Qjet Carb "custom mods?"
#1
Heel & Toe
Thread Starter
Qjet Carb "custom mods?"
Hey All! Been working on a rebuild of my '81 and after getting the new block assembled decided to turn my attention to the carb. Using what was on the car when I purchased it i decided to do a rebuild kit... when I got inside this is what I found... JB Weld?!? looks like someone intentionally closed up some of the ports?? Is this some sort of Bubba trick I don't know about. It worked before, so I just put it back together the way I found it with the new components in the kit. Lemmeno what you think.
#2
Melting Slicks
common practice to jb weld over the plugs so they wont leak. but i never have seen that much used. usually just the 2 center plugs.
#3
Those are the well plugs for the float bowl. Once in a great while they were known to leak. People JB weld them up to keep them from leaking. Most of the time it is not necessary, if they are leaking the proper way to fix them is drill them out and thread them for a pipe plug.
#5
Le Mans Master
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Qjets are "technologically" advanced. If they are set up properly (according to Lars' papers) they are as good as any carb. I've rebuilt two for my BBCs, and they scream. No bog, no hesitation, no problems. Instant throttle response. Just spins the wheels from a 20 MPH roll in 1st. The problems only start when Bubba starts ripping them apart and reassembling them without any idea of what he's doing.
#6
Burning Brakes
Just to be clear, q junk is not technologically advanced. On demand carbs have been used since the days of the wright bro.
The best, and most famous and successful are the SU carbs used on the racing jaguars.
Q junk is an inferior copy prone to warping, leaking, small float bowl, stripped threads and difficult tuning.
All of the above quoted in Lars' papers.
The best, and most famous and successful are the SU carbs used on the racing jaguars.
Q junk is an inferior copy prone to warping, leaking, small float bowl, stripped threads and difficult tuning.
All of the above quoted in Lars' papers.
#7
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Just to be clear, q junk is not technologically advanced. On demand carbs have been used since the days of the wright bro.
The best, and most famous and successful are the SU carbs used on the racing jaguars.
Q junk is an inferior copy prone to warping, leaking, small float bowl, stripped threads and difficult tuning.
All of the above quoted in Lars' papers.
The best, and most famous and successful are the SU carbs used on the racing jaguars.
Q junk is an inferior copy prone to warping, leaking, small float bowl, stripped threads and difficult tuning.
All of the above quoted in Lars' papers.
Jim
#8
Burning Brakes
What can be said about a carb that has to be filled with J B Weld to keep from leaking?
Why is it that Lars always has to answer Q junk issues?
Seriously, without being snarky or a wise guy, why is that? Whenever someone states something true about the Q it is immediately intimated he knows nothing.
The Grand Wizard On the Mountain Most Venerable Pooh Bah Lars will come to the rescue in his grand pooh bah suit?
God forbid anything ever happens to Lars. You Q junk guys will be up the creek without a Wizard.
#9
Racer
What is there to comment on?
What can be said about a carb that has to be filled with J B Weld to keep from leaking?
the same that can be said of a car that leaks or has rust issues: it needs maintenance. Nothing works perfectly forever.
Why is it that Lars always has to answer Q junk issues?
Because he is one of the few people here who seems to know how to fix a Quadrajet properly AND is willing to talk about it, rather than telling people to junk it like you so emphatically do.
Seriously, without being snarky or a wise guy, why is that? Whenever someone states something true about the Q it is immediately intimated he knows nothing.
I try not to make assumptions about what other people know or don't know. For what it's worth, I get the impression that you actually do know how Quadrajets work, and you've decided based on that that you do not like them.
The Grand Wizard On the Mountain Most Venerable Pooh Bah Lars will come to the rescue in his grand pooh bah suit?
if asked, possibly.
God forbid anything ever happens to Lars. You Q junk guys will be up the creek without a Wizard.
There's Cliff Ruggles as well, but I see your point: once they are no longer doing this Q-jet owners will have a hard time getting their carbs repaired until someone new decides to learn how to offer the service.
What can be said about a carb that has to be filled with J B Weld to keep from leaking?
the same that can be said of a car that leaks or has rust issues: it needs maintenance. Nothing works perfectly forever.
Why is it that Lars always has to answer Q junk issues?
Because he is one of the few people here who seems to know how to fix a Quadrajet properly AND is willing to talk about it, rather than telling people to junk it like you so emphatically do.
Seriously, without being snarky or a wise guy, why is that? Whenever someone states something true about the Q it is immediately intimated he knows nothing.
I try not to make assumptions about what other people know or don't know. For what it's worth, I get the impression that you actually do know how Quadrajets work, and you've decided based on that that you do not like them.
