carbon canister help
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Joined: Jun 2007
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carbon canister help
I need my 77 vette to pass inspection. It failed last weekend because the carbon canister is not connected to the engine. I have an edelbrock preformer rpm manifold and edelbrock carb. Does anywhere know if there is a port for the hose to go to on my intake setup? Any help would be greatly apreciated.
Team Owner
Joined: Jan 2006
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From: Crossville TN
If the Edelbrock carb is a Q-Jet design, just plumb it up the same way as the AIM shows. If the carb is an AFB design, just locate an available vacuum port on the carb and install the appropriate line there. The line going to the carb is for the "waste" fumes that need to be burned by the engine.
Melting Slicks
Joined: Jun 2005
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From: Arkansas
Advanced
Joined: Apr 2006
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From: Finly IN
For additional info Check out PVC thread
Info from LARS, thinpockets and PCV thread
Originally Posted by morganjd
LARS,
On this same subject, from the charcoal cannister comes two lines, one goes to the pcv valve and then continues to the base of the carb, this is the large hose, the second line goes from the canister to directly to the carb and is the small hose. My question is should the small hose go to a ported vacuum sorce or a full time vacuum source? I am using a holley carb on the 71 LS6?
Yes, the charcoal canister vent line goes to ported vacuum. By doing this, you avoid what effectively becomes a massive vacuum leak at idle: The ported source does not pull any (or much) vacuum at idle, so you do not get any adverse intake charge dilution at low engine speed. Once the engine is off idle and operating at higher rpm, the ported source will allow venting of the canister with a slight dilution of the intake charge. This dilution becomes irrelevant at the higher rpm. Under power, since there is no manifold vacuum at WOT, the system does not function, so there is no WOT power penalty. So overall, it's really not a bad system, and it does not rob any power or drivability from the engine.
There is a diagram inserted halfway through the thread.
Originally Posted by morganjd
LARS,
On this same subject, from the charcoal cannister comes two lines, one goes to the pcv valve and then continues to the base of the carb, this is the large hose, the second line goes from the canister to directly to the carb and is the small hose. My question is should the small hose go to a ported vacuum sorce or a full time vacuum source? I am using a holley carb on the 71 LS6?
Yes, the charcoal canister vent line goes to ported vacuum. By doing this, you avoid what effectively becomes a massive vacuum leak at idle: The ported source does not pull any (or much) vacuum at idle, so you do not get any adverse intake charge dilution at low engine speed. Once the engine is off idle and operating at higher rpm, the ported source will allow venting of the canister with a slight dilution of the intake charge. This dilution becomes irrelevant at the higher rpm. Under power, since there is no manifold vacuum at WOT, the system does not function, so there is no WOT power penalty. So overall, it's really not a bad system, and it does not rob any power or drivability from the engine.
There is a diagram inserted halfway through the thread.
