DIY Two Way PCV System How-To (HoMedepoT style)
 

From boredom and experimentation, along with some ideas from d-series.org on bi-directional pcv systems like what you see on factory turbo cars, I decided to make my own.

I did everything from HomeDepot Parts.* Probably spent $30 including a catch can I incorporated into it.

http://67.168.197.110/catchcanpcv/diagram.jpg

The parts list:

Husky Air Compressor Filter w/ 3/8" NPT threads (air/water separator)
10' spool of 3/8" ID 5/8" OD Vinyl Hose
10 hose clamps to fit 3/8" hose
3/8" barbed T fitting
Two 3/8" NPT to 3/8" Barb fittings
Two 1/2" to 3/8" adapters (I used a gutted pcv valve for one of these, and a plastic piece I found at homedepot for the other, it was a last minute grab I almost forgot about)
2" piece of 1/2" Hose
2 stock honda PCV Valves (holy ---- theres one right there on your intake manifold!)
3/8" Barb to connect to your intake tube (your choice how to do this, I didn't do it cause I dont have a filter or anything)

Here's How to do it:

Step 1: put the 3/8" NPT to barb fittings into the husky filter.

Step 2: remove the stock PCV Valve and hose that runs to the Intake Manifold.

Step 3: Mount the Husky Filter (catchcan) in desired location.* I chose right behind the intake on the firewall.

Step 4: using a 1/2" to 3/8" adapter and hose clamps, connect the 'IN' side of the catchcan to the stock PCV valve location using some of your 3/8" hose.* This connects your catchcan to your breather box, without having to get under the car.

Revision:* Tho pictured here is a filter on the valve cover breather, its not a bad idea to T it into the line between the crankcase and the catchcan so taht the head is being ventilated as well, this however can be skipped without problems if you wish.

Step 5: Using a short piece of 3/8" hose and of course more clamps, connect the 'OUT' side of the catchcan to the 3/8" T Fitting.

Step 6: Continuing to the other side of the T fitting, using another short piece of 3/8" hose, connect the other 1/2" to 3/8"* adapter to the T fitting.

Step 7: Use the short piece of 1/2" hose you have to connect the stock Honda PCV Valve to the 1/2"-3/8" adapter that you just attached to the T fitting.*

Note: This is a good time to replace the PCV Valve, they're cheap, and its piece of mind, so do it.

Also, if you can find a pcv valve or check valve that has 3/8" barbs on both ends, you can skip the adapter and connect the pcv directly to the T fitting with 3/8" Hose.* I personally could not find one in stock anywhere in town, but if you can get hold of a 1991 Saab 9000 Turbo PCV Valve, I believe it has what you need.

Step 8:* Connect the 1/2" side of the PCV Valve to the normal port on the intake manifold where it normally connected before we started.

At this point you're almost done.* There is one open fitting left now, and that is the third barb on the T fitting.

Step 9: Connect a 3/8" barb fitting to the tube between your turbo and the filter on the inlet side.* Run a hose from that barb up to the open barb on the T-fitting.


Revision: although not pictured here, somewhere on the line running from the T to the turbo inlet, you should have another PCV valve installed that is reversed in direction.* That way when out of boost that line will be sucked closed by the intake vacuum and you will only be pulling air from the crankcase.

Note: On my car I do not run a filter or tube off the inlet, so I dont have a place to connect this hose.* However, having it just open vented should still at least let the crankcase breathe without restriction under boost.* I ran mine in front of the radiator and pointed it back toward the rear of the car.* Maybe the fan will provide some suction, lol

Step 10: You are done, make sure the port on the bottom of your catchcan is closed, and go rip some panties.* Just make sure to do it at 100% throttle, not 66% like hotrex does ( ----- :p )

What you have just created is a pcv system with two paths.* One one path the normal pcv valve will provide vacuum until you boost, at which time it will close.* On the other path, when the PCV closes in boost, the suction from the turbo inlet pipe will provide vacuum to pull vapors from the crankcase.* The end result is constant crankcase ventilation.* There is concern that sucking on the crankcase vapors from the turbo inlet would suck shitty oil gunk into the* turbo and then you'd be burning oil, but thats what the catchcan is for.* The catchcan location was chosen so that it was filtering the vapors before ventilating to either path 1 or path 2.

Here are pictures of the system installed.* Note I did this in about 1 hour, stopped to eat, and have not yet mounted anything properly.* This was just to get it in the car and on its way.

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

good job fooky :-* i was gonna do a similar set up and do a write up, but my car doesn't seem to want to stay in one piece long enough for me to do anything but replace pistons :P i'll give you your 15 minutes of fame.....

