I tried using a brass 1/8 npt straight fitting to replace the pcv valve like many threads and roadrace engineering say to and it is to large.WTF I tried 4 different hardware stores and even brought my valve cover in with me to find a straight fitting that will fit and none did. I see forums that mention that you can hollow out the oem pcv, but I didnt find any how to do so. Anyone know how to do that? Article?

there's probably an easier way to do it but I cut mine open took all the shit out of it and welded it back together

Yes I need to know how to do this as well. I wonder if you can just drill out all the material inside.

I tried to drill it out but the guts would just spin so I gave up and bought a straight fitting.

If you're going to attempt to drill it out, first take out the spring using an ice-pick, or something equally as small/pointy. Then, use a nail jammed in one side at an angle to keep the internals from spinning. THEN, you better have a good bit, and it'll still take you a while.

OR go to the stealership, and order the brake-booster nipple off of the intake manifold. Just look under the hood, on the back of the IM, up by the throttle body. The threads on this piece are the same as the PCV, but the barb is larger, so you'll have to use bigger hose, but... that's no biggy.

Hope this helps.

dragrush said:

I tried using a brass 1/8 npt straight fitting to replace the pcv valve like many threads and roadrace engineering say to and it is to large.WTF I tried 4 different hardware stores and even brought my valve cover in with me to find a straight fitting that will fit and none did. I see forums that mention that you can hollow out the oem pcv, but I didnt find any how to do so. Anyone know how to do that? Article?

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Why not try running a 1/8" tap through the PCV valve threads on the valve cover. It worked for Dan (project_tsi) and I'll be doing it this week as well.

so why do you want oil in your intake manifold? or is this for a catch can or something?

tstkl said:

...or is this for a catch can or something?

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Exactly.

Disabling the pcv is a terrible idea but if you must, you can swap the pcv with the return fitting on the intake manifold since both has the same thread pitch. Or you can run a 1/8 npt tap through it like Paul suggested.

Thanks for all the input, all the ways above seem like they would work. But why is elimiating the pcv valve with a straight fitting a terrible idea? I need to do it because I am installing a magnus intake manifold.

dragrush said:

But why is elimiating the pcv valve with a straight fitting a terrible idea? I need to do it because I am installing a magnus intake manifold.

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Let's break down the functions of pcv and breather valve for different situations.

1. Under vacuum: The pcv valve opens and allow blow by (fuel mixture) to be evacuated by the negative pressure in the manifold and replace by fresh and metered air pulled in via the BREATHER valve which is supposed to be connected to the intake pipe.

2. Under boost: The pcv closes and blow by (crankcase pressure) is evacuated via the breather valve by the vacuum in the intake pipe.

So what happens when both the pcv and breather are both routed to a catch can and VTA instead of recirculating?

1. Change in the air/fuel ratio, rich to be exact, as blow by through the pcv valve is already accounted for in the stock feedback system.

2. Lack of vacuum in the system will result in contaminating your oil with fuel because of the lack of air recirculation. VTA will mostly relief crankcase pressure if the motor is in good health but does very little to swap air inside the crankcase therefore alot of fuel will end up in your oil. When I vented both to a catch can, my oil always smells like fuel, well the whole car really since it's VTA, and looked kinda greenish color. After I recircuated both back to the stock location, my oil smell and look (black) like oil again.

3. If the motor is in questionable condition, VTA alone may not provide enough pressure relief due to the increased amount of blow by, the consequences here is obvious.

With that said, Venting both is still a much better option than keeping your pcv but vent the breather valve like most people do.

Ok so just to get a yes or no on that oldman...

What's your opinion between the two, keep the PCV or vent it (taboo style)?

MyBeatGSX said:

Ok so just to get a yes or no on that oldman...

What's your opinion between the two, keep the PCV or vent it (taboo style)?

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Yes.

I have gone around the world on this subject, tried pretty much everything that is out there except rerouting to the exhaust like what Paul is about to do this weekend which still doesn't supply clean air to the crankcase, my opinion is keeping both the pcv and breather routed to stock location and install an inline (internal) catch can on each line to keep your intake tract clean. Some (Paul ) might say keeping the PCV is just another possible intake leak, I say change the OEM pcv every 2 oil change.

so umm.... what about us with the gm maf, in blow through, theres no way for the maf to account for the air the pcv lets in, so its going to run rich, isn't it? but unlike venting a bov, this type of venting is consistant, and directly proportional to boost, so theoretically it could be tuned for very easily, couldn't it?

tstkl said:

so umm.... what about us with the gm maf, in blow through, theres no way for the maf to account for the air the pcv lets in, so its going to run rich, isn't it?

