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-   -   quad carb (https://67-72chevytrucks.com/vboard/showthread.php?t=330524)

pokethesmot 02-24-2009 06:43 PM

quad carb
 
whats the best quadra jet carb cuz i have like 6 different ones and since i gotta rebuild my carb i might as well find the best one out of my collection and rebuild it lol BTW i got all these carbs with my truck

Chlsnk 02-24-2009 07:00 PM

Re: quad carb
 
Get a holly or cheep eldelbrock its worth the money the quadra junks are exactly that. JUNK I have learned the hardway with these trying to get by on the cheep its not worth it.

Restrorob 02-24-2009 08:51 PM

Re: quad carb
 
Quote:

Originally Posted by Chlsnk (Post 3164087)
the quadra junks are exactly that. JUNK


Everyone has their own opinion as you can see in this thread;

http://67-72chevytrucks.com/vboard/s...d.php?t=330138


Poke,

Look all the carbs over. Check for wear in the throttle shafts and just over all wear and tear. Pick one that is close to the one on the truck now, Vacuum hose ports/fuel inlet etc.....

pokethesmot 02-24-2009 09:08 PM

Re: quad carb
 
Quote:

Originally Posted by Restrorob (Post 3164387)
Everyone has their own opinion as you can see in this thread;

http://67-72chevytrucks.com/vboard/s...d.php?t=330138


Poke,

Look all the carbs over. Check for wear in the throttle shafts and just over all wear and tear. Pick one that is close to the one on the truck now, Vacuum hose ports/fuel inlet etc.....

they all look purity good just a little dirty

pokethesmot 02-24-2009 09:08 PM

Re: quad carb
 
what carb gets good mpg

Restrorob 02-24-2009 09:29 PM

Re: quad carb
 
Quote:

Originally Posted by pokethesmot (Post 3164424)
they all look purity good just a little dirty

Lay them on a table, Close your eyes and spin 6 or 8 circles fast then grab one.... :lol:

Quote:

Originally Posted by pokethesmot (Post 3164427)
what carb gets good mpg


Any carb you keep your foot out of.... ;)

orbot 02-24-2009 10:34 PM

Re: quad carb
 
Quote:

Originally Posted by Restrorob (Post 3164473)
Any carb you keep your foot out of.... ;)

Specially on a V8

I had a quad on my truck got a cheap holley 600 cfm from a friend and what a difference that was 7 years ago and im a holley guy ever since

piecesparts 02-24-2009 10:37 PM

Re: quad carb
 
If you want to rebuild the Quadrajet---Make sure that it is one made by Rochester and NOT Carter. The Carter models had no brass inserts in the body where the needls pass through and they tend to erode and sluff out around the holes. This makes for a poor transition from the primaries to the secondaries. Pitch the Carter carb body.

Storm Chaser 02-25-2009 11:14 AM

Re: quad carb
 
Quote:

what carb gets good mpg
Theoretically, a Q-jet in good condition and tune wold be better on MPG if you keep your foot out of it because the primaries are so small. However, I have only seen this in reality just once- and that was with a new unit from Jet performance. Most of the Q-Jets I've seen around here are busy leaking all over themselves.

On a buddy's truck, I took his Q-jet off and put on a Motorcraft (Holley I think) 2-bbl with a plate adapter and got better mileage without too big of a loss in performance. I believe the MPG increase was due to the old carb being a swap-meet P.O.S. though.

If you're seriouse about MPG though, you might look into a TBI setup or some other form of fuel injection.

Damien 02-25-2009 12:44 PM

Re: quad carb
 
A lot of Q-jets leak because someone over tightened the bolts and warped the airhorn, body, or base. Sometimes they can be trued with a flat file. If the surfaces are too warped its junk.

You want to check the numbers on the carb to make sure it will work with your engine. All Q-jets are 750 cfm, BUT they have stops because the V6 does not need all of the flow. You don't want a carb for a 262 or V6 on your 400 or a 454 carb on your 400. They have different calibrations.

The checking for play as mentioned above is a good idea too.

You can find some very good information by doing a google search. For about $60 and probably two to three hours of your time to do the rebuild you can have a carb that works well on the street or offroad. Make sure you follow the directions that come with the carb kit and keep everything clean! Take your time setting the float.

The Q-jet has a center hung float making it less sensitive to angles. One of the Off Road magizines did a comparison a few years ago and the Q-jet beat the Holley and Edelbrock.

I have rebuild Q-jets on my trucks and they work great once you get the fine tuning done. You don't have to change the fuel lines or linkages or need adaptors to put them on either.

pokethesmot 02-25-2009 02:59 PM

Re: quad carb
 
Quote:

Originally Posted by Storm Chaser (Post 3165508)
Theoretically, a Q-jet in good condition and tune wold be better on MPG if you keep your foot out of it because the primaries are so small. However, I have only seen this in reality just once- and that was with a new unit from Jet performance. Most of the Q-Jets I've seen around here are busy leaking all over themselves.

On a buddy's truck, I took his Q-jet off and put on a Motorcraft (Holley I think) 2-bbl with a plate adapter and got better mileage without too big of a loss in performance. I believe the MPG increase was due to the old carb being a swap-meet P.O.S. though.

