Hyaboosta

Ok I too like many have been searching alot of forums for pcv valve info and how to get the positive pressure out of the crank.I want to run 10lbs on my d17a2 but not till I get the pcv vlave straightened out. From what I understand this is how I will set it up to vent positive pressure. Correct me if I am wrong please.

Disconnect the pcv valve from the IM and plug the IM side. run one line from the catch can to the pcv valve and the other end to a vac source(I will be using the the intake pipe pre-turbo in hopes that once boost hits vac in the pipe will increase and remove the crank pressure more during boost.) Then just add a breather filter to the valv cover and I should be good right?

s2kdre

its a one way valve youre no gonna get pressure in the cranckcase with only 10psi
thats if you use the stock pcv system.

beepy

You will not generate vaccum in the intake. You need some sort of restriction to make vaccum, a restriction like a throttle.

Unless you are going to be in boost for extended periods of time, don't worry about it. Just use one of the many good methods of controlling oil vapor.

J337_UNIT

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by beepy &raquo;</TD></TR><TR><TD CLASS="quote">You will not generate vaccum in the intake. You need some sort of restriction to make vaccum, a restriction like a throttle.

Unless you are going to be in boost for extended periods of time, don't worry about it. Just use one of the many good methods of controlling oil vapor.</TD></TR></TABLE>

the intake to the preturbo is under vac constantly, and especially when that ****** spools up to 150,000rpms.

Hyaboosta

thats what was thinking. but how wouldn't 10psi build positive pressure in the crank case? even