The Grand Wizard On the Mountain Most Venerable Pooh Bah Lars will come to the rescue in his grand pooh bah suit?
if asked, possibly.
God forbid anything ever happens to Lars. You Q junk guys will be up the creek without a Wizard.
There's Cliff Ruggles as well, but I see your point: once they are no longer doing this Q-jet owners will have a hard time getting their carbs repaired until someone new decides to learn how to offer the service.
You love Holley: that much has been made abundantly clear in your posts. And that's fine: having options is a wonderful thing. Other people here love Holley too. I just don't understand your visceral hatred for the Q-jet and why you seem compelled to tell it every time a carb thread comes up. Frankly, it gets old. You hate the Q-jet and love Holley. We know. We ALL KNOW. Commander_47 hates Q-jets.
I think everyone would be better served if you could just offer that replacing with a Holley is, in your opinion, a better option and then elaborating only when asked. Everyone else politely offers that repairing the q-jet should be considered before tossing it, as in some cases it can fixed cheaper than buying a new Holley or Edelbrock. Instead you come off as a small-minded wailer who should be ignored ever time you shout "It's junk! Junk! JUNK IT!" And that's unfortunate because from reading your other posts you clearly do know what you're talking about, but that's the feeling I walk away with, at least.
#10
Burning Brakes
Instead you come off as a small-minded wailer who should be ignored ever time you shout "It's junk! Junk! JUNK IT!" And that's unfortunate because from reading your other posts you clearly do know what you're talking about, but that's the feeling I walk away with, at least.
That is EXACTLY how I feel about the QJ harpies.
I've been on the forum for a couple of years and everytime anyone mentions anything OTQ (other than Q) they get pounced on by the same harpies who pummel them into the ground with their words.
So why doesn't your argument above apply to them?
It is very annoying.
Someone says they want to put a Holley on their car and suddenly the harpies come out with the same posts......over and over again:
DON'T DO IT!!!!!!!!
1. Q is the best!!!!!!
2. Send it to Lars for rebuild!!!!!
3. You don't understand it. Lars can fix it!!!!
4. Milions were made, it's the best, works constantly well!!!!
5. I have one on my race car and it's fast as lightning!!!!!
6. It's technolologically advance....you don't understand it....send it to Lars.
Except for the send it to Lars part, all of the above is not true.
Then, when facts are brought out, often verified the grand high wizard of the Q himself, they are totally ignored!!!! And the poster put denigrated.
If you are tired of hearing an opinion that doesn't agree with yours, then you know how some of us feel.
#11
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Hi Commando! It's good to see you in top form again - you were so quiet for a while that I was afraid you'd lost your enthusiasm and zest..!
The early year Q-Jets (1966 - 1968) had reliability issues with the well plugs: The plugs would start to drip after a couple of years in service, so every car magazine in the world wrote articles about the leaking plugs and ways to fix them. The later carbs, and especially ones like yours, never had the leaky plug problem, yet the myth about the plugs never died. There is no problem leaving the epoxy there, but I usually chip it off the carbs I rebuild. You can take your bare float bowl casting, set it up on some tall sockets on your work bench, and fill the float bowl with gas or alcohol. Let it sit for a few hours and take a look at the well plugs to see if there are any drops of fluid on them: I'll bet they'll be bone dry. The drip problem is very rare, and no action is required to rework the plugs unless you actually verify and witness that you have a leak.
Lars
The Grand Wizard On the Mountain Most Venerable Pooh Bah of Q-Jets
Lars
The Grand Wizard On the Mountain Most Venerable Pooh Bah of Q-Jets
Last edited by lars; 04-03-2015 at 12:18 PM.
#12
Instructor
What is there to comment on?
What can be said about a carb that has to be filled with J B Weld to keep from leaking?
Why is it that Lars always has to answer Q junk issues?
Seriously, without being snarky or a wise guy, why is that? Whenever someone states something true about the Q it is immediately intimated he knows nothing.
The Grand Wizard On the Mountain Most Venerable Pooh Bah Lars will come to the rescue in his grand pooh bah suit?
God forbid anything ever happens to Lars. You Q junk guys will be up the creek without a Wizard.
What can be said about a carb that has to be filled with J B Weld to keep from leaking?
Why is it that Lars always has to answer Q junk issues?
Seriously, without being snarky or a wise guy, why is that? Whenever someone states something true about the Q it is immediately intimated he knows nothing.
The Grand Wizard On the Mountain Most Venerable Pooh Bah Lars will come to the rescue in his grand pooh bah suit?
