Carbed LS1--possible to keep CCqjet?

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Nov 16, 2010 | 05:39 PM
  #1  
Hey guys,

I was just curious about this. I know swapping in an LS1 into our cars is very popular and with some of the new ignition items out there that allow you to swap carbs onto them, I was curious if anyone has done it and has kept their original CCQjet? I'm also curious because I think I would like to do this swap eventually, most likely 2+ years down the road if I can find an LS1 (or LS2, LS7 etc) on the cheap.
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Nov 17, 2010 | 03:17 PM
  #2  
Re: Carbed LS1--possible to keep CCqjet?
Why spend all that money on an LSx swap then keep the stock Qjet?
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Nov 17, 2010 | 03:18 PM
  #3  
Re: Carbed LS1--possible to keep CCqjet?
i dont believe anyone has a spreadbore manifold for these cars and the computer setup for the qjets would be a gigantic step back. any particular reason why you're contemplating this? it won't be cheaper than current options out there and you've still gotta figure out how to set up a distributor to be controlled by the ancient engine computer.

really best to stick with the tried and true on these engines - stock fuel setup or edelbrock/msd + aftermarket carb
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Nov 17, 2010 | 04:51 PM
  #4  
Re: Carbed LS1--possible to keep CCqjet?
Quote: Why spend all that money on an LSx swap then keep the stock Qjet?
Couple of reasons, one of which is I firmyly believe the Qjet is superior to any Holley or Edelbrock. Second, my Qjet has already been rebuilt to support a 400hp 355 thats in my T/A now. The other primary reason is to pass inspection (back home is visual so I need smog pump and AIR tubes etc.) I know that people have installed carbs on LSX motors and have them run fine, so I was thinking it may be easier to keep my stock computer, fuel pump, fuel lines etc. And mae that work than buying all new stuff and ripping out the old.
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Nov 17, 2010 | 06:26 PM
  #5  
Re: Carbed LS1--possible to keep CCqjet?
Quote: Couple of reasons, one of which is I firmyly believe the Qjet is superior to any Holley or Edelbrock. Second, my Qjet has already been rebuilt to support a 400hp 355 thats in my T/A now. The other primary reason is to pass inspection (back home is visual so I need smog pump and AIR tubes etc.) I know that people have installed carbs on LSX motors and have them run fine, so I was thinking it may be easier to keep my stock computer, fuel pump, fuel lines etc. And mae that work than buying all new stuff and ripping out the old.
You have a CCqjet that puts out 400hp?
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Nov 17, 2010 | 06:34 PM
  #6  
Re: Carbed LS1--possible to keep CCqjet?
it can be done. with an adapter. yes qjets can handle 400hp easily. make sure you get a big cowl hood.
i suppose it is not an electric qjet either.

http://www.edelbrock.com/automotive_..._spacers.shtml
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Nov 17, 2010 | 07:03 PM
  #7  
Re: Carbed LS1--possible to keep CCqjet?
Quote:
Couple of reasons, one of which is I firmyly believe the Qjet is superior to any Holley or Edelbrock. Second, my Qjet has already been rebuilt to support a 400hp 355 thats in my T/A now. The other primary reason is to pass inspection (back home is visual so I need smog pump and AIR tubes etc.) I know that people have installed carbs on LSX motors and have them run fine, so I was thinking it may be easier to keep my stock computer, fuel pump, fuel lines etc. And mae that work than buying all new stuff and ripping out the old.
Sounds like a cali swap and you wouldnt be able to use a carb on a LSx anyways. When doing and emissions friendly swap the swap must meet the emissions standards of the new engine and since none of the LSx engines came with them youd automatically fail visual
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Nov 17, 2010 | 07:47 PM
  #8  
I maintain that the cheapest LSx is a complete dropout, which will include all the induction, harnesses, PCM, transmission, etc. You would have to spend more to get a CC q-jet adapted to the engine, and you would not have as good of a system.

I personally haven't heard of anyone trying it. The carb LSx swaps that are done are using an aftermarket box that uses the LSx coils, cam & crank sensors, etc. And, they are all squarebore carbs. I suppose you could figure out a way to tell the PCM to pulse the MCS and use the TPS signal from the carb, but, wow, what a science project!

Plus, the carb'd LSx systems require a cowl hood. EFI doesn't.
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Nov 18, 2010 | 07:54 AM
  #9  
Re: Carbed LS1--possible to keep CCqjet?
Quite frankly, by the time you've invested the money that you will no doubt have to invest to get that CCQuadratoilet carb to work well with an LSx motor you would've easily been able to keep the injection system that came on the motor, which is far superior to the carb anyway.

I'm not so great at sugar coating stuff as you can see. My advise: Dump the carb, use a full drop-out and never look back!
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Nov 18, 2010 | 08:12 AM
  #10  
Quote: I'm not so great at sugar coating stuff as you can see. My advise: Dump the carb, use a full drop-out and never look back!
Doc says I need to reduce carbs. So, I'm 100% EFI now...

(Except I'm still moderating the Carburetor forum...)
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Nov 18, 2010 | 08:22 AM
  #11  
Re: Carbed LS1--possible to keep CCqjet?
Quote: I maintain that the cheapest LSx is a complete dropout, which will include all the induction, harnesses, PCM, transmission, etc. You would have to spend more to get a CC q-jet adapted to the engine, and you would not have as good of a system.

