Quadrajet or Demon

[ofnaman]

I have been debating this for a while now, but need some help choosing. I have a cammed out 402 in my '70. I have had good luck with both, but really liked my old demon. I have been thinking about the quadrajet for the gas mileage, but would I gain enough mileage to be worth it? Thanks

[joedoozer]

I love Q-jet carbs. A bit complicated if you have never worked on one. But with a good book, and a little patience. I don't think there is a better street carb.

[retselgerg]

QJET....plain and simple

[chipflyer]

Got to agree, quadrajet is at the top of my list.

[fastom]

I love Demon carbs, I have three of them. When I started on my truck and was doing my homework on all the parts I needed and wanted I never even thought about the carb, it was going to be a Demon.

I've thought about it this way. Every Q-jet is used and is at least 20 years old and the carburetor I buy from Berry Grant is brand new with a warranty and tech support. A Q-jet won't be any better on mileage than the proper Demon carb correctly tuned. The Demon carb will also out perform the Q-jet in a performance application.

[Jim_PA]

Originally Posted by fastom

I love Demon carbs, I have three of them. When I started on my truck and was doing my homework on all the parts I needed and wanted I never even thought about the carb, it was going to be a Demon.

I've thought about it this way. Every Q-jet is used and is at least 20 years old and the carburetor I buy from Berry Grant is brand new with a warranty and tech support. A Q-jet won't be any better on mileage than the proper Demon carb correctly tuned. The Demon carb will also out perform the Q-jet in a performance application.

Does the demon have some type of metering rods that lean out the mixtures at cruise and idle? Most (if not all) aftermarket carbs dont, so it's hard for me to believe you can make one as efficient as a qjet.

If it's for the street, you won't notice the HP difference. I've seen several dyno comparrisons where the qjet makes more power/torque down low, and stays right with the aftermarket carbs on the top end.

[72swb_327stroker_?]

DEMONS ROCK!!!
i have a few demon carbs on different things and they are the best!
demon carbs are an evolved holley carb with all the upgrades done, and all the problems eliminated. as for q'jets being the best "street" carb? hmmmmm?????

i think its a matter of preference and opinion when you go to a voters pole, but if specs and performance numbers mean anything to ya,
go with the demon!

well lets see both

barry grant demon series carbs=
tuning=easy...........................+1pt
floats w/sight glass & adj/outside..+10pt
rebuilding=easy+cost friendly...+1pt
price=reasonable ..................+1pt
parts=everywhere.................+1pt

+
______________________________
= 14 points for the demon

quadrajet factory stock carbs=
tuning=pita...................-1pt
floats=??pita................-10pt
rebuilding=pita..............-1pt
price=reasonable...........+1pt
parts=good luck............-1pt
+
___________________________
= -12 points for the q-jet

[tnblazerk5]

q jet
if it is rebuilt the proper way it will out perform the demon
i use to have a web page(lost it when puter died a few years ago) where they took the same motor and used a qjet and a holly and a demon and sumthing else and the qjet outpreformed them all and made more hp seams to me they even had a write up bout this in hotrod mag a while back

[jamon8]

quadrajet factory stock carbs=
tuning=pita...................-1pt
floats=??pita................-10pt
rebuilding=pita..............-1pt
price=reasonable...........+1pt
parts=good luck............-1pt
+
___________________________
= -12 points for the q-jet
[/QUOTE]

ok I have never had a demon so I will not down them at all but

tunning a Q is so simple
floats may be a bit harder if the demon can be adjusted from the outside
rebuild- I was doing Qs in my teens
price- kills the demon +100 points
parts- all over the place +100 points

[suville]

Q-jets may be old but in the "right hands" you cant get a more dependable reliable carb than a good ol jet. Cant argue with results so to each his own but the 500's got a SMI Q-jet! wanna race?

[70cst]

I just got my 402BB rebuilt and I am going back the the original QJet. QJet is the best...why settle for less.

[greasy68]

Demon. If one of you Qjet lovers want to trade a new road demon for a busted old Qjet we can work something out.

[Jim_PA]

Originally Posted by greasy68

Demon. If one of you Qjet lovers want to trade a new road demon for a busted old Qjet we can work something out.

I have a qjet I could get rid of. It's an APT model from the late 70's

[Big Irish]

Originally Posted by greasy68

Demon. If one of you Qjet lovers want to trade a new road demon for a busted old Qjet we can work something out.

i could probably use some parts off that Quadrajet . Some one removed the secondary linkage on mine . They say it used to be an old hotrod trick , but all it causes is the secondaries to open too fast .
Any parts like that on yours ?
Thanks

[clif1968]

Qjet

[LockDoc]

-
Read this thread....

http://67-72chevytrucks.com/vboard/s...ighlight=demon

I sent mine in and had BG work on it and it still runs rich. No more for me.....

