WTF PCV Vlave Grounded?
Thread Starter
Burning Brakes
Joined: Aug 2000
Posts: 1,132
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From: Morganton, NC, USA
WTF PCV Vlave Grounded?
I'm in the process of modding my PCV system as the LS1 version is known to pass a lot of liquid oil that can gum up the intake manifold, intake ports and the cylinders. When you pull out the original PCV valve, you see that inside the rubber tube-like socket is an arc of sheetmetal connected to a No. 4 aluminum insulated wire, the opposite end of which is bolted to the block. Now why on earth would you electrically ground a PCV valve? Maybe it's just a tether and the aluminum wire is inexpensive?
On the LS1 forum, a lot of F body owners have modded their PCV system by either putting in an air/oil filter or catchcan, or by using a PCV valve from an S10 pickup. This valve has a 90 deg bend and goes into the same place as the original PCV valve. The part number they recommend is 12572717, and when I emailed Purolator to find out their interchange number, I was told that they don't make this becasue they found out the "valve" was just a shell with nothing inside. Well, another confusion factor. If there is no valve, there should be no resistance to flow out of the crankcase. And why does an S10 with a regular 4.3 L engine take a different PCV valve from an S10 with a 4.3 L Vortech? Both look the same from the outside. Is there a knowledgeable forum member out there that can educate us on PCV valves?
On the LS1 forum, a lot of F body owners have modded their PCV system by either putting in an air/oil filter or catchcan, or by using a PCV valve from an S10 pickup. This valve has a 90 deg bend and goes into the same place as the original PCV valve. The part number they recommend is 12572717, and when I emailed Purolator to find out their interchange number, I was told that they don't make this becasue they found out the "valve" was just a shell with nothing inside. Well, another confusion factor. If there is no valve, there should be no resistance to flow out of the crankcase. And why does an S10 with a regular 4.3 L engine take a different PCV valve from an S10 with a 4.3 L Vortech? Both look the same from the outside. Is there a knowledgeable forum member out there that can educate us on PCV valves?
Drifting
Joined: Aug 2000
Posts: 1,253
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From: Chapel Hill NC
The 'ground' you're referring to is, I believe, actually for conducting heat rather than electricity. I don't know about non-LS1/6 PCV valves but I can tell you the AMW catch-can works well on the street and pretty well on the track with the stock valve. Nice looking piece, too.
Pro
Joined: Jul 2002
Posts: 718
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From: Mason Mi
Originally Posted by tcmc5
The 'ground' you're referring to is, I believe, actually for conducting heat rather than electricity. I don't know about non-LS1/6 PCV valves but I can tell you the AMW catch-can works well on the street and pretty well on the track with the stock valve. Nice looking piece, too.
Look at my sig link to see the stainless version 
Last edited by whitelite; Feb 23, 2005 at 06:38 PM.
Drifting
Joined: Oct 2003
Posts: 1,540
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From: bloomfield nj
the difference between the valves is that the 1 is a "rattle valve" the 2 is a "restrictor".the restrictor is the one without anything in it.the difference is the "rattle valve" is like a door that opens and closes and the restrictor has a small hole in the end that restricts the amount of crankcase pressure developed in the crankcase.the rattle valve does the same thing,but the restrictor valve does it at a more precise rate.
the reason for the restrictor valve was to help with oil burn situation the earlier ls1/6 motors were having.[alot cars got this valve/then the ls6 valleypan and if the car still burned oil,most got the car re-ringed with the higher tension rings to stop the ring flutter].
the wire cable is used basically to keep the valve supported in the right position/angle.
sorry-used wrong terminology.instead of saying controls i used restrict.
a pcv valve "controls" crankcase pressure.
the reason for the restrictor valve was to help with oil burn situation the earlier ls1/6 motors were having.[alot cars got this valve/then the ls6 valleypan and if the car still burned oil,most got the car re-ringed with the higher tension rings to stop the ring flutter].
the wire cable is used basically to keep the valve supported in the right position/angle.
sorry-used wrong terminology.instead of saying controls i used restrict.
a pcv valve "controls" crankcase pressure.
Last edited by dpd; Feb 23, 2005 at 06:46 PM.
Melting Slicks
Joined: Jan 2003
Posts: 3,251
Likes: 4
There is a reason that the PCV valve is grounded. The valve inside rattles around and can build up static electricity. A good spark in there can run a fireball down into the crankcase and cause some serious injuries. You should leave it grounded if you keep the valve in line. the PCV valve is actually a flow modulator. As the vacuum drops the valve is wide open. When the car is decellerating or idleing the vacuum is stronger and the air flow must be modulated to lessen the flow. so the valve narrows and in the event of backfire the valve closes to prevent the flame from reaching the crankcase. Yea, it's a PITA but is should be retained.
Last edited by IM QUIKR; Feb 23, 2005 at 10:55 PM.
