Hey everyone, I was just playing with my old Qjet now that its off my car, and I noticed some stuff, so lets see who can answer some dumb questions I have:

1.Is "Rochester" an independant company or is it what GM calls their in house carburetor maker? I ask because mine has a "GM" stamp on the back of it.

2. What was the c.f.m. rating of the Qjets that came on the LG-4?

3. Why is it so damned ugly? Look at a Demon carburetor, then look at a Qjet, sorta like going from Jenny McCarthy to Janet Reno huh? (not really technical, but an observation)


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---Grady---
1984 Berlinetta.
LG4 305
Holley #1850 600 c.f.m. carb.
Edelbrock Performer intake.
TH-700R4 tranny.
Flowmaster 80 series/ 3" cat-back pipe.
Accel Superstock Coil.
7.5 10-bolt rear/ 3.08's.
Edelbrock Pro-flow air cleaner.
Pioneer head unit, Pioneer front 4X6's, Cerwin Vega rear 6x9's.
Daily Driver.

Personal Quote: "The Rice-Boys all tremble with fear when the old American V8 draws near."

 

Rochester was a separate company. They also sold QJets to Ford and God knows who else. The old 428 Cobra Jet used in late 60s Mustangs came with the QJet on it stock. It's just that GM was by far their best customer for that carb.

THe carb will flow 800 CFM, but only if you modify the secondary air valve to open a full 85-90*. Stock, they're probably down in the 650-700 range.

It's not ugly, it's FUNCTIONAL. It's also a hell of a lot more compact that any Holley. OK, it's not beautiful, but it works a lot better than it looks, if you tune it right.

 

It just seems to me that if it was such a good performer youd see it on alot more performance cars than you do. Around my area, if you've got a performance SBC or BBC then youre probably running an aftermarket carburetor, Holley, Edelbrock, Carter, or Demon, usually in that order. Maybe its just me, but I just dont ever see people running a Qjet on modified engines. And also, If the Qjet ran at 650-700 cfm, why does my new Holley 600cfm seem to go through gas a little faster than the Qjet,,,,,,not that I miss it, ugly old thing,,,Ha Ha Ha

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---Grady---
1984 Berlinetta.
LG4 305
Holley #1850 600 c.f.m. carb.
Edelbrock Performer intake.
TH-700R4 tranny.
Flowmaster 80 series/ 3" cat-back pipe.
Accel Superstock Coil.
7.5 10-bolt rear/ 3.08's.
Edelbrock Pro-flow air cleaner.
Pioneer head unit, Pioneer front 4X6's, Cerwin Vega rear 6x9's.
Daily Driver.

Personal Quote: "The Rice-Boys all tremble with fear when the old American V8 draws near."

 

They're not on more high performance motors cuz most people don't know how to tune them right. People assume that all Q-jets were the same even though there were many versions, each intended for a different purpose. People put a carb that was calibrated for a completely different engine and wonder why they have problems. This is where the bad rap comes from. Also, the Q-jets get good gas mileage because of the small primaries. This is also why Q-Jet equipped Pontiac motors are such torque monsters.

 

To repeat what I just said on another thread:

"13.9 sec @ 102 mph in the quarter corrected to sea level in a 3900 lb car with 3.08 gears, starts right up every time and idles smoothly at 600 rpm in drive. Yep, q-jets sure do suck!"

Quadrajunk, huh? Okay, mine's an Edelbrock, but it's still a q-jet. Same basic design, parts interchange. Ditto to what TransAm383 said.

Ugly? In the eyes of the beholder. Personally, I think Holleys are the defination of ugly.

Oh, Rochester was a subsidiary of GM. If you worked for Rochester, you worked for GM (like Delco or Hydramatic). Yes, they sold parts to other companies, but that happened a lot more than you might think.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4. 2.93 limited slip. Cat-back from '91 GTA, ZZ3 intake, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 w/'87 LB9 block, ZZ3 cam, ported World 305 heads, Hooker headers & y-pipe, 3" Catco cat & 3" cat-back).
57 Bel Air, my 1st car. '66 396, 9.7 CR forged TRWs, Weiand Action+, Edelbrock 1901 Q-Jet, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlocks, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Idles smooth @ 600 RPM in D. Best 15.02/95.06 @ 5800' Bandimere (corrected 13.93/102.4 @ sea level).