Author Topic: Can someone please explain something to me  (Read 10984 times)

Offline Maintenanceman

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Can someone please explain something to me
« on: February 20, 2009, 08:31:40 pm »
Im changing my carb and intake set up and I stumbled across a component that I wasnt sure what it was. If you look down beside the radiator on the drivers side, theres a coffe can size canister down there. It has a vacuum line that ran to my qaudrajet but the new edelbrock doesnt have a vacuum port for it. I thought it was something to do with the EGR or emissions components. Is this correct? Do I actually need this thing to run? By the way all of the EGR components that were on my truck (werent hooked up) but are now gone. Sorry I dont have any pictures of the part I was looking at but Im at work and was just curious.
Truck info is in sig.

TIA,
Ben
1985 Silverado K20- 355 SBC Vortec heads and a lil' cam...

Offline joesgarage71

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Re: Can someone please explain something to me
« Reply #1 on: February 20, 2009, 08:51:00 pm »
Fuel tank vacuum canister. It draws fuel tank vapors into the carb. It will run with out it.
« Last Edit: February 20, 2009, 08:54:11 pm by joesgarage71 »
78' K-20 355/SM465/twin stick 205 6" on 36's
14 bolt FF/big bearing Dana 44 4.56 gears

92' GMC C-1500 454/4L80E/14 bolt

Offline Maintenanceman

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Re: Can someone please explain something to me
« Reply #2 on: February 20, 2009, 08:52:11 pm »
Is it a neccesity?
1985 Silverado K20- 355 SBC Vortec heads and a lil' cam...

Offline joesgarage71

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Re: Can someone please explain something to me
« Reply #3 on: February 20, 2009, 08:57:21 pm »
I'd leave it on.
78' K-20 355/SM465/twin stick 205 6" on 36's
14 bolt FF/big bearing Dana 44 4.56 gears

92' GMC C-1500 454/4L80E/14 bolt

Offline Maintenanceman

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Re: Can someone please explain something to me
« Reply #4 on: February 20, 2009, 08:58:07 pm »
So can I just tie it into a vacuum line somewhere?
1985 Silverado K20- 355 SBC Vortec heads and a lil' cam...

Offline joesgarage71

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Re: Can someone please explain something to me
« Reply #5 on: February 20, 2009, 09:03:06 pm »
 There should be a diagram on the top of the core support, it will tell you how to route the vacuum lines.
78' K-20 355/SM465/twin stick 205 6" on 36's
14 bolt FF/big bearing Dana 44 4.56 gears

92' GMC C-1500 454/4L80E/14 bolt

Offline Maintenanceman

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Re: Can someone please explain something to me
« Reply #6 on: February 20, 2009, 09:04:40 pm »
What exactly does the cannister do?
1985 Silverado K20- 355 SBC Vortec heads and a lil' cam...

Offline joesgarage71

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Re: Can someone please explain something to me
« Reply #7 on: February 20, 2009, 09:07:53 pm »
It directs the gas fumes into the carb to be used. Instead of letting them into the atmosphere.
78' K-20 355/SM465/twin stick 205 6" on 36's
14 bolt FF/big bearing Dana 44 4.56 gears

92' GMC C-1500 454/4L80E/14 bolt

Offline eventhorizon66

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Re: Can someone please explain something to me
« Reply #8 on: February 21, 2009, 12:24:51 am »
On my '85 there was also a line that pulled excess vapors from the carb fuel bowl.  I now have an Edelbrock carb as well and it doesn't have any accommodations for such a line so I have it plugged at the vapor canister.  I'll post pics of how I have mine hooked up tomorrow if you like.
'85 C10 SWB 350 700R4 TKO600

Offline VileZambonie

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Re: Can someone please explain something to me
« Reply #9 on: February 21, 2009, 09:09:10 am »
Hook it to the breather inlet of your air cleaner. Do not hook it to a vacuum source.
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline Maintenanceman

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Re: Can someone please explain something to me
« Reply #10 on: February 21, 2009, 09:45:50 am »
Thanks guys thats I was looking for.
1985 Silverado K20- 355 SBC Vortec heads and a lil' cam...

Offline VileZambonie

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Re: Can someone please explain something to me
« Reply #11 on: February 21, 2009, 09:50:31 am »
What kind of air cleaner do you have?
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              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline 78 Chevyrado

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Re: Can someone please explain something to me
« Reply #12 on: February 21, 2009, 10:02:26 am »
my motor book shows that since you have removed everything else, one line goes to the tank, and the line to the engine goes to the port vaccum line.  its the port on the front of the edelbrock that pulls NO vaccum at idle.  There should be a thermostatic switch in between the canister and the carb.  Stock, one line went to the carb to the ported vaccum port, and one line tied in with the pcv hose or went to the egr valve.
« Last Edit: February 21, 2009, 10:16:58 am by 78 Chevyrado »
Kenny

1978 C-20, 350/400, 3.73, Graystone Metallic, Raceline Renegade 8 Wheels - 18x8.5, 275/70R18 BFG KO's

Offline eventhorizon66

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Re: Can someone please explain something to me
« Reply #13 on: February 21, 2009, 12:18:50 pm »
Hook it to the breather inlet of your air cleaner. Do not hook it to a vacuum source.

What do you mean?  On mine there is a breather line (that goes to air cleaner), a inlet line (from gas tanks), a purge valve line (to thermostatic valve, then ported vacuum source), and a purge line (to full vacuum, tee'd in with PCV).  This isn't right?
'85 C10 SWB 350 700R4 TKO600

Offline Maintenanceman

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Re: Can someone please explain something to me
« Reply #14 on: February 21, 2009, 06:54:27 pm »
I have an Edelbrock Intake that I bought at autozone. There is no place to hook it into.
1985 Silverado K20- 355 SBC Vortec heads and a lil' cam...