Cliff's Quadrajet Parts and Rebuild Kits

General Category => Quadrajet Carb Talk and Tips => Topic started by: Ethan1 on June 22, 2013, 04:54:18 PM

Title: Odd Carburetor
Post by: Ethan1 on June 22, 2013, 04:54:18 PM
 I have a Rochester DualJet 2MC #17056156 carb. Can anyone tell me how the secondary system works? Or is there even a secondary system? The secondary flaps in the air horn are non-existent, but still has the secondary flaps in the throttle body. It looks like a Quadrajet, except for the air horn assembly w/ no secondary flaps. Carb kind of confuses me. :o Thanks!
Title: Re: Odd Carburetor
Post by: Ethan1 on June 23, 2013, 03:39:34 PM
I have a Rochester DualJet 2MC #17056156 carb. Can anyone tell me how the secondary system works? Or is there even a secondary system? The secondary flaps in the air horn are non-existent, but still has the secondary flaps in the throttle body. It looks like a Quadrajet, except for the air horn assembly w/ no secondary flaps. Carb kind of confuses me. :o Thanks!

 Here is what mine looks like:

 (http://i.ebayimg.com/t/United-Remanufacturing-1-277-Rochester-2MC-2-Bbl-Hot-Air-Non-Electric-Choke-/00/s/NDAwWDQwMA==/z/aaMAAMXQO21RqH8x/$(KGrHqF,!ncFBZ)1W1VtBRqH8)ZB5Q~~60_12.JPG)
Title: Re: Odd Carburetor
Post by: Shark Racer on June 23, 2013, 04:15:56 PM
Fascinating. Without the air valves, I can't imagine that it really has secondaries, but it still requires a 4 barrel intake to run. Maybe something they did to try to simplify costs? (1 intake for all cars?)

Have you taken it apart to see if there's any passages? Would love to see photos of a detailed teardown.
Title: Re: Odd Carburetor
Post by: Ethan1 on June 23, 2013, 07:09:03 PM
Fascinating. Without the air valves, I can't imagine that it really has secondaries, but it still requires a 4 barrel intake to run. Maybe something they did to try to simplify costs? (1 intake for all cars?)

Have you taken it apart to see if there's any passages? Would love to see photos of a detailed teardown.

 Haven't taken it apart yet, Steve. Will do a detailed teardown of this carb though. :)
Title: Re: Odd Carburetor
Post by: Shark Racer on June 24, 2013, 12:22:50 AM
Looking forward to it. Thanks Ethan!
Title: Re: Odd Carburetor
Post by: omaha on June 24, 2013, 11:35:45 PM
yeah its just the front half of a Q-jet but with the casting still in place. they also made them without the rear so it looks like an actual 2  barrel. I guess if you were real careful you could make it into a 4 barrel. don't know if the passages ae there though.
Title: Re: Odd Carburetor
Post by: Ethan1 on June 25, 2013, 08:55:04 AM
 Mine is a DualJet 165.

 Have way down the page it shows the model DualJet 165.

 http://www.hotrodders.com/forum/would-stock-holley-good-mpg-189464.html
Title: Re: Odd Carburetor
Post by: Shark Racer on June 25, 2013, 06:07:18 PM
Great info, thanks Ethan. :)
Title: Re: Odd Carburetor
Post by: Schurkey on July 06, 2013, 12:09:06 PM
There may be a functioning Q-Jet throttle body, but the carb is just a two-barrel.  Just making a guess:  If you've got throttle plates for the secondaries, someone replaced the throttle body with one from a Q-Jet.  I would not expect GM to have paid for the throttle plates, throttle shaft, and machining/assembly to put non-usable secondary throttle plates into a carb that isn't going to have functioning secondaries.

DualJet 165
(http://hbassociates.us/DualJet165Top.jpg)

DualJet 200
(http://hbassociates.us/DualJet200Top.jpg)

(http://hbassociates.us/DualJet200bottom.jpg)

DualJet 210
(http://hbassociates.us/DualJet210top.jpg)

(http://hbassociates.us/DualJet210Bottom.jpg)
Title: Re: Odd Carburetor
Post by: Ethan1 on July 06, 2013, 03:14:09 PM
There may be a functioning Q-Jet throttle body, but the carb is just a two-barrel.  Just making a guess:  If you've got throttle plates for the secondaries, someone replaced the throttle body with one from a Q-Jet.  I would not expect GM to have paid for the throttle plates, throttle shaft, and machining/assembly to put non-usable secondary throttle plates into a carb that isn't going to have functioning secondaries.

DualJet 165
(http://hbassociates.us/DualJet165Top.jpg)

DualJet 200
(http://hbassociates.us/DualJet200Top.jpg)

(http://hbassociates.us/DualJet200bottom.jpg)

DualJet 210
(http://hbassociates.us/DualJet210top.jpg)

(http://hbassociates.us/DualJet210Bottom.jpg)

 You are correct, Schurkey. Thought it had secondary throttle plates. I must of had a brain fart. :o Here are some pictures of it.

 (http://i144.photobucket.com/albums/r184/Ethan1849/IMG_0149_zpsfb1d3a2e.jpg)

 (http://i144.photobucket.com/albums/r184/Ethan1849/IMG_0150_zps0522b4ac.jpg)

 (http://i144.photobucket.com/albums/r184/Ethan1849/IMG_0151_zpsdfda6dae.jpg)
Title: Re: Odd Carburetor
Post by: PMD1969 on July 16, 2013, 07:56:35 AM
Could have been a cheap way of trying to save on fuel.  Instead of changing manifolds, linkage, vac lines and everything else on the car/motor this carb would step it down to a two barrel.
Title: Re: Odd Carburetor
Post by: Shark Racer on July 16, 2013, 10:03:44 AM
I'm thinking it was to ease up production. One manifold for everything. I'd love to own one, neat carb.
Title: Re: Odd Carburetor
Post by: Ethan1 on July 16, 2013, 04:01:04 PM
I'm thinking it was to ease up production. One manifold for everything. I'd love to own one, neat carb.

 It is a neat carb. Unusual, but neat. ;D