God forbid anything ever happens to Lars. You Q junk guys will be up the creek without a Wizard.
#14
Racer
It is ironic that you stated the above.
That is EXACTLY how I feel about the QJ harpies.
I've been on the forum for a couple of years and everytime anyone mentions anything OTQ (other than Q) they get pounced on by the same harpies who pummel them into the ground with their words.
I've never seen 'pummeling'. At most, people point out that the Q-jet can sometimes be rebuilt, and offer that going that route first might save money. Money that can be put toward other parts. I think we all agree that these cars have a voracious appetite for cash.
So why doesn't your argument above apply to them?
The argument does apply if they're harpies. I simply haven't seen one. People pushing the Quadrajet tend to be polite and accept when a person decides they'd rather have something else. If anything it means more Q-jets they can use to keep theirs going. It's the OTQ people that get bent out of shape when an OP says they want to keep their Q-jet.
It is very annoying.
harping always is regardless of who does it or why
Someone says they want to put a Holley on their car and suddenly the harpies come out with the same posts......over and over again:
I've never seen harping. Politely pointing out that the Q-jet may need maintanence rather than replacement, maybe, but never harping. I'll gladly eat crow if you can point me a few posts where a person has been browbeat for their decision to change carbs.
DON'T DO IT!!!!!!!!
1. Q is the best!!!!!!
A matter of opinion, and opinions and never right or wrong. Ill-concieved or misinformed, but never wrong. This non-constructive comment does an OP no good.
2. Send it to Lars for rebuild!!!!!
because it's often cheaper than buying a new carb, and most people like to save money where they can. This is sound advice.
3. You don't understand it. Lars can fix it!!!!
this is usually because people read a million comments about the q-jet being junk, when it clearly is not. If it was, Lars and Cliff would not have the success they have had in keeping them working. As Goebbels said, "If you tell a lie big enough and keep repeating it, people will eventually come to believe it." What the quadrajet people are trying to do is dispel a decades-old myth.
4. Milions were made, it's the best, works constantly well!!!!
Millions made is a fact. "Best" is an opinion, as pointed out in point 1. I've never read anyone say it works 'constantly' and do to so would be foolish. Point negated.
5. I have one on my race car and it's fast as lightning!!!!!
carb is only one factor. That comment is worthless without pointing out everything else done to make it 'fast as lightning'
6. It's technolologically advance....you don't understand it....send it to Lars.
aside from the 'technologically advanced part, this is the same argument you posted under point 3.
Except for the send it to Lars part, all of the above is not true.
opinions are neither true nor false, and some of the points are true.
Then, when facts are brought out, often verified the grand high wizard of the Q himself, they are totally ignored!!!! And the poster put denigrated.
You're right: Lars himself has pointed out that there are drawbacks to the Quadrajet and some people may be better served with a Holley.
If you are tired of hearing an opinion that doesn't agree with yours, then you know how some of us feel.
That is EXACTLY how I feel about the QJ harpies.
I've been on the forum for a couple of years and everytime anyone mentions anything OTQ (other than Q) they get pounced on by the same harpies who pummel them into the ground with their words.
I've never seen 'pummeling'. At most, people point out that the Q-jet can sometimes be rebuilt, and offer that going that route first might save money. Money that can be put toward other parts. I think we all agree that these cars have a voracious appetite for cash.
So why doesn't your argument above apply to them?
The argument does apply if they're harpies. I simply haven't seen one. People pushing the Quadrajet tend to be polite and accept when a person decides they'd rather have something else. If anything it means more Q-jets they can use to keep theirs going. It's the OTQ people that get bent out of shape when an OP says they want to keep their Q-jet.
It is very annoying.
harping always is regardless of who does it or why
Someone says they want to put a Holley on their car and suddenly the harpies come out with the same posts......over and over again:
I've never seen harping. Politely pointing out that the Q-jet may need maintanence rather than replacement, maybe, but never harping. I'll gladly eat crow if you can point me a few posts where a person has been browbeat for their decision to change carbs.
DON'T DO IT!!!!!!!!
1. Q is the best!!!!!!
A matter of opinion, and opinions and never right or wrong. Ill-concieved or misinformed, but never wrong. This non-constructive comment does an OP no good.
2. Send it to Lars for rebuild!!!!!
because it's often cheaper than buying a new carb, and most people like to save money where they can. This is sound advice.
3. You don't understand it. Lars can fix it!!!!
this is usually because people read a million comments about the q-jet being junk, when it clearly is not. If it was, Lars and Cliff would not have the success they have had in keeping them working. As Goebbels said, "If you tell a lie big enough and keep repeating it, people will eventually come to believe it." What the quadrajet people are trying to do is dispel a decades-old myth.
