tells me a story of my grandpa getting 30mpg+ from his boat of a car because he had a qjet on it. Drive it like a grandma and get economy, and then pass everything when you step on it.

@EfurdGarage

2 жыл бұрын

@@zragevii4705 i dont know about 30, i guess if you do drive it like a grandma. My dail has a qjet with overdrive and gets about 20mpg at 60is mph

The edelbrock is the better choice if you don’t like constant maintenance. Overall, the quadrajet is better - when its not leaking down, bogging, or suffering from the myriad of problems that come up. If you have lots of time and don’t mind having to work on them once a month you can’t beat a q-jet. If you just want a carburetor you can install, set, and never think about again, get an edelbrock.

@Busta_Capp_

8 ай бұрын

No "constant maintenance" if its right! Wth..

@jku72

8 ай бұрын

@@Busta_Capp_ “if its right”. Which they rarely are, and don’t stay that way long. I have never owned a q-jet that didn’t leak down, and never had one stay in tune for very long, whether tuned by me or professionals. When they are dialed in, they get better gas mileage, marginally. After initial tuning, I’ve rarely had to touch an Edelbrock. I’ve had three, and had a float sink once. Other than that, they just work. Easy for a shade tree like me to dial in, and they stay dialed in. No weakening secondary springs that create bogs, no weird midrange leaning out, just consistent “good enough” operation. Perhaps you have better skills than me, I am a hobby mechanic who’s owned 15 or so quadrajet cars, and three Edelbrocks. The quadrajets ALWAYS had some problem, not always the same (except for leakdown, they ALL leakdown, even the 1986 G-10 q-jet I still have.). So I’m happy for you that quadrajets have worked out so well for you.

@Busta_Capp_

8 ай бұрын

@@jku72 YOURE FULL OF 💩 YOU DONT KNOW WTF YOURE TALKING ABOUT OBVIOUSLY! THEY ARE JUNK AFTER A FEW YEARS STOCK BUT IF YOU KNEW SOMEONE LIKE I DO YOU WOULD STFU TOO MANY PEOPLE MISMATCH THEM AND DONT KNOW WTF THEY ARE DOING LIKE YOURSELF BUT THEY ARE BAD ASS IN THE RIGHT HANDS ADED

@Busta_Capp_

8 ай бұрын

#1705 are the ones you want to start with..people have to know what they are doing not a half ass know it all mechanic...

There are MANY N.H.R.A. Stock and Super Stock cars that run the Quadrajet that are very fast. Anyone that knows anything about those 2 classes will tell you the same thing.

@OldeCarrGuy

2 жыл бұрын

Good to know!

4:42 All I think if when I hear that song: m.kzread.info/dash/bejne/o6N8usd6gZjRqZM.html 😂😂

@OldeCarrGuy

20 күн бұрын

😂😂

Choke isn't set right.

Holley

You gotta manually shift.

@OldeCarrGuy

2 жыл бұрын

I get that, but with the 700r4 conversion, I am unable to shift into 1st manually unless I modify the steering column.

DON'T HEAR THE BOG SECODARYS....

Why even have a video of a comparison between ANY two carbs if one of them isn't dialed in correctly? Sorry, but I don't see the point. A Q-Jet is a true spread bore, meaning that the two small main butterfly's are going to have more velocity and a superior bottom end response(spinning tires). To those talking about "bog" - two things, if the massive secondary's are opening too fast, yes, that can be an issue. Also, the float bowl is centrally located on a Q-Jet, so the fuel can get hot and cause an issue after more than an 1/8 mile. I've ran all three brands, Q-Jet is a PITA to get right sometimes, but if you do they are really nice. Edelbrock is something I like to throw on a mildly modded or stock motor just because they are easy to dial in and rather dependable. Holley is what I go for if I'm running a big cam, high flowing heads and am doing something with it wide open a LOT. Both dialed in correctly and tuned to the motor I think the Q-Jet is going to triumph, but it will take more effort to get it just right. That's my two cents. I leave with don't be a brand slave, make your own conclusions on your own experience. Looking forward to a video of them both properly dialed in.

