Jet Performance Quadrajet JET Performance anyone gotz?

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JD Miller

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I have Carb rebuild parts from Cliff Ruggles , But havent had time to finish building a core I have. To frickin busy with many other projects, been sitting for over a year

Is anyone running a JET Performance Rochester Quadrajet.
STAGE 1 - Disassembled, cleaned and inspected to restore factory stock performance. Casting plugs are sealed with epoxy to prevent leak-down. All of the circuits are checked for proper sizing and the calibration is checked for proper jets, primary metering rods and secondary metering rods. Quadrajet Carb is reassembled with new float, choke pull-off and bronze bushed throttle shafts.
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STAGE 2 - All features of Stage 1 carbs plus fully recalibrated idle, off idle, main, accelerator pump and high speed circuits. Provides improved idle quality, instant throttle response and maximum torque and hp.

Have you had good luck or issues?
 
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3 Ton

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ALL carbs are made in China and they have a very limited life span, on purpose.

Go get a 4000 series real AFB
 

Ricko1966

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The jet performance Qjets are remans using Qjet core. Are they any good? IDK
 

77Dmax

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As a guy who has worked many q-jets, I would strongly suggest not buying one that hasn't been tailored to your engine.
 

JD Miller

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As a guy who has worked many q-jets, I would strongly suggest not buying one that hasn't been tailored to your engine.
If you knew what you were talking about, You'd know you can get one that is "tailored to your engine". And they are modified with adjustable power piston for further adjustment

Maybe you should get Cliff Ruggle's book and do some studying
 

JD Miller

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Next someone will say to buy fuel injection and a computer ECM :emotions34: :insane:
Please close the thread :buttkick::disgust::emotions34:
 
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nvrenuf

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I’m no real help but I thought I’d post that my qjet was built by Sean Murphy Induction which was supposed to be a group of former Jet employees, SMI closed a couple of years ago.

That said, I sent my core to SMI and requested a Stage 2 rebuild. I had to fill out a questionnaire detailing my engine and truck so it was built to spec for my application. I’m happy with it and it runs really good, I only needed to make the typical minor adjustments when I installed it.
 

77Dmax

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If you knew what you were talking about, You'd know you can get one that is "tailored to your engine". And they are modified with adjustable power piston for further adjustment

Maybe you should get Cliff Ruggle's book and do some studying

You must be registered for see images attach
 

77 K20

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I bought and ran a JET 35002 stage 2 carb that I bought back in 2014. I ran it for a few months and it did well on the street but wasn't good for going up or down extreme hills nor at slow climbing at 10,000'+ So I removed it and went to fuel injection that happened to be better suited for how I was using my truck.
 

ali_c20

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35% off because of black week at Jet carbs. Do a close visual inspection and if everything looks good give it a try.
 

arborvitian

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JD Miller

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I'm running a Stage 1 (36001) on my truck, and the jury is still out. That's why I got on here, actually. I'm going to ask for help tweaking things. My engine is totally stock with 118,000 miles on it, so I was looking for a factory tune on the carb.

The one I got was built on a newer core than the one my truck had, but it's a real Rochester Quadrajet, and they did a beautiful job with it. Here's my stock 50 year old q-jet vs. the Stage 1:

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I didn't think to check the numbers on it while it was off, and I'm not interested in going outside in sub zero temps to take it off and look at the numbers. My original carb was a '75 model, and my truck is a '74, so I'm thinking my truck was built late in '74, and my carb is original.

My truck isn't running quite right since I installed the Stage 1 (and plugs and wires, cap, rotor, points, and set the timing), but it's running a LOT better than it did. When I drove it home, I didn't go up that steep of a hill, and I had to downshift all the way to 1st to keep it from stalling out. Now, I'm having weird problems. It seems to be getting stuck on the fast idle cam. It bogs down sometimes. I'm only getting 6 mpg out of the truck. I'm not sure how much is the carburetor, and how much is other stuff. I don't have any vacuum leaks. No, seriously, no vacuum leaks. I think my mechanical advance in my distributor is out of whack, and that's the next thing I intend to replace. My initial timing is 12°, and my idle is set to 900 (factory spec), but my real world idle is anywhere from 800 to 2100, and it often acts like the throttle cable is stuck, even though it most definitely is not stuck. It bogs on acceleration sometimes, and sometimes it scoots like a scalded dog. It's unpredictable. I had at least one backfire through the carb while revving it up at idle, so that ain't good.

I don't know, man. I'm still working through this stuff. It's better than my original carb, but would I be better off rebuilding my original carb? Maybe. I'm thinking about trying that too.

Here is a post from Cliff Ruggles about Jet Perf Carbs (for what its worth... He could be a little bias too )

.https://forums.maxperformanceinc.com/forums/showthread.php?t=847179

I have LOTS of experience with them. They are sent here ALL THE TIME because they don't work for chit!

Coincidentally I have one on the bench as I type this purchased for a 455 project that only made one pull on owners new engine on the dyno.

It's built from a 1979 Oldsmobile core and no kidding the jets are marked "77" but a .080" drill bit passes right thru them!

I actually love those carbs, all nicely plated and recolored castings. I just have to "gut" them, throw everything out, and set them up with much better parts exactly for the application.

That work is so good and easy I quit doing restorations completely and not missing any of that "bottom of the farm pond" stuff at all......FWIW.....
He does like nicely plated and recolored castings.:cool:

Just gives me pause about blowing $500 for a Jet Perf Carb.
:cool:


Arborvitian, Keep us posted on getting you truck running good with that Jet Qjet. Hope you get it running good :waytogo: .

.
 
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Drap

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My Qjet acted similarly. The power valve was stuck open. Don't know why. Don't recall of any backfires or similar events, but it was stuck. If yours was set too high or wrongly jetted, might expect similar results
 

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