4. Milions were made, it's the best, works constantly well!!!!
Millions made is a fact. "Best" is an opinion, as pointed out in point 1. I've never read anyone say it works 'constantly' and do to so would be foolish. Point negated.
5. I have one on my race car and it's fast as lightning!!!!!
carb is only one factor. That comment is worthless without pointing out everything else done to make it 'fast as lightning'
6. It's technolologically advance....you don't understand it....send it to Lars.
aside from the 'technologically advanced part, this is the same argument you posted under point 3.
Except for the send it to Lars part, all of the above is not true.
opinions are neither true nor false, and some of the points are true.
Then, when facts are brought out, often verified the grand high wizard of the Q himself, they are totally ignored!!!! And the poster put denigrated.
You're right: Lars himself has pointed out that there are drawbacks to the Quadrajet and some people may be better served with a Holley.
If you are tired of hearing an opinion that doesn't agree with yours, then you know how some of us feel.
All you ever say is it's junk and that Holley is better. Holley isn't better. It's different. If you want to disagree that's fine: but the screaming has gotten old.
#15
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Now that's some seriously funny stuff right there..! I have a vision of what that tight, superhero suit looks like, and I'm going to make me one and wear it to the bar some day when you and I have a drink together...!
Lars
#16
Many years ago, building cars in the garage on Saturday morning I used to watch the WWF on the TV. One of my favorite characters (wrestlers) was Hacksaw Jim Duggan. He used to run around the ring with an American flag and a length of 2x4. Hacksaw's bitter enemy was the Iron Sheik who ran around with a foreign country flag. Needless to say the Sheik got lots of negative feedback. These two where like bitter enemies on Saturday mornings. One day I picked up the newspaper to read that the Iron Sheik and Hacksaw were riding together in a Caddy on the Jersey Turnpike and got pulled over by State Troopers. There was no mention of how the Caddy's Q-Jet was running.
#18
Le Mans Master
When I got my '80 in May 1997, it was tired with 96k miles but had much of its engine parts intact. I had a mechanic neighbor do a $25 NAPA rebuild on the carb to give it a refresh. The car ran fine as far as a bone stock L48 goes but when it came time to measure the benefits from improvements to date (2002), I took the car to a 'forum tuner day in Clearwater, FL. After a couple pulls, I was really disappointed to see only 190rwhp and about 240rwtq. I paid another $175 as the tuner said he could help... The guy ground off the metering rods and pretty much made them garbage; yeah, the car was more responsive but exhibited other low/slow idle issues (oh, he also laid down a really good advance curve... that was the source for the performance improvement).
This was something like 13-16 years ago (1999-2002 repairs all run together now as I was constantly doing something to the C3). that was when the 'forum was in its early days shortly after many left the Yankee Lady site when they started to charge membership.
I heard about this guy 'Lars' that was a carb and distributor tuner with a bar and shop in his home garage. For about $250 including return S&H, he would set your carb up, fix its ills, tune it on his mid-year and send it back with support. He discovered the destroyed metering rods, linkage, and other issues and informed me that it was a service replacement carb. I had some repair history that supported the carb installation from a dealer when one of the nine PO's started having original carb issues.
I think he set it up with new jets and metering rods, tuned it and tested it following repairs. I may have had to swap the secondary metering rods (he shipped complimentary with the carb just in case mixture adjustment would not be enough).
Yeah, I could have bought a Holley but figured this was a great way to learn more about the C3. I've not had a need to make any carb changes since then and I've made a number of good improvements to the engine, exhaust and drivetrain.
I have considered sending it off to Lars just for a refresh to make sure it is still in good working order since I run it regularly on E10 and it sits more than is driven.
The carb meets my needs. There are enough of us on this forum (and likely others) that will recommend Lars as he has done a great service to our hobby cars. If there were no 'Lars' to rebuild my carb, the car would probably have a poorly tuned qjet or a Holley.
If I ever pull the carb (replacement), it will be for some newfangled fuel injection system... but that will be another 8-10 years and something I'll do with lots of time on my hands (retirement) since it will involve a new fuel delivery system, electronics (perhaps even some new digital gauges and fuel/air sensors) and underhood updates. It will have to be flex-fuel like the newer cars and not just tolerate E10 or E15.
This was something like 13-16 years ago (1999-2002 repairs all run together now as I was constantly doing something to the C3). that was when the 'forum was in its early days shortly after many left the Yankee Lady site when they started to charge membership.
