PCV Delete...

[Wicked]

Well,
I picked up a air/water seperator from work. Its bigger then the little ones that everyone else uses but I figured that'd be better to prevent a possible overflow condition. Anyway, I installed it tonight.

I plugged the pass. side head and connected the seperator to the driver side.

I'll watch it over the next few days/weeks to see if I get any accumulation.

Since the blower install I didn't have a complete PCV system. I had been running an open breather on one side and the PCV connection on the other. Well of course thats a huge vacuum leak.

I also tried just two breathers but they get oil soaked and start to drip everywhere. So i think this will solve my problem.

Pic...

[Sendero]

Is this just an experiment or are you going to re-attach your PCV system at some point?

[Wicked]

Is this just an experiment or are you going to re-attach your PCV system at some point?

No, I had run without the PCV system(open breathers) for quite some time, so this will be no different. It will also eliminate pressurization of the crankcase under boost.

If you're going to bring up the tuning issue, what's the difference between closed PCV and no PCV? I'll let the long term fuel trim take care of it for now.

[Sendero]

If you're going to bring up the tuning issue, what's the difference between closed PCV and no PCV? I'll let the long term fuel trim take care of it for now.

Thats another crossdrilled vs. slotted vs. blank rotors issue.

Just wondering because I am of the belief that vacumn that the PCV system creates encourages better ring sealing.

[TheJeanyus]

Thats another crossdrilled vs. slotted vs. blank rotors issue.

Just wondering because I am of the belief that vacumn that the PCV system creates encourages better ring sealing.
But would the same thing be true on a boosted motor? IIRC, Wall is running twin breathers and no PCV system right now, too.

[Wicked]

Thats another crossdrilled vs. slotted vs. blank rotors issue.

Just wondering because I am of the belief that vacumn that the PCV system creates encourages better ring sealing.

PCV does not use vacuum, it uses "ventilation".

But yes, racers use vacuum pumps to evacuate the crankcase to increase ring seal but they don't make that much vacuum, only a couple of inches of mercury according to my buddy.

I tried plugging one of the heads and just left the PCV connection to the intake vacuum connection and the engine starting making noise as though it was sucking air past a seal in the front of the motor. Engine vacuum is too high(or low) for evacuating the crankcase.

[Sendero]

But would the same thing be true on a boosted motor? IIRC, Wall is running twin breathers and no PCV system right now, too.

You're not in boost all the time...

[Wicked]

You're not in boost all the time...

But isn't that when you would want the better ring seal, at maximum cylinder pressure?

[Sendero]

But isn't that when you would want the better ring seal, at maximum cylinder pressure?

But isn't boost taking care of that?

[Wicked]

But isn't boost taking care of that?

No I don't think so, if vacuum seals the rings and normal driving combustion(1000psi) doesn't, then how could boosted combustion(2500psi) seal them?

We should look it up. :jester:

[Sendero]

No I don't think so, if vacuum seals the rings and normal driving combustion(1000psi) doesn't, then how could boosted combustion(2500psi) seal them?

We should look it up. :jester:

Nope, I already know the answer which is why I run my PCV system. ;)

[QWKSNKE]

I did the same as Wicked. For quite a few miles I ran my car without the pcv system. Had to go back to it because of all the blow by and oil that was coming out of my mini breather had stuck in it.

No harm in running without it. Doesn't cause any vacuum leaks, etc.

[Sendero]

I wonder if there is a way to run some type of remote oil seperator that drains back into the oil pan? Even better if you run an oil drainback for the supercharger, you could just piggyback off that system.

[QWKSNKE]

In a good sealing motor, there wouldn't be enough oil to worry about it.

[slvrbullit]

PCV does not use vacuum, it uses "ventilation".


Not trying to highjack or get any fires going here but If the PCV does not use vacuum, then how come when you remove the valve with the car running and place your finger over the valve hole there is enough vacuum to suck your finger to the hole?

[EZ SPEED]

This topic has been argued about 1,000,000 times on F150online.com with no real results.

I run a 03 Cobra PCV valve and the "dime" mod on one of my lines to restrict the flow under boost and I still get a little oil in the intake, but not as much as other people.

[Wicked]

Not trying to highjack or get any fires going here but If the PCV does not use vacuum, then how come when you remove the valve with the car running and place your finger over the valve hole there is enough vacuum to suck your finger to the hole?

Tommy,
I'm not saying it doesn't use a vacuum source, i am saying the crankcase is not under negative pressure. It only uses to vacuum source to create an airflow....thats why they call it ventilation.
Yes, if you disconnect the "high" side and feel the hole it will create a vacuum, but that side is not normally plugged. It is open to your metered air source BEFORE your throttle body. I tried plugging the pass. side and leaving the driver side hooked up to the vacuum but the engine vacuum cause some of my seals on the front of the motor to start "singing" as they created vacuum leaks.

As far as how to run a drainback, you could always connect a hose to your dipstick tube.

And I found out about the vacuum pump for ring sealing in racing. The general rule is a max of 12 inches of mercury...more than that and you need special seals, specifically intake end seals or you will suck them in...they sale valves to limit vacuum in the crankcase. He said his normally reads 3 inches or so, but 0 at WOT.

[Wicked]

Nope, I already know the answer which is why I run my PCV system. ;)

Whatever you say! :nice:

[QWKSNKE]

Not trying to highjack or get any fires going here but If the PCV does not use vacuum, then how come when you remove the valve with the car running and place your finger over the valve hole there is enough vacuum to suck your finger to the hole?

:slap: because the other side is under vacuum. :D

Like Wicked said, the crankcase is under positive pressure.

[slvrbullit]

Cool just gettin the info straight in my head is all. :nice: