I've studied a lot of PCV systems out there, but they all seem to miss one crucial element...what to do with the passenger side valve cover tube that feeds into the throttle body that supplies air for the PCV system.

Most fixes just address the PCV tube that feeds into the throttle body from the driver's side valve cover. For that, I used 3/8" hose from my PCV valve to a 12" tall canister constructed out of 2" wide pvc. The input side come in about halfway up the canister and the output is toward the top. The height differential should help keep oil out better.

Now for the other part...the passenger side valve cover. I've found that even when you address the driver's side PCV tube with a canister, it's not enough. At high rpms (especially at decel), there's too much pressure that builds up and this often forces oil from the passenger side valve cover into the throttle body. Smoke City!!! Putting a breather on top is a poor solution because oil can coat the breather and run down the valve cover. Not a neat solution for a car driven 24/7.

What I did was make a second canister for the passenger side valve cover too. I ran a tube from the passenger side valve cover to the middle of the new canister. On top of the canister is a breather. This way, if oil backs up and gets into the line, it will fall into the bottom of the canister. This totally eliminates the supply line from entering the throttle body. The valve cover will still always get fresh air. I thought my motor was smoking because it was worn out. After doing a leak down, it was excellent, so I looked for other areas as the culprit. Seems that just addressing the PCV tube was not enough. Had to build a 2 canister system. Works like a charm. Sorry, no pictures at this time. I will try to post some soon though.

 

I just ran a tube from the driver's side over to the passenger side, used a 3/8" tee, and feed them both into the catch can. Works fine and you only need one can.

 

So you eliminate the PCV then?

Thats what it sounds like 2 canisters dropping 1/2 way down the can with breathers on top, oil in the bottom, fresh air in and out the top.

Or did you put this inline with the PCV system?

 

No Eric, the PCV system is still intact. The driver's side still goes from the PCV valve to the canister, then into the throttle body (like the factory setup, but better). The driver's side valve cover is what's really different. It no longer vents into the TB. Instead, it feeds into a second canister with a breather on top. I like utilizing as much of the factory PCV system as possible as I don't want to be breathing oily/gas fumes in my daily driver.

Patrick

 

You are introducing a vacleak with this setup (though very small)

The fresh air line does not operate under vacuum. It is designed to provide the valve cover with fresh air supply while the PCV draws vacuum all in a closed environment. The only change I would suggest is to remove the filter and run a line back to the throttle body. This will keep the system completely closed while giving you the benefit of the cannister inline.
Cheers,
Chris

<small>[ September 04, 2002, 11:34 AM: Message edited by: Chris ARE 360 ]</small>

 

ok, got it.

I'm going to bring some breather elements with me to the track on Saturday Chris. I figuire I'll run 5-6 runs on the breather elements and check the oil level, then fill and run 5-6 with the PCV system stock and see if thats where some of the oil is going.

If it looks like the breather setup is doing better for me I'll build something like Patrick's and see if I can find a middle ground.

 

mmiller,

Of course I know what you're talking about. The problem with venting the passenger side valve cover to the throttle body is that under very high rpms, the passenger side valve cover gets filled with oil. Rotation of the crank tends to force more oil up on the passenger side than the driver's side. That's why manufacturers put the PCV on the driver's side. You may not realize that the passenger side line can get oil in it too. Granted, I could have just vented this back to the throttle body, but I wanted to eliminate any additional source of oil getting into the throttle body. Trust me, it was getting in there...especially on decel.

 

Patrick,

I've got the Greddy catch can on my car with black fuel lines. What if I tee'd the hose coming off of the passenger side valve cover (that goes to the TB) to the PCV hose going into the catch can, and then tee'd the return hose going into the intake to the hose going to the TB? In your opinion, would that work?

 

They say most of the oil gets sucked into the drivers side valvecover PCV fitting on near the rear. Under acceleration that area is totally submersed in oil <img border="0" title="" alt="[Sad]" src="gr_sad.gif" />

Needs to be better baffled and also catchcan'ed

 

Patrick,

The passenger valve cover hose that connects to the TB does not put oil in the TB or intake. It opens up on the front side of the TB. Like Chris said, it helps to vent the PCV system. Take your TB off and follow fitting the hose connects to the hole in front of the TB and you'll see what I'm talking about.

 

Check out my site...I have instructions to make a catch can setup, and if you just want to buy one, well, I sell them there too.

I have the kit on my Trans Am and it works very well. The clear tubing gives a good indicator of just how much oil spews into the intake - but not anymore! <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

 

Check out soslo`s catch can I`ll be making this one for my Z.

 

No linky, no check.... <img border="0" alt="[fight]" title="" src="graemlins/gr_punch.gif" />

 

Tryt this link: http://www.freewebz.com/soslo/foreman_oilcatch.htm

This still does not address the passenger side valve cover. That's the whole reason I did the two can approach.

<small>[ September 08, 2002, 04:42 PM: Message edited by: Patrick G ]</small>

 

Patrick I would like to see your setup. What side of town are you on? I am on the NW side. I just set up the forman can today and drove to Brenam an got a few drops of oil in the line going to the can.

 

Al,

I am on the NW side as well. Maybe we can hookup some time this week.

Patrick

 

Patrick lets try to shoot for next weekend. Starting a new shift at work this week. I`m near the Willowbrook area. I guess we can try to contact eachother later in the week on this PCV post. Looking forward to checking out your 10 second car.

 

Any updates...How is your set up working out Patrick??

Thanks in advance!