PCV question
Thread Starter
Instructor
Joined: Jan 2007
Posts: 126
Likes: 0
From: Southern, Ontario
PCV question
My 65 327/300 has an edelbrock 1806 carb with performer RPM intake and mild edlebrock cam.
I'm adding a insulator gasket approx .320 thick to help with heat soak starting problems. To get more hood clearance I'm adding a drop down style base air cleaner.
I noticed that the previous owner has engineered the PCV sytem with a hoses coming out of the valve covers (LT1) style. One hose with pvc valve from the driver side valve cover attached to air cleaner base and the other is attached to pass. side valve cover and is connected to the power brake port ???? I don't have power brakes. Should this port plugged ?? My distributor is plugged into timed vacuum port and manifold port is not being used.
The pcv port at the front of the carb is capped, not being used. I have low vacuum 7" Could this be my low vacuum problem ??
Please advise. Thanks, Peter
I'm adding a insulator gasket approx .320 thick to help with heat soak starting problems. To get more hood clearance I'm adding a drop down style base air cleaner.
I noticed that the previous owner has engineered the PCV sytem with a hoses coming out of the valve covers (LT1) style. One hose with pvc valve from the driver side valve cover attached to air cleaner base and the other is attached to pass. side valve cover and is connected to the power brake port ???? I don't have power brakes. Should this port plugged ?? My distributor is plugged into timed vacuum port and manifold port is not being used.
The pcv port at the front of the carb is capped, not being used. I have low vacuum 7" Could this be my low vacuum problem ??
Please advise. Thanks, Peter
Le Mans Master
Joined: Feb 2001
Posts: 6,317
Likes: 287
From: Ocala FL
I'm not sure what you have set up, but it sounds like you have direct vacuum off the passenger side. That would be a source of low vacuum, because it is essentially open to the world.
A 327 block should have the rear draft connection near the oil pressure port by the distributor. This connects to the PCV system. Is this missing? Is it plugged? Do you have a non-327 block?
A few pictures would help everyone see what you have and give them an idea of how to fix it.
A 327 block should have the rear draft connection near the oil pressure port by the distributor. This connects to the PCV system. Is this missing? Is it plugged? Do you have a non-327 block?
A few pictures would help everyone see what you have and give them an idea of how to fix it.
Team Owner
Joined: Oct 2000
Posts: 38,897
Likes: 1,925
From: Washington Michigan
I noticed that the previous owner has engineered the PCV sytem with a hoses coming out of the valve covers (LT1) style. One hose with pvc valve from the driver side valve cover attached to air cleaner base and the other is attached to pass. side valve cover and is connected to the power brake port ???? I don't have power brakes. Should this port plugged ?? My distributor is plugged into timed vacuum port and manifold port is not being used.
Or, if you don't like the valve cover setup, you could use stock parts for the application, that will work - An oil fill tube from a '66 or '67 with a threaded bung in it for a PCV valve and a 3/8" hose to the PCV port on the carburetor, and the correct adapter tube assembly that goes in the vent hole in the back of the block and connects to the elbow in the air cleaner base with a large piece of rubber hose.
You should also have the vacuum advance line connected to full manifold vacuum, NOT "ported" or "timed" vacuum.
Thread Starter
Instructor
Joined: Jan 2007
Posts: 126
Likes: 0
From: Southern, Ontario
John,
I will probably chose option one. I believe you are right the system is connected backwards.
I would prefer to have option two, closer to stock but the edelbrock manifold does not have an oil filler tube.
Do you think my low vacuum problem is from this poor set-up ??
I will probably chose option one. I believe you are right the system is connected backwards.
I would prefer to have option two, closer to stock but the edelbrock manifold does not have an oil filler tube.
Do you think my low vacuum problem is from this poor set-up ??
Team Owner
Joined: Oct 2000
Posts: 38,897
Likes: 1,925
From: Washington Michigan
If it's actually connected as you described, "the other is attached to pass. side valve cover and is connected to the power brake port ????", you have a GIGANTIC vacuum leak, with manifold vacuum pulling crankcase fumes full time.
Option one should work fine for you.
Option one should work fine for you.
Team Owner
Joined: Oct 2000
Posts: 38,897
Likes: 1,925
From: Washington Michigan
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Thread Starter
Instructor
Joined: Jan 2007
Posts: 126
Likes: 0
From: Southern, Ontario
John,
I removed the valve cover and the elbow had a barbed end and the grommet was rock hard. Cut it out ,replaced it PVC system is hooked up as per your suggestion and working fine
I also hooked -up my advance line to the manifold vacuum. Idle has increased to 1200rpm from 750. I adjusted the idle back to 750 and when I touch the throttle it goes back to 1200 stays for bit and decrease then increase. Initial Timing is 14 deg. at 750 rpm with vac. adv. unhooked and manifold port plugged.
I suspect I have to make a dist. can or springs adjustment. I read your posting on this topic. I understand the concept just not sure how go about it.
I took the car for spin and does start better respond better with manifold vac connected to the adv. line.
Any simple steps that a novice could try.
Peter
I removed the valve cover and the elbow had a barbed end and the grommet was rock hard. Cut it out ,replaced it PVC system is hooked up as per your suggestion and working fine
I also hooked -up my advance line to the manifold vacuum. Idle has increased to 1200rpm from 750. I adjusted the idle back to 750 and when I touch the throttle it goes back to 1200 stays for bit and decrease then increase. Initial Timing is 14 deg. at 750 rpm with vac. adv. unhooked and manifold port plugged.
I suspect I have to make a dist. can or springs adjustment. I read your posting on this topic. I understand the concept just not sure how go about it.
I took the car for spin and does start better respond better with manifold vac connected to the adv. line.
Any simple steps that a novice could try.
Peter
Last edited by 6t5silver; May 20, 2008 at 06:57 AM.
