Fuel & Emissions Hard Lines '72 A-body
#1
Fuel & Emissions Hard Lines '72 A-body
I have a question about the emissions hard line that runs along the frame rail from the stand pipe (behind the rear seat) to the charcoal canister in the engine compartment. My car had only 2 hard lines running along the passenger side frame rail: a 3/8" fuel supply line and a 5/16" emissions vapor line. Both were badly rusted. When I ordered new lines, I mistakenly ordered a 1/4" fuel return line instead of the 5/16" emissions line. Would there be any issues with using the 1/4" line for the emission circuit or could this cause a restriction? It's only used for fuel vapors so using the 1/4" line might not be a problem and I'm not concerned with modifying the tubing.
Here's a pic:
The 1/4" hard line has the yellow cap, it needs to connect to the 5/16" line indicated by the red arrow.
Here's a pic:
The 1/4" hard line has the yellow cap, it needs to connect to the 5/16" line indicated by the red arrow.
#6
Came up with another question about the vapor canister & emissions plumbing. The canister connected to the carburetor with a 1/4" vacuum hose. Was the port on the carb at manifold vacuum or was it a timed or ported vacuum port? I will be plumbing the canister to a FiTech EFI throttle body and not sure of the best place to connect. Thanks.
Rodney
Rodney
#7
Came up with another question about the vapor canister & emissions plumbing. The canister connected to the carburetor with a 1/4" vacuum hose. Was the port on the carb at manifold vacuum or was it a timed or ported vacuum port? I will be plumbing the canister to a FiTech EFI throttle body and not sure of the best place to connect. Thanks.
Rodney
Rodney
My current plan (not fully thought out, let alone tested) is to drill a hole, probably in the 0.060 to 0.080 range, in a plug and stuff that in the vacuum hose. I need to measure the hole in the qjet base plate....... Remind me - I've got one on the shelf, just need to actually do it.
The canister has little to no restriction, so it'll pass as much air as you please. Hence really don't want a wide open fitting.
#8
The stock 7042250 base plate has two holes for the canister purge, each approximately 0.050", located above the primary throttle blades. My "precision gauges" (aka drill bits) have a gap from 0.046 to 0.052, and the hole is difficult to get to without fully disassembling the base plate, so I'll say 0.050 +- 0.005.
#9
Oddball:
I'll be using a FITech EFI system. The throttle body has two 3/16" ports; one is timed (ported) and the other is full vacuum. I can use the full vacuum port for the distributor vacuum advance and the timed port for the vapor emission canister. Do you think the timed 3/16" port would cause a lean condition off-idle or should I plan to put a restriction in the 3/16" vacuum line as you suggested?
I'll be using a FITech EFI system. The throttle body has two 3/16" ports; one is timed (ported) and the other is full vacuum. I can use the full vacuum port for the distributor vacuum advance and the timed port for the vapor emission canister. Do you think the timed 3/16" port would cause a lean condition off-idle or should I plan to put a restriction in the 3/16" vacuum line as you suggested?
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Oldssupreme
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January 19th, 2016 05:17 PM