@OldeCarrGuy

3 жыл бұрын

It wasn't my intent to show the Q in bad light, just in a bit of a hurry to get the video out. I definitely preferred the Q over the E especially now that it's dialed in. I recently installed EFI on this truck and will be comparing the drivability. Thanks for your concern and information. I definitely take it under advisement in the future.

@BigHatsince98

3 жыл бұрын

@@OldeCarrGuy Thanks for the reply! I'm glad you like the "Q"! I've thought about putting the holley sniper on my square body. I just think I'd be defeating my purpose for going old school to do so though! Looking forward the the next video. Hope I didn't come off rude, I just get sick of hearing about how "bad" Quadrajets are!

@chrisreynolds6520

3 жыл бұрын

Just went the other way on my 97 Express van. Ditched the sequential vortec EFI on the 350 for a Quadrajet and performer rpm on a 383. Quadrajet runs great!

I no for a fact that motor has wayyyy more rpm hold them gears

@OldeCarrGuy

2 жыл бұрын

It does indeed. As far as I know it’s a stock 700R4 and that 1st gear is real short.

Watching this it looks like the Edelbrock was the faster carb. This is good to know, I am shopping for a carb right now.

@OldeCarrGuy

2 жыл бұрын

Hope you enjoy it!

Sounds like those pills are bad for your tires lol

@OldeCarrGuy

4 жыл бұрын

Did I miss the reference?

@truckerdave5122

4 жыл бұрын

@@OldeCarrGuy pulls are bad for ties oy must have hits a bump

@truckerdave5122

4 жыл бұрын

Tires dang it

What is your engine combo? 0-60 in 7 seconds in a full size truck is QUITE impressive! Adjusting the secondary air valve till you can floor it without a bog is a big first step. Start at around 5/8 turn past zero and go from there. My Qjets usually liked 3/4 past zero.

@OldeCarrGuy

Жыл бұрын

It's a mild built 350 with a 700R4 and stock 3.73 gears. Before you go believing these numbers 100%, keep in mind i was using a free app, so i would likely give a 1 second margin of error or more. Either way, it does work good if you can hook up!

Should've sprung for a shave while you were at the barber. Chinese or Mexican carburetors aren't competitive with made in USA equipment.

@OldeCarrGuy

2 жыл бұрын

Why you hating on the beard bro! Maybe a lawnmower carb would be better?

@20alphabet

2 жыл бұрын

@@OldeCarrGuy I saw that lawnmower carb video, and was surprised by the success. Guess the Rochester QuadraJet goes to show that old Made In USA still trumps Chinese repops. Beards... lol.

I have Quadrajet on my 383 stroker it's working fine. Part of the small problem in the video is the change shift rpm point on trans cable, or install shift kit in 700R4 trans. It makes a super difference

@OldeCarrGuy

Жыл бұрын

I agree with the shift points. I believe my 700r4 may have been out of a 4cyl so.

omg..the Quadrajunk was a little faster after the stalling , flooding and huge bog Pass!

@OldeCarrGuy

3 жыл бұрын

I am completely aware that the app for timing i was using is not as accurate as it should be, but the q-jet does "feel" like it out preforms the Edelbrock when i did finally get it adjusted properly.

@davelowets

2 жыл бұрын

Biden Must RESIGN! You must not have any experience with a properly setup, properly tuned Quadrajet. They work better on the street for a mild motor than a Holley would.

What we’re learning is this guys driving is just as bad as his mechanical skilz

@OldeCarrGuy

11 ай бұрын

You may be right!

Video never gets started wasted time listening to talk talk talk talk and more talk so boring. Mic did not sound correct volume up and down.

@OldeCarrGuy

2 жыл бұрын

Thanks for taking the time to comment though!