LockDoc

[dznucks]

i have had extremely bad experience with deomn carbs. i bought one thinking it was going to solve all my aspiration problems, after all i had taken the advise of all the experts and experienced mechanics from this site. i got nothing but problems when i bought that thing. demon is a good name for them.
i sent it in and the technical support at demon could not figure out what was wrong with the carb. they spec'd it out for my motor and all. the choke never worked right, hence it would never idle on its own and when it did idle it was too high. you couldn't get the idle adjustment screws to do anything. when i frantically called the tech support guys they wanted me to drill out air bleeds and idle feed restrictors and bend linkages becasue they werent right from the factory. when i took it apart i found alot of shavings in the fuel bowls and in other fuel passages. actually not one hole in the entire body had been deburred.
i pissed me off so bad i sold it to the recyling place for scrap.
there are alot of satisfied customers out there that like them, so there has to be some good coming from them.

[Jim_PA]

Originally Posted by LockDoc

-
Read this thread....

http://67-72chevytrucks.com/vboard/s...ighlight=demon

I sent mine in and had BG work on it and it still runs rich. No more for me.....

LockDoc

LOL @ trkklr77

[HomerJ]

Mine is not the most qualified opinion here, as I have only had one Quadrajet and one pre-Demon (Barry Grant Silver Claw). Here's my experience:

Had a Quadrajet on my truck's engine when I bought it several years ago. I swapped the intake manifold for a square-bore version, which forced me into an Edlebrock 750. I eventually changed to a 600 Eddy, which helped out on the low end of the RPM range. Just a few months after the intake change, I rebuilt the whole engine, including a set of new heads, bigger cam, etc. So there, I don't have any kind of "apples-to-apples" comparison....

My Chevelle has the 820CFM Barry Grant carb on it. Lots of power once it warms up (no choke). The floats are very easy to adjust. Like some mentioned already, changing jets, drilling air bleeds, etc sucks compared to the Eddy/Quadrajet.

One thing that confuses me about the issue of complexity of the Quadrajet is how so many folks seem to hate the Quadrajet, but switch to an Eddy and love it. Based on what I have seen, the Eddy and Quadrajet are the same basic design, requiring rods/jets to be changed, then certain linkage rods to be bent to tune the carb. About the only things that I see as different are the choke pull-off and the A/C idle compensator being included. Almost all other control linkages/tuning methods seem to be the same between the two. Yes, there are definite differences, but not very many from a tuning standpoint.

From a street driveability and gas mileage point of view, I don't see how you can beat a well-tuned Quadrajet. Check out www.cliffshighperformance.com (formerly Cliffs Q Jet)

Just my two cents...
HomerJ

[Jim_PA]

Originally Posted by HomerJ
From a street driveability and gas mileage point of view, I don't see how you can beat a well-tuned Quadrajet. Check out [url

www.cliffshighperformance.com[/url] (formerly Cliffs Q Jet)

Just my two cents...
HomerJ

That book he wrote does a very good job of explaining things. I think I paid $10 at Amazon.

[Billla]

Hoooo boy. Here we go again. I'm going to make one set of posts and bolt

ANY properly sized, properly configured, properly working and properly tuned street carb will be within a few percentage points on driveability, power and fuel economy. The reason many prefer the Q-jet is it has a much wider tolerance "out of the box", but a properly tuned Edelbrock or Holley will equal or surpass it on all counts.

The Q-jet is an excellent street carb for stock to mildly modified engines if you have no plans to make ongoing tuning changes. It is not an easy carb to tune (nearly 3 decades of experience) and there is not a broad range of aftermarket parts support. For engines making over about 1HP/CID, it is not a great choice in my experience.

The Edelbrock Performer and Holley Street Avengers are highly tuneable carbs, but will almost certainly require tuning to get them right on. Add that $250 dyno tune to the price of the carb...but the payback will be a carb that is perfectly adapted to the engine. They are highly tuneable with outstanding aftermarket support.

BG had some huge quality issues out of the gate, but the last two Street Demons I've bought have been fine.

I have come to prefer the Edelbrock Performer for a street carb. VERY easy to tune, and outstanding driveability, economy and power.

[Jim_PA]

Here's a super chevy article worth checking out. They put the qjet vs 750 demon and 750 Holley. Of course engine dyno #'s aren't the world, and this is only a magazine article.... but it's interesting to note the outcome.

Edit: http://www.superchevy.com/technical/...ild/index.html

Hopefully the link will work this time.

[special-K]

I really like the Q-jet and stand by them.But,it depends on the motor.If I do a motor where a square bore air gap intake is part of the plan,then it`s a Demon.Size depends on how the motor is built.Any mis-matched carb will lose it`s benefit and perform poorly than expected...just like anything else on a motor.

[retselgerg]

fastest thing i ever rode (without NOS) had a new road demon taken off and back on went a reman'd qjet........

[92306HO5]

q-jet from jet carburators.come in 3 stages of performance.