PCV Delete debate

**kool-aide** · 12-26-2009, 05:33 PM

lol... i completely skipped that quoted section. now i will go back and read it, thanks.

**kool-aide** · 12-26-2009, 05:42 PM

Ah yeah, I was reading something that said the Sulfur would be present in the lubrication or gas. it also kept saying it was something to watch for on EGR engines. The article seemed to always talk about it in almost the context of diesel engines. I heard and seen labels that said diesel has a lot less sulfur than it used to. I guess where I was having a hard time believing an engine creates sulfuric acid was me thinking there was no sulfur in the mix. I guess I was kind of right, no more sulfur, lol.... I guess my curiosity was because I have read a few posts claim the PCV was created for this and that and this and everything.

Gee I just thought it was to reduce emissions, and help the engine live longer because you wouldn't have pressure build up in the crank. I thought I read some where the PCV was created back around WWII or something like that and GM released it royalty free or something like that. I was reading Wikipedia so I don't take that to be the absolute truth.

**astyles** · 12-27-2009, 09:23 AM

here in wonderful cali. catch cans are not smog legal.........isnt that stupid?

**kool-aide** · 12-27-2009, 09:33 AM

that sucks. yeah that does sound kind of dumb, i feel for you. In my state they gave up inspections and check points a long time ago. I was just a kid but i can still remember my mom taking the side road because the sticker was out of date, lol...

well I spent way too much time last night thinking of where to but my separator so I could plug it back into the intake and still catch oil. When I'm not sick as a dog I will go take a picture. All Santa gave me for Xmas was a cold. So for all you out there, don't piss of Santa.

**Blue28** · 12-27-2009, 11:50 AM

Originally Posted by astyles

here in wonderful cali. catch cans are not smog legal.........isnt that stupid?

Just do what I did, and mount the catch-can down below the passenger side headlight right off the frame rail with it mounted it to an existing bolt/nut.

**kool-aide** · 12-27-2009, 12:27 PM

Originally Posted by Blue28

Just do what I did, and mount the catch-can down below the passenger side headlight right off the frame rail with it mounted it to an existing bolt/nut.

any pics? I'm using an oil/water separator. Limited bolting options.

**RageAgainstTheMinivan** · 12-27-2009, 01:08 PM

Seems like you really have a bone to pick about the pcv system. Remember where you are getting most of your info from. There is years of posts on this topic, that means there are several posts to ignore. Sulfuric acid? ignore it, consider that theory just dirty oil. There may be small amounts of it but too little to worry.

First, you have to understand what is happening with the pcv system in general. Then what is happening in a LS1. You only want the pcv during low power or cruising around, above that air just needs to escape. There is some air flow, not much. And yes that is because of the cheap little tin valve thingy. Where this whole subject gets complicated is under high loads (wot). Remember, you have 2 lines. One, the "clean air" line is on the TB. The other is the "dirty air" going to the intake.

Here is a quick table
CRUISE POWER
-high vacuum on the dirty line, pulling air through the pcv valve.
-clean air is flowing through the clean line, replenishing the crankcase.
-The crankcase has constant air flow. Normal "Positive Crankcase Ventilation" operation.

WOT
-Most amount of blow by is occuring, pressurizing the crankcase
-little or no vacuum on dirty line from the intake. Pressure from the crankcase is flowing through the valve.
-Since little air can go through the valve, the extra pressurized "dirty" is also blowing through the 'clean air' line to the TB. This is where oil mist is blown all over the throttle blade, gumming it up.
-High HP engines also blow out the oil dipstick if the the two pcv lines cannot let all the blow by out

HIGH RPM, THROTTLE CLOSED (ENGINE BRAKING)
-highest vacuum in the intake, pulls the hardest on the pcv. Any oil mist blown into the line during WOT is sucked in.
-clean air line is now flowing clean air back into the crankcase, normal air flow direction.
-ls1's may have blue exhaust from burning the oil mist that was blown into the intake from WOT

Now, you said your engine was stock. Stock HP is fine for the stock pcv, connect everything back up to the way it was. If you are concerned about oil in the intake then add a catch can in the 'dirty' line. Nevermind the clean air line. Just clean the TB with some carb cleaner every oil change. Also, dont use a breather filter. Its going to simulate a vacuum leak to the pcm and it will run rich. Also, oil drips out of it and smokes on the header. If you start modding then yes. But tune for it. When you get to that point, research some more.

What I've done: Ran a 3/8" hose from the pcv valve to the radiator cooling fan shroud. Attached a compressor line filter with a bendable bracket. Ran hose back up to the intake. Cost: <$40. At the track, I cap off the intake and TB lines and screw on the valve cover breather. The pcv is now deleted but just for the track. Reconnect for the drive home.

**kool-aide** · 12-27-2009, 01:52 PM

Originally Posted by RageAgainstTheMinivan

Seems like you really have a bone to pick about the pcv system. Remember where you are getting most of your info from. There is years of posts on this topic, that means there are several posts to ignore. Sulfuric acid? ignore it, consider that theory just dirty oil. There may be small amounts of it but too little to worry.

First, you have to understand what is happening with the pcv system in general. Then what is happening in a LS1. You only want the pcv during low power or cruising around, above that air just needs to escape. There is some air flow, not much. And yes that is because of the cheap little tin valve thingy. Where this whole subject gets complicated is under high loads (wot). Remember, you have 2 lines. One, the "clean air" line is on the TB. The other is the "dirty air" going to the intake.

Here is a quick table
CRUISE POWER
-high vacuum on the dirty line, pulling air through the pcv valve.
-clean air is flowing through the clean line, replenishing the crankcase.
-The crankcase has constant air flow. Normal "Positive Crankcase Ventilation" operation.

WOT
-Most amount of blow by is occuring, pressurizing the crankcase
-little or no vacuum on dirty line from the intake. Pressure from the crankcase is flowing through the valve.
-Since little air can go through the valve, the extra pressurized "dirty" is also blowing through the 'clean air' line to the TB. This is where oil mist is blown all over the throttle blade, gumming it up.
-High HP engines also blow out the oil dipstick if the the two pcv lines cannot let all the blow by out

HIGH RPM, THROTTLE CLOSED (ENGINE BRAKING)
-highest vacuum in the intake, pulls the hardest on the pcv. Any oil mist blown into the line during WOT is sucked in.
-clean air line is now flowing clean air back into the crankcase, normal air flow direction.
-ls1's may have blue exhaust from burning the oil mist that was blown into the intake from WOT

Now, you said your engine was stock. Stock HP is fine for the stock pcv, connect everything back up to the way it was. If you are concerned about oil in the intake then add a catch can in the 'dirty' line. Nevermind the clean air line. Just clean the TB with some carb cleaner every oil change. Also, dont use a breather filter. Its going to simulate a vacuum leak to the pcm and it will run rich. Also, oil drips out of it and smokes on the header. If you start modding then yes. But tune for it. When you get to that point, research some more.

What I've done: Ran a 3/8" hose from the pcv valve to the radiator cooling fan shroud. Attached a compressor line filter with a bendable bracket. Ran hose back up to the intake. Cost: <$40. At the track, I cap off the intake and TB lines and screw on the valve cover breather. The pcv is now deleted but just for the track. Reconnect for the drive home.

Thank you. I have moved the oil separator over to the passenger side where I was able to connect the outlet back into the intake. The only thing I didn't do was put the PCV back in. My lovely factory boot ripped to shreds and I was tired of fooling with a fabricated hose. i would love to see pics of your setup. it sounds really similar to what i was trying to do. Did you use any street elbows? I was looking at mounting mine to the same place, but i wasn't up to a trip for street elbows, still sick. using just straight barb fittings causes the 3/8" hose to make some pretty hard bends.

one of the first things i noticed when i got the car was a pretty dirty throttle body, cleaned that up.

thinking about what you said popped a question into my head. if you leave the PCV valve out, would that help reduce the amount of stuff flying into the TB at WOT? I mean it seems like under WOT you can still suck oil into the intake through that TB line. Just curious what starts to happen in the system without the cool little tin guy. I would have put it back in butt the "cold weather" was kicking my butt and I said screw it, lol... Tomorrow is always another day.

I'm not all anal and paranoid or anything. Just felt like kicking around ideas and learn how the thing works. Heck I screw stuff up all the time, I don't sweat it.

**kool-aide** · 12-27-2009, 01:59 PM

oh and i don't have a bone to pick with the PCV system, unless you count that factor PCV boot that rips to shreds at the worst time, lol... I wanted to kick around ideas, air out the stuff I have read, and really dig into how the PCV works.

I was given the green light to spend all the time I want on my car, as long as it keeps me from playing video games all day and night,

.

So my hood is up a lot, even if it is for no good reason other than to stare.

I spent so much time fixing old worn out broken stuff on my 99 z28. I never had time to do anything else. This time around I can goof off and try more things, learn stuff at a less than panic route, well until i break something.

**RageAgainstTheMinivan** · 12-27-2009, 02:23 PM

Here's mine.

I didnt use any elbows. The hoses run alongside the radiator so there where no tight bends. Im not exactly sure what hose or boot that is shredded on yours but you definately want that replaced. You'll find out in hurry what happens if you connect the hoses with no pcv in it....massive vacuum leak!

I didnt run the air/oil separator, just an inline filter. seems to work fine, plenty of chocolate milk in the container after 1000 miles. Next thing you should do is take off the EGR and AIR systems if yours still has it. No HP gain, but it does keep exhaust out of the intake and cleans up the engine compartment.