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No, you will end up running lean due to unmetered air entering the intake tract through the breather valve, same effect as venting the breather valve while retaining the pcv.

but unlike venting a bov, this type of venting is consistant, and directly proportional to boost, so theoretically it could be tuned for very easily, couldn't it?

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You're right that it can probably be tuned out but keep in mind that most members who has installed a fuel filter on the breather has no tuning or logging capabilities. Also, the effects on air/fuel ratio is just a part of what is being discussed here, a small part in fact. You will have to deal with the tuning aspect with the GM MAF but recirculating will still ensure proper pressure relief as well as minimizing oil contamination, the bigger part.

tstkl said:

so umm.... what about us with the gm maf, in blow through, theres no way for the maf to account for the air the pcv lets in, so its going to run rich, isn't it? but unlike venting a bov, this type of venting is consistant, and directly proportional to boost, so theoretically it could be tuned for very easily, couldn't it?

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Still having problems with the shift key?

I just clamped it in a vise and pulled it apart with a pair of vice grips, but I did break the first one. On a side note. I'm prob going to put my pcv system back in place because I don't like the smoke coming out of my hood when i stop at a light, parking lot, ect.

I cut my PCV in half, dumped the guts out, clamped a hose onto it, and I'm running both this and my valve cover breather through catch cans, and then back into the intake. No problems here.

I've never had any of the problems mentioned above and I have both vented to a catch can with the PCV deleted, course then again I change my oil every 1000-1500 miles and it smells like normal oil... The catch can does smell like fuel though .... I have a wideband and frequently take it up to 8500rpms when shifting and I'm still running a very rich 10.8 AFR which I actually need to lean it out Via dsmlink but I've been to lazy.... I still have very bad Crankcase pressure though, I really don't know how to get rid of that..

Turbo Monk3y said:

I've never had any of the problems mentioned above and I have both vented to a catch can with the PCV deleted

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I still have very bad Crankcase pressure though, I really don't know how to get rid of that.. :

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Make up your mind, that sounds like a problem to me.

oldman said:

You're right that it can probably be tuned out but keep in mind that most members who has installed a fuel filter on the breather has no tuning or logging capabilities. Also, the effects on air/fuel ratio is just a part of what is being discussed here, a small part in fact. You will have to deal with the tuning aspect with the GM MAF but recirculating will still ensure proper pressure relief as well as minimizing oil contamination, the bigger part.

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To answer your question, recirculating will most likely solve your problem.

oldman said:

... you can swap the pcv with the return fitting on the intake manifold since both has the same thread pitch.

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This is only true on the 1g Intake manifold. On the 2g manifold, the nipple comes directly out of the manifold, not via a threaded fitting. That's why I suggested the Brake Booster fitting.

When is somebody going to write the definative "I hooked up an electric vacuum pump" tech article with part numbers so we can avoid all of this crankcase pressure issue...

I banged on mine with a punch til the nipple part tore through the body. Then i stuck it back in, bent the sheared shards back in place and jb welded the barstard. Mine's setup taboo style for those wondering.

Since I have no place to re route the pcv hose, would putting a T in the break booster (with a catch can between the two) work since that line gets vacume?

dragrush said:

Since I have no place to re route the pcv hose, would putting a T in the break booster (with a catch can between the two) work since that line gets vacume?

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I would not. A good vacuum source is crucial to the proper funtioning of the brake booster, since the pcv is basically a vacuum leak if you will, using the brake booster line for pcv will reduce your braking power, also one of the reason why the BOV line should not be tapped for your mbc. I'm about to install my JMF SMIM with four fittings, perhaps you can weld a extra 1/4" fitting on your magnus.

oldman said:

I would not. A good vacuum source is crucial to the proper funtioning of the brake booster, since the pcv is basically a vacuum leak if you will, using the brake booster line for pcv will reduce your braking power, also one of the reason why the BOV line should not be tapped for your mbc. I'm about to install my JMF SMIM with four fittings, perhaps you can weld a extra 1/4" fitting on your magnus.

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I have a 1g JMF SMIM on my car right now and I'm not about to mess up the welds by adding another bung, Its been like this for over 2 years running low 11s I really don't see the need to change... Plus every time I take off the head The stock pistons are Clean they only have a slight amount of carbon on them which wipes off without effort. With recirulating Your Intake becomes very messy. Also If I was to hook up the valve cover vent back to the intake, Underboost that throws out some oil mist, slight but still some will eventually cake up in your turbo and then run into your intercooler... You make solid points but I would have to change alot of my setup to for something so small... If you know of an easier way that I could relieve some crankcase pressure I'm all ears. Let me know.