If you're seriouse about MPG though, you might look into a TBI setup or some other form of fuel injection.

no offense to the fuel injection users on the forum but i think id rather have my carb

dammitmitchell 02-25-2009 03:08 PM

Re: quad carb
 
hey dude save up sonme denero an get a holley =-)
that made me a happy pollock when i put mine on

willett 02-25-2009 03:26 PM

Re: quad carb
 
amen to the holleys
i threw a double pumper onto my big block a few month ago and i've no regrets

pokethesmot 02-25-2009 06:05 PM

Re: quad carb
 
well im ditching the quad cuz i just got it running and i noticed the previous owner the fuel line threats dint match up so he just taped it in there and i aint having my engine light on fire lol so i think i might go for a holley cuz they seem cheaper so whats a good holley to get

dammitmitchell 02-25-2009 08:19 PM

Re: quad carb
 
as pm'd 670
get a high rise intake and maaby a throttle spacer plate.
you'll be happy

pokethesmot 02-25-2009 09:09 PM

Re: quad carb
 
ooh man i aint got that kinda money lol does any one know a place where i could trade in like 5 q jets for a Holley or something

dammitmitchell 02-25-2009 09:14 PM

Re: quad carb
 
if youare "in good" with your napa or carquest guys..
there's a noticible amount they can take off the price for you..
mybuddy got his for 10 bucks more then a q-jet..
but.... we spend.. ahem... alot of money there..

Albatrossian 02-25-2009 10:08 PM

Re: quad carb
 
I have a Jet Performance Stage 1 780cfm on my truck and I love it. There are no bogs or stumbles and it's on and off the throttle like a lightswitch. Yes, QJets are harder to tune out of the box, but when they are, you can't find a better carb for the street. Their smaller primaries are what makes them easily adaptable to most any size engine from a 3.8 V6 to a 454. If you decide to go to a Holley, I would not go any bigger than 600cfm. You would also need a jet kit to properly tune it to your engine and a adapter plate to make it work on a stock intake since a Qjet is a spreadbore carb and Holleys are squarebore. You'll also need to modify your fuel line to make it work with the Holley and there may be some carb linkage issues to contend with.

pokethesmot 02-25-2009 10:32 PM

Re: quad carb
 
what would be the easyset/cheapist carb to hookup

Albatrossian 02-25-2009 10:33 PM

Re: quad carb
 
One of the QJets you already have.

heavychevy79 02-26-2009 12:11 AM

Re: quad carb
 
Quote:

Originally Posted by pokethesmot (Post 3166654)
what would be the easyset/cheapist carb to hookup

Edelbrock, you will have to get an adapter for either carb, but don't get an open one, get the one with four holes.

The only rebuilt Q-jet I've seen work good is from a carb repair shop.
But you can rebuild an Edelbrock with good results, I haven't used any Hollys,
and they are not popular around here either, so I can't say about them.

dammitmitchell 02-26-2009 02:13 PM

Re: quad carb
 
DO NOT GO BUY a rebuilt q-jet..
nothing but bad experiences with those..
a real big problem lately (this is from my car quest guy)
is that the vaccum secondaries just fail.. shortly after being put back in..
if you really want find a damn good carb guy and take one ot him to rebuild.. and sit down and talk to him...
ask a **** load of questions and never "pretend to know everything" just take and absorbe allll that guy has to say..
and if he likes beer.. get him some beer...
thats why i like small shops those guys will teach you everything.. and anything all because you brought them some beer..
and .. well dude.. might wanna quit "poking smot" it'll free up a **** load of money for your truck =-)

pokethesmot 02-26-2009 03:06 PM

Re: quad carb
 
Quote:

Originally Posted by dammitmitchell (Post 3167884)
DO NOT GO BUY a rebuilt q-jet..
nothing but bad experiences with those..
a real big problem lately (this is from my car quest guy)
is that the vaccum secondaries just fail.. shortly after being put back in..
if you really want find a damn good carb guy and take one ot him to rebuild.. and sit down and talk to him...
ask a **** load of questions and never "pretend to know everything" just take and absorbe allll that guy has to say..
and if he likes beer.. get him some beer...
thats why i like small shops those guys will teach you everything.. and anything all because you brought them some beer..
and .. well dude.. might wanna quit "poking smot" it'll free up a **** load of money for your truck =-)

lol ive bean clean for over a month now lol

C-10volvo 02-26-2009 03:17 PM

Re: quad carb
 
There is nothing cooler sounding that a properly tuned and jetted 795 quadrajet that's wide open.

pokethesmot 02-27-2009 09:55 AM

Re: quad carb
 
Quote:

Originally Posted by dammitmitchell (Post 3166484)
if youare "in good" with your napa or carquest guys..
there's a noticible amount they can take off the price for you..
mybuddy got his for 10 bucks more then a q-jet..
but.... we spend.. ahem... alot of money there..

our napa here doesn't even carry carbs i just called every where....man im P@ssed off. I gotta now sell my amp and stuff just to get my truck running cuz i cant find any one that wants my Q-jets...this sucks and if i cant find any one that wants my amp im just gunna have to cover the fuel leak in silicone and hope for the best


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