**Blue28** · 12-27-2009, 02:37 PM

Originally Posted by kool-aide

any pics? I'm using an oil/water separator. Limited bolting options.

pm sent with link.

Not the greatest photos, but here they are.

The dot is hoses going to the catch-can.

Upper dot is the two hoses, lower dot is where the catch-can is.

The can is mounted to the frame rail after removing an existing nut, then reinstalling it.I had to remove the headlight to install it there.

**kool-aide** · 12-27-2009, 03:31 PM

Originally Posted by RageAgainstTheMinivan

Here's mine.

I didnt use any elbows. The hoses run alongside the radiator so there where no tight bends. Im not exactly sure what hose or boot that is shredded on yours but you definately want that replaced. You'll find out in hurry what happens if you connect the hoses with no pcv in it....massive vacuum leak!

I didnt run the air/oil separator, just an inline filter. seems to work fine, plenty of chocolate milk in the container after 1000 miles. Next thing you should do is take off the EGR and AIR systems if yours still has it. No HP gain, but it does keep exhaust out of the intake and cleans up the engine compartment.

Oh, you putit way down there. Man I never thought of that. Believe it or not I had my wife as my second eyes. She had some pretty good ideas for a location, and she doesn't know jack about cars, lol... But she had a couple of good ideas. Or she would ask what about there, or there, and then I would start thinking differently. Just shows how blind I can be. thanks for the pics.

**kool-aide** · 12-27-2009, 03:33 PM

thanks for the pics guys, beautiful.

Rage, did you need to pull out the fan shroud to mount it? I have pulled the fans once before, not my favorite thing to do, but not really hard.

What kind of bend able bracket did you use? I have some hanger fab stuff Plumbers use. It is 28 Ga metal you buy in the plumbing section.

**kool-aide** · 12-27-2009, 03:41 PM

I don't have the EGR, its an 02 z28. I get AIR codes all the time when I take the car our for a spirit run.

The boot that tears is the PCV boot, the rubber thing that the PCV sits in. I read another LS1 post that gives you an idea of what parts you can use to fab if you don't feel like getting the OEM part. My dealership prices on parts are freakin ridiculous around here.

I shouldn't have any vacuum leaks. Everything is plugged in, and for sure that PCV boot is not air tight with that metal grounding piece sticking out of it. I don't know what it is for or why it is needed. On my 99 z28 there was no metal thing sticking out. That metal piece is one of the reasons the boot tears apart. You pull on the PCV valve to replace it and it causes that metal thing to tug and cut into the PCV boot.

Any one have any idea why that metal "ground" part is for and why you need it?

**RageAgainstTheMinivan** · 12-27-2009, 03:47 PM

I just bought a universal bracket at menards with 1/2" self tapping sheet metal screws. Its kinda cheesy but it doesnt weigh much to want to tear out of the plastic.

The metal tab is meant for a heat sink. I think its useful in cold weather climates where the pressure drop in the valve could ice over with moisture.

**kool-aide** · 12-27-2009, 03:54 PM

Originally Posted by RageAgainstTheMinivan

I just bought a universal bracket at menards with 1/2" self tapping sheet metal screws. Its kinda cheesy but it doesnt weigh much to want to tear out of the plastic.

The metal tab is meant for a heat sink. I think its useful in cold weather climates where the pressure drop in the valve could ice over with moisture.

you think it is safe for us Southern drives to take it out?

like i said, my 99 z28 didn't have it. i didn'w know if GM made a change that was needed or if they just thought "hey this sounds like a good idea."

personally i have never seen something like that on a PCV before. then again i never went looking for one either.

**RageAgainstTheMinivan** · 12-27-2009, 04:53 PM

Originally Posted by kool-aide

you think it is safe for us Southern drives to take it out?

like i said, my 99 z28 didn't have it. i didn'w know if GM made a change that was needed or if they just thought "hey this sounds like a good idea."

personally i have never seen something like that on a PCV before. then again i never went looking for one either.

Id guess you can take it out. Its serving the same purpose for running coolant through the TB. I havent seen anything like it either before my camaro but most cars locate the pcv on, in, or near the manifold to get heat that way.

**kool-aide** · 12-27-2009, 05:04 PM

that was my thought too considering my 99 didn't have it and on my 99 the location was the same place.

what are the downsides to not running the PCV valve at all, just a 3/8" with no tin valve?

**kool-aide** · 12-28-2009, 12:09 PM

here is my catch can on the cheap.

http://www.cardomain.com/ride/2954870/1

at the bottom.

**Cutlass** · 02-28-2010, 10:58 AM

So Kool-aide, are you running a PCV/catch can/no breather setup without a pcv valve? Thats what I'm considering doing. Does it run ok? Seems like a PCV valve is a small/metered vacuum leak and without one would be a big vacuum leak.