Am I correct on the PCV valve.
03-07-2008, 12:47 AM
#1
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Am I correct on the PCV valve. I bought a long block so there was no PCV stuff. Now it will be boosted.
I assume the driver valve cover vent goes to the intake tube by the tb for the drivers side and the passenger valve vent goes to the top of the tb. And the valley cover goes to the intake passenger side tube. Being boosted do I just add a check valve to all 3 lines. Also the rear of the intake (ls6) has break assist tubes. I'm not using factory breaking system and will not need these. Can I just cap them.
I assume the driver valve cover vent goes to the intake tube by the tb for the drivers side and the passenger valve vent goes to the top of the tb. And the valley cover goes to the intake passenger side tube. Being boosted do I just add a check valve to all 3 lines. Also the rear of the intake (ls6) has break assist tubes. I'm not using factory breaking system and will not need these. Can I just cap them.
03-07-2008, 08:59 AM
#2
The PCV system needs a way for air to get into the crankcase, and a way for air to get out.
If you want it to work as intended (vacuum pulling water and fuel vapors out most of the time), then you need a vacuum source (something behind the TB). There should also be a PCV valve/restrictor in that line so it's not acting as a huge vacuum leak at idle. And ideally there should be a one-way valve so boost doesn't leak around the PCV valve and pressurize the crankcase, when boosting.
For those who aren't boosted, a line between the air filter and the tb makes a good fresh air source. For those who are boosted, you need to either a.) run a breather for the fresh air source, or b.) put a check valve in the stock fresh air source.
The problem with not using option a.) breather for the fresh air source, is that the crankcase has no way to let off pressure when you are boosting, since the one-way valve is blocking it. You can push oil out of the dipstick, push seals, etc.
For those who don't care about the PCV system being functional (sucking out condensation, etc). a simple breather arrangement takes care of everything.
You can cap the lines on the back of the intake. The big one is for the brake booster, the small one is for the hvac controls.
If you want it to work as intended (vacuum pulling water and fuel vapors out most of the time), then you need a vacuum source (something behind the TB). There should also be a PCV valve/restrictor in that line so it's not acting as a huge vacuum leak at idle. And ideally there should be a one-way valve so boost doesn't leak around the PCV valve and pressurize the crankcase, when boosting.
For those who aren't boosted, a line between the air filter and the tb makes a good fresh air source. For those who are boosted, you need to either a.) run a breather for the fresh air source, or b.) put a check valve in the stock fresh air source.
The problem with not using option a.) breather for the fresh air source, is that the crankcase has no way to let off pressure when you are boosting, since the one-way valve is blocking it. You can push oil out of the dipstick, push seals, etc.
For those who don't care about the PCV system being functional (sucking out condensation, etc). a simple breather arrangement takes care of everything.
You can cap the lines on the back of the intake. The big one is for the brake booster, the small one is for the hvac controls.