STICKEEEEEE

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

what you need is a D16 ;)

woo woo sticky! :-*

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

you ------- hypocrite ::)

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

hahah ownage...but geez i would have got black hose instead of that white clear stuff

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

I run the clear line to the turbo just so I can see if my air/water seperator is doing the trick

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

hrm, fook, after looking over your set up again, it's pointless to even incorporate the stock pcv set up in to this 'breather'. under vacuum, the pcv will be open (simulating the stock purpose) and boost, it will be closed and the crank case pressure will bypass up past where the 'stock' pcv use to be and then vent out through your open hose, correct, is this what you had in mind? however, when in vacuum, and the pcv valve is open, it is in fact just going to serve as a huge vacuum leak the way you have it set up. it'd going to pull from the IM, through the open valve and then pull air from the least restrictive location, which in this case would be your open hose that is used to actually vent the pressure under boost :-\

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

i had to re-read what you said a couple times.

under boost, no this would not serve as a vacuum leak, as the pcv would be closed, and if operating properly, no air is getting thru to the open vented hose

under vacuum, no it would not either, a pcv valve only allows flow 1 direction, into the intake manifold. for the open line to be a vacuum leak, the force of the engine vacuum from the pcv signal line at the intake would have to be weaker than that of the open hose hooked to the intake tube on the turbo inlet side, not really gonna happen until boost is built up, at which time the pcv closes anyways.

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

no, of course it won't be a vacuum leak under boost, there's no vacuum, the pressure from the crank case will go through the charcoal canister, up the 'stock' pcv route, in to your seperator, and vent out the hose, you're right, it will work properly under boost and the pcv valve will be closed. however, when you're in vacuum (idle and cruising), the pcv valve will be open, look at your pictures, vacuum will be pulling on the hose off the manifold, the pcv valve will be open, and it will be sucking air through the vent hose because that's the path with least resistance, it won't be pulling through the stock pcv valve route like i think you had in mind. one easy way to fix that though would be to put another one way check valve in your 'vent' hose that will be close under vacuum and open during boost (opposite of the pcv valve), then when in vacuum, the manifold would be pulling from the crank case as opposed to to open air from the vent tube how it is now. see what i'm saying? the way it's hooked up now (only thinking about vacuum, don't even think about under boost right now) would be the same as having an open line off the intake manifold, which is a vacuum leak.

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

I see what you're saying. You think that the open hose in vacuum will take away from the suction to the crankcase? I guess that could be considered an issue. Like you said tho, another checkvalve or pcv valve flipped the other direction would cure that.

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

exactly, that's all it needs to be completely functional for venting the crank case in boost and vacuum.

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

edit, nevermind.

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

as with being a nube i was just wondering why this is beneficial???? and why somone might do this

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

ok so now its being argued that this system won't work because the pcv valve wont hold 100% so it will still see positive pressure in boost. this is being argued over on d-series.org. I say its still more effective than stock, and what they describe more sounds like faulty pcv valves over anything else. I am curious to hear what you guys think.

a stock pcv system just closes shut and the crankcase cant vent at all while in boost, this gives it a bath to ventilate while under boost. lack of crankcase ventilation can cause blow-by and own rings.

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

it's already been established that 9 out of 10 homo's prefer dseries.org because they're idiots. yes the pcv valve will close completely in boost, just as it does in the stock set up, that's the whole point to have 'breather' systems. here's what you need though, totally do away with all of that system, including the pcv valve all together and run one line from stock pcv location, in to your catch tank, and then going out of the catch tank in to a slash cut on the exhaust, here's the kit for 18 bucks http://www.secureperformanceorder.co...ProductID=5340 the exhaust passing by the slash cut creates a 'vacuum' pull that will be much more effective in venting the crank case, the more boost, the faster the exhaust gases move, the more it pull out of the crank case. same principle as putting it in the intake tube, but with less mess (no oily residue in your turbo) and more vacuum effect than the intake can produce.

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

ok, so i've got a b series but I think this still applies....

and slap me if i'm being a nube, but....here goes anyway.

1) Does this help with idle problems?
2) The shop that helped me with my turbo told me to just take a drill and basically run it through both ends of the PCV valve to take out the insides of it, and then run a line from the top of it, to a catch can.

setup seems to run fine, except I have an idle problem i've been troubleshooting for a while (surges) but I think that's related to the idle control motor.

alright, that's it. *braces for flames*

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

doesnt really effect idle...

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

wow, why don't you just run the tube inside the car and suck on it while in boost, do us all a favor ::)

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

maybe he'll suck on YOUR tube :-X

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

i ordered the exhaust slash cut kit, it ended up being like 23 bucks shipped. i'll keep everyone posted on how it works out.

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

I dig the exhaust slash kit idea, it'll be interesting to see how well it works.

projekteg- you should hook up a vacuum gauge to see how much the system "sucks"

Here's another thought i had, I don't know if the logic is right, but we'll see what you think.

PCV system wants to vent the crankcase- so under vaccum, the system is being "sucked" by the IM manifold. If you run boost (which you should), the stock system would close the pressure could build up in the crankcase = bad.

Basically, we want to be able to apply vacuum to the crankcase both under boost and under vacuum. Right?

If you run one of these (a vacuum reservoir designed for race cam muscle cars to help with power brakes) https://static.summitracing.com/glob.../sum-g1464.jpg
between the PCV valve and the crank case, (with a catch can in-between) you could potentially have vacuum at all times without the exhaust tube. I kinda like this idea better than the exhaust idea since if you end up getting oil sucked into the exhaust, it'll likely burn off and produce the scary blue smoke, in which case you may not be certain where it was from (blowby, stem seals, turbo seals, etc). I'd like to try and avoid any smoke coming from my exhaust.