I personally haven't heard of anyone trying it. The carb LSx swaps that are done are using an aftermarket box that uses the LSx coils, cam & crank sensors, etc. And, they are all squarebore carbs. I suppose you could figure out a way to tell the PCM to pulse the MCS and use the TPS signal from the carb, but, wow, what a science project!

Plus, the carb'd LSx systems require a cowl hood. EFI doesn't.
So the question then is, will my factory fuel lines that were originally made for a carb handle the pressure that an EFI system runs at or would I have to run new fuel lines from a later model fuel injected car?
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Nov 18, 2010 | 08:26 AM
  #12  
Re: Carbed LS1--possible to keep CCqjet?
the issue you have with the lines is that they're all clamped; you could have the ends flared to accept fittings and go that route, but the rubber that's in place now is not sufficient for the pressure of the FI setup. However, still a small drop money-wise compared to the rest of the swap (running into this issue myself right now on my 87)
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Nov 18, 2010 | 08:29 AM
  #13  
Re: Carbed LS1--possible to keep CCqjet?
Quote: Doc says I need to reduce carbs. So, I'm 100% EFI now...
OMG, that comment made my day. That just became my facebook status.
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Nov 18, 2010 | 11:23 AM
  #14  
Re: Carbed LS1--possible to keep CCqjet?
Quote:
(Except I'm still moderating the Carburetor forum...)
Not everyones perfect

Quote:
So the question then is, will my factory fuel lines that were originally made for a carb handle the pressure that an EFI system runs at or would I have to run new fuel lines from a later model fuel injected car?
People do it all the time but it is dangerous. Easiest upgrade for a solid fuel system is using a 3rd gen EFI sender in the tank (threaded fittings) and AN6 lines up to the rails. PNs are posted for the C5 regulator in the stock location
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Nov 18, 2010 | 01:33 PM
  #15  
Re: Carbed LS1--possible to keep CCqjet?
Quote: Not everyones perfect



People do it all the time but it is dangerous. Easiest upgrade for a solid fuel system is using a 3rd gen EFI sender in the tank (threaded fittings) and AN6 lines up to the rails. PNs are posted for the C5 regulator in the stock location
Braided lines from the fuel tank all the way up would be...expensive.
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Nov 18, 2010 | 02:09 PM
  #16  
Re: Carbed LS1--possible to keep CCqjet?
About $300 with the pump
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Nov 18, 2010 | 02:38 PM
  #17  
Ozz, I know you've been trying to work through CC carb issues. Why do you want to perpetuate the pain? (Said never having had CC carb problems myself.)

As for the carb fuel lines and EFI, not saying my way is the only way, but here's what I did for the LS1/4L60E: EFI pick-up (from TGO member), EFI repair line from Advance Auto (part high pressure braided rubber, part seamless steel tube), bent and flared to a Russell fitting to a Vette LS1 filter. Return line using new clamped rubber (low pressure). Line to engine compartment bent to come up behind the steering shaft, flared to accept Russell fitting. Line in engine compartment flared to accept brass fitting to adapt to an LQ4 line, that was cut and a compression fitting attached to the flared line. Done.

The metal lines handle the pressure with no problem. Any stock carb rubber in the supply side needs to be replaced with high pressure stuff.

Oh, my factory lines were factory V6, so they went up to the driver side of the engine compartment. On V8's, it goes to the passenger side, so you can either bend it up and reverse the fuel rail to connect it on that side, or run all new line up the driver side (which is what I did on the LS1/T56, which was a factory V8 car).
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Nov 18, 2010 | 03:00 PM
  #18  
Re: Carbed LS1--possible to keep CCqjet?
Quote: Oh, my factory lines were factory V6, so they went up to the driver side of the engine compartment. On V8's, it goes to the passenger side, so you can either bend it up and reverse the fuel rail to connect it on that side, or run all new line up the driver side (which is what I did on the LS1/T56, which was a factory V8 car).
sure about that? the factory V8 FI lines should be coming up on the driver side, where as the carbed V8's come in on the passenger. something I just ran into on my 87 TA and 89 RS.

OP, if you don't want to do braided from front to back, you can just reuse the metal lines that are in place and just deal with buying a few more adapters to get everything attached up
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Nov 18, 2010 | 06:14 PM
  #19  
Re: Carbed LS1--possible to keep CCqjet?
Since the topic was CC carb, I was speaking of factory carb'd V8 cars.

Yes, EFI is on the driver side.
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Nov 18, 2010 | 09:02 PM
  #20  
Re: Carbed LS1--possible to keep CCqjet?
Quote: Ozz, I know you've been trying to work through CC carb issues. Why do you want to perpetuate the pain? (Said never having had CC carb problems myself.)
Maybe I'm just a glutton for punishment? I've finally got mine running mostly well now, just need to fine tune it, been working with NAF on that.

The main reason is that...for as stupid as it sounds, I want the car to "look" factory for it's year...which means a carb, ac hooked up, smog pump, air lines etc. So I figured I'd look into seeing how much of a pain it would be to make it work with the factory CC carb before going EFI or doing something along those lines which would also mean I would want to be putting in the ECM from whatever donor car I take the motor from and whatever else I need to swap.
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