How do you guys rearrange the pcv on your engines when converting to sc/turbo? (I suppose you do..)
Where do you connect the wg/boostgauge-hose?
I am installing my HP-kit, but doesn't have any instructions...
Any pics of your engines would help

Roger

 

 

the most reliable source of boost and vacuum is the brake booster line. Just T into. It is connected to the backside of the intake and it's size allows it to provide accurate metering.

 

Well until this last set of minor mods and repairs...I had the PCV completely closed off and just vented to atmosphere through a crankcase vent on the valve cover.

After taking the heads off and still having found Oil/carbon buildup in the intake and on top of the pistons, I decided no more. So I capped both the intake and the PCV.

But the oil smell and little drip out of the filter was pissing me off. So I purchased a Greddy Oil Catch Can and put it down by the steering rack. I used the old PCV check valve and put in line out of the PCV going into the inlet of the catch can. The outlet goes up hill (so to speak) into the Intake. I am just going to try it out.

I am still venting to atmosphere also, but hopefully this will only occur during boost. I could actually see vapor (when the PCV was capped off) at times during idling conditions because there was no vacuum to suck it into the intake, like the way the PCV is designed to work.

The vapor is a combination of oil/water so it moves differently than when in a liquid state. When it is reburned with fuel it carbonizes on top of the pistons. I am hoping it will not be too bad. Somebody said you can buy these little sponge like things to go in the catch can to help stop the vapor particulates. I am looking for some of those now. They also mentioned Steel Wool...but I cringe at the idea of any Steel Wool particles making their way into my intake...I would rather have some rubber/silicone material if something has to go there.

 

Fram makes a crankcase air filter p/n BA6662 I just cut it to size and use it in my catch can (2 layers) and it works great!
Intake has remained drier then a popcorn fart!

 

How many of you drives around with stock pcv with sc/turbo, and at what pressure?

When i look at some of the kits on the market i can't see anyone mention anything about pcv modification.

Roger

 

The folks selling these want to keep the upfront price as low as possible so you won't see it in promos. but if you don't remove the stock PCV valve and replace it with a strong check valve you're asking for trouble. The boost will exit the intake and pressurize the crank case and prevent the rotating mass from turning freely. Never mind the rings and main seals. It's a must on FI.
Now the PCV system in it's stock form sucks a ton of oil into the intake and reduces your octane and burns onto the piston top causing preignition and knock. On an FI engine where you are effectively increasing the CR with boost, a knock can break the cast pistons and blow the motor to hell. The check valve is $10 and a good catch can will cost between $60-$160 for the AMW variant.

Or a new engine $2000 stock to $4000 forged to replace the blown unit. It's a good question and an important component of forced induction.

Brass Check valve


Catch can mounted on front frame rail

 

I will go to Pep Boys and look for one..thanks alot!

 

Great info… is that with or without butter.

Mike

 

Where'd you get the valve from?

 

I don't think people use steel wool. The stuff people use has a similar use, but it is a totally different material. It is basically long strands of stainless steel all bundled together (that is also used for scrubbing). There is really no chance of it going into the intake. I'm not sure what it is called, but it is much different than what I think of when I hear steel wool.

Back to the original post, I think a stock PCV on a boosted car is a disaster waiting to happen.

A good catch can, check valve, and an isolated fresh air vent is the minimal requirement IMHO. You have to realize that the regular PCV will provide no pressure relief under boost, the pressure is going to go out the fresh air vent and it will be carrying lots of oil vapor with it. This oil vapor will eventually cause detonation if it finds its way into the intake and kills your effective octane.

If you don’t vent adequately, you will blow out your main seals.

 

I don't know if its Steel Wool either...but I do know there are many different types fo Steel Wool from Course to Fine...and some long stranded exactly as you described. I have scrubbed water spots off of windshields with Steel Wool....I wasn't talking about an SOS pad that one uses to scrub the sink with

I have had my PCV capped for awhile now. I am most likely just going to put some sort of element within my catch can and see if it helps to capture the vapor.

 

McMaster Carr

 

Thanks -- is there a specific part number you used? I browsed their site briefly but couldn't find a valve that did exactly what I thought it should do.

I have a nice brass check valve ($15) installed in my alky system that I was thinking about using for my PCV, but its crack pressure is 2-3psi and realistically these PCV valves need to open with virtually no pressure (errr vacuum) and close tightly under boost.

And these guys have a product that is clearly made for this purpose, and looks really nice, but I have a hard time spending $100+ on a check valve:
http://www.et-performance.com/krank_vents.html

 

I'm sorry I was in a rush and I should have given more specifics. Viton seals are chemical and temp resistant.
Maximum Pressure:
Viton: 1000 psi @ 400° F
• Cracking Pressure: 0.3 psi
• Temperature Range:
Viton: -20° to +400° F

PART # 7775K52 $11.90
1/4" x 1/4" pipe, female/female

 

Krank vent is an awsome valve Tony, I run one on my Harley.
Your right it's a little too expensive but a real nice piece.

 

I don't know if the Krank Vent is strong enough to hold back boost. It's a nice design but it is more of a reed valve that will fail with high boost. The McMaster Carr valve is good up to 1000psi and can handle the chemicals and heat. Plus it cost 1/10 the price. Here is the link to the patent for the Krank vent and you'll see what I'm referring to.
Krank Vent Patent

 

Thanks I ordered the McMaster Carr valve that you listed the part # for.
It shipped already and being their right here in Jersey I should have it Weds. or Thurs!
I'll get rid of the stock PCV that I have going to my AMW`catch can.

 

If you have a stock PCV in the system don't get rid of it just add the check valve between the intake manifold and the catch can.
Remember the PCV is also the metering device in the system, removing it may cause you to suck more oil.
The steel wool everybody is refering to is what our mothers used to clean pans with back in the 50-60's called a scratcher, I doubt it will retain much oil mist or vapor IMHO.

 

Don't worry about the stock PCV, it does meter the air but between the extra length of hose and the AMW with the filter media the air flow will be more restricted anyway. Leaving it in place will make it less effective. I know it looks cool but don't mount the catch can on the heads. Locate it on the front frame rail for several reasons; it's cooler there and the vapors will condensate better, it's slightly lower than the engine and the oil in the line will drain back into the can and it won't be affected by the engine vibration possibly aersolizing back into the intake.

The SS wool is not intended to retain the oil but to extract it from the vapors by greatly increasing the surface area the vapors pass thru. It's actually positioned at the top of the can and the oil drips free to the can bottom.
Opinions...we all have them.