Dual Jet Rochester circa 1977 why?? - Hot Rod Forum : Hotrodders Bulletin Board
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Old 09-02-2009, 09:53 AM
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Dual Jet Rochester circa 1977 why??

Why did GM come out with the venerable Dual Jet Rochester back in 1977..??
Carb is numbered 17057172 and what vehicles did it come out on other than the Poncho?? Was it a good unit??
Thanks!!

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Old 09-02-2009, 10:40 AM
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Quote:
Originally Posted by opelitis5
Why did GM come out with the venerable Dual Jet Rochester back in 1977..??
Carb is numbered 17057172 and what vehicles did it come out on other than the Poncho?? Was it a good unit??
Thanks!!
Venerable? I would call the 2GC venerable. I call the Dual Jet a paperweight.

Why did they come out with it? because the Qjet was already in production. The original DJ was actually a full Qjet body with the secondaries blanked off. It was first used on the unlamented Olds 260 V8 in the mid-1970s. Later versions of the DJ had the casting trimmed to just the primary side. The advantage of the original design was that it bolted to any Qjet intake. The newer version required a dedicated 2bbl intake, but when the CCC system came out in the early 1980s, the Qjet hardware (which only operated on the primary side anyway) was able to be applied to the DJ as well. Fewer different designs means lower production costs. The Buick V6s in the early 1980s got the CCC Dual Jets - at least they did until the SFI system came into widespread use.
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Old 09-02-2009, 10:46 AM
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Thanks Joe!! Exactly what I was after..
T.
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Old 09-02-2009, 09:45 PM
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Dualjet is a great carb if you don't need the flow of the 4-bbl. Its the primary side of the Qjet, which IMO is one of the greatest carbs ever invented.

I wouldn't call it venerable. Brilliant, accurate, and reliable... but not venerable.

Why did they invent it? Because the flow that they can provide is more than enough for the mild, smogger, low-po engines from the 70s. The engine only ingests the flow it needs. If you put two 4-bbl carbs on a 265, it won't make any more power. If you can supply the engine's needs with a 2bbl, why not use one?
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Old 09-03-2009, 05:06 AM
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Listen to this: We used to tow a rear engine dragster in an enclosed trailer with a 77 Suburban and all the tools and spare parts with a 454ci using the ol DualJet.. Frigging thing used to haul ***** late at night going home after a full day of drags at 80 to 85 miles an hour I kid you not.. Driver used to scare the heck out of us with a weird smile on his puss and foot to the boards.. Carb never missed a beat. Twas the DualJet, me hearties.. Lucky we still around to talk about the ole days, eh??
Take care!!
T.
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Old 09-03-2009, 04:16 PM
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i dont have any problem with the dual jets either, run great if in good condition, just like most any other carbs,

i like them. and save any i ever come across but rare nowadays at least here anyways.

havent seen one in several years now.
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Old 09-03-2009, 05:33 PM
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Quote:
Originally Posted by opelitis5
a 454ci using the ol DualJet
The hard part is finding a 2-bbl intake for a BBC. Only one I know of came on a 396 station wagon. Could always use one of those fine 4 to 2-bbl adapters, I suppose.
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Old 09-04-2009, 08:41 AM
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Quote:
Originally Posted by cobalt327
The hard part is finding a 2-bbl intake for a BBC. Only one I know of came on a 396 station wagon. Could always use one of those fine 4 to 2-bbl adapters, I suppose.
Well, if you want to run a Dual Jet, get one of the early ones that is a full Qjet body with the secondaries blanked. That bolts to any Qjet manifold.

Or, you could just remove the secondary link on any Qjet...
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