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

Now can someone Draw a neat diagram of the install on a piece of MS paint paper and explain it, I get about half of what you told me, and the rest I have no clue...I'm a visiual person, and your pictures are sketchy to me...please and thanks.

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

I saw this in another toppic on this forrum (don't rmember witch one), why not put your vacum line to the intake before the turbo? it will create the necesary vacum if hooked up whith a 90 degree elbo facing the turbo and the catch can will do the oil separation part. Also if you are not using the stock check valve then you can connect your hose right to the oil pan under the intake (to save you a connection to the stock hose and make it look neater).

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

same principle as putting it in the intake tube, but with less mess (no oily residue in your turbo) and more vacuum effect than the intake can produce.

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

So any word on the kit yet?

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

http://www.fastbygast.com/Catagories...ion/Vacuum.asp

http://www.fastbygast.com/Images/Products/newstu.jpg



Ever wonder what that buzzing noise was coming from inside a Pro Stocker before they fired up? It's a Pro Stock secret... at least until we told everybody! That noise is coming from an electric vacuum pump. It's purpose is to evacuate the engine cases of unwanted pressures and make the piston rings seal better. The result is my favorite thing... HORSEPOWER! Well... almost my favorite thing.
Features:
Oil-less operation
Permanently lubricated bearings
Built-in cooling fan for constant use
Convenient mounting tabs
Closed housing and motor
Stainless valves and aluminum valve plate
Die cast aluminum head and diaphragm hold down plate
Balanced for smooth, low vibration operation
Long-life diaphragmHelps prevents oil leaks

Cheap money... easy installation... increased horsepower...

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

nice man ... but let me say whay one of the two ways WILL NOT work !

- so when you're under boost, the PCV valve will close and the system will provide vacuum from the tee line (going to the turbo inlet) - that's OK
- but when you're not under boost, the PCV vavlve will open and the vacuum will become available through the intake manifold ... BUT it will not suck through the catch can, it will suck fresh air from the firlter instead because it's gonna be a lot easier ...

solution: put one-way valve on the tee line as well :)

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

thats been discussed already, read the whole thread.

personally I am not running this setup anymore anyways. I just open vented the valve cover and crankcase to a catchcan.

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

damn I did read couple posts but not all of them ....
OK, my idea was the same :)
why did you change that system anyways, it seems to be functional ?

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

mostly because i didnt like seeing all that hose all over the engine bay.

that and i was too lazy to buy the second pcv valve for the other line, and without a turbo inlet pipe i cant really give that second line a good vacuum source.

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

i'm so glad i read like 5 pages of info on this last night ;D

Ok so basically there are 3 ways to vent the crank case. #1 is the PCV and the stock rout, but under boost it doesn't perform well. #2 is venting it into the intake before the turbo, but that makes the turbo and intercooler get all dirty.

now comes the great part, splicing it into the exhaust would be one of the better ideas so far if it were not for the whole burning off oil thing. But then again how much oil is gonna go into this hose? If it isn't much it shouldn't smoke considerable right?

then you can have a separate evac system. i'm considering going down to the local hardware store and looking at vaccum set ups for minor stuff.

Who knows maybe someday i'll join your fleets of turbo'd cars and know what this "boost" feeling is

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

lol, i haven't even used the 23 dollar exhaust slash cut kit i bought, i've just had my pcv completely removed and venting to atmosphere and it works fine, just not to enviroment friendly i guess :P

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

yeah its one thing to vent it into the air, but for power you need a vac to suck out the pressure in there. AND you figure the entire crank case gets to vent from what 2 areas???? so if you are only gonna vent it from one area it should Definitly have a vac source.

So now here i am thinking of what would be a cheap effective way to heavily draw gases from the crank case without sucking up oil. my head hurts

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

just run one of the already mentioned slash cut methods (exhaust or pre turbo intake) and use a baffled catch can in line. oily vapors are going to come out of the crank case regardless, that's why it's best in my opinion to use the exhaust slash cut method. who cares if you get a slight hint of smoke out of the exhaust under boost, it's not like you have to deal with it inside the car, and it's not like it will be so bad you'll have oil dripping in your exhaust or anything.

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

so its been a while since theres been any activity on this thread... but im about to do my own setup, and i want to do the exhaust method, but what kind of hose can you use so that it wont melt onto the fitting? seems like regular vacuum line wont be able to handle the heat.

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

I can't give myself a "stranger" anymore because my left hand is messed up :(

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

fix pics!

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

weld in a metal slash cut tube. and attach the hose as far away as you can. they also make a high temp hose that would help in this application. either way you need to use a metal slash cut tube. make sure you put a check valve in this line aswell.

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

Didnt the Dodge Caravan come with something like this stock, I think it has a metal tube running from the block to the exhaust

Re: DIY Two Way PCV System How-To (HoMedepoT style)
 

fook can you give me those pictures or get them hosted? i want to visually see this.