I heard about this guy 'Lars' that was a carb and distributor tuner with a bar and shop in his home garage. For about $250 including return S&H, he would set your carb up, fix its ills, tune it on his mid-year and send it back with support. He discovered the destroyed metering rods, linkage, and other issues and informed me that it was a service replacement carb. I had some repair history that supported the carb installation from a dealer when one of the nine PO's started having original carb issues.
I think he set it up with new jets and metering rods, tuned it and tested it following repairs. I may have had to swap the secondary metering rods (he shipped complimentary with the carb just in case mixture adjustment would not be enough).
Yeah, I could have bought a Holley but figured this was a great way to learn more about the C3. I've not had a need to make any carb changes since then and I've made a number of good improvements to the engine, exhaust and drivetrain.
I have considered sending it off to Lars just for a refresh to make sure it is still in good working order since I run it regularly on E10 and it sits more than is driven.
The carb meets my needs. There are enough of us on this forum (and likely others) that will recommend Lars as he has done a great service to our hobby cars. If there were no 'Lars' to rebuild my carb, the car would probably have a poorly tuned qjet or a Holley.
If I ever pull the carb (replacement), it will be for some newfangled fuel injection system... but that will be another 8-10 years and something I'll do with lots of time on my hands (retirement) since it will involve a new fuel delivery system, electronics (perhaps even some new digital gauges and fuel/air sensors) and underhood updates. It will have to be flex-fuel like the newer cars and not just tolerate E10 or E15.
Last edited by TedH; 04-06-2015 at 03:13 PM.
#19
Team Owner
We all know the "Commander" doesn't like Q-Jets. So why does he continue to dump his BS where no one cares?
The best solution is to simply ignore ignorance.
The best solution is to simply ignore ignorance.
#20
Burning Brakes
Fact is, once again I'm proven 100% correct, and YOU are the ignorant one.
Q junks, leak. Oh, wait, only the early ones according to Grand Vizeer Pooh Bah of the Q.
So another one of those cute idioisynchrosies that you all love about the Q; Making sure you don't get an early junk because you'll have to pack it full of J B Weld to keep it from leaking.
This used to be normal procedure with the junk:
This was common. And it can be debated that not just the early ones have this issue.
The warpage these things are famous for is responsible for many many many leaks.
Some say this is due to guys tightening down on the top screws too much. But what is too much? I'm here to tell you.....it doesn't take much. And I know this from experience.
There are many of us, myself included, who believe that overtightening may cause SOME of these leaking issues, but bad metullurgy is more likely the culprit.
Simply because these carbs strip threads just from overuse!!!!! Not abuse.
And as for those rods being ground down that are mentioned in an above post????? Another common, common commmon issue with these.
Why was this done? Simple, to enrichen the mixture. To make it perform like an off the shelf Holley.
A better way is probably to adjust the APR setting so the rods are higher or lower, thereby richening the mixture earlier or later in the vacuum cycle.
If memory serves me, this is a little harder to adjust on the later models because there is cap over the adjuster. And you need a slotted tool to adjust the screw.
This is all MOST tuners do to improve the performance of Q junk. They simply force the carb to run a little richer........like a Holley.
Making it run a little richer sort of removes all the benefits of running a smog carb doesn't it? Oh, it may still get decent mileage, but better than a Holley and with all the issues associated with it?
The Carb has a small float bowl. Any sort of spirited driving runs the risk of NO FUEL. That's right. the fuel sloshing around in the float bowl due to centrifugal force doesn't get to the engine.
Ask circle track guys.
Then there's always the guy who jumps in and says..."MY CAR with a Q junk is a ROCKET at the dragstrip" Hooey There isn't a q jet at the track that can stand up against a Holley.
The Grand Pooh Bah himself likes the Holley XP series.
All Holleys, and Holley clones (Demon etc) are based on the venerable 4150 body. A 100 years plus body design that continues to this day to be the standard by which all carbs are judged.
The "on demand" carbs have long ago fallen by the wayside. Including the top of the line SU series, of which Q junk is a poor, sad, inferior copy.
I understand those with classics that want to maintain their "numbers" correct cars. Believe me, I do. I have been known to spend ridiculous sums of money on parts for an original vehicle.
But remember this.......there aren't any "classic" q junk carbs. Even the so called rare 800 cfm q junk is a myth. These were put in TRUCKS.
That's right. Trucks. Thousands of them. But one that is "numbers" correct for your application might be rare. Of course, you can scour the junk yard for a suitable rebuildable body from a donor Suburban and have the correct carb, just not the numbers.
I know, I know, I'm ignorant. I don't understand how "technologically" advanced the q junk is.
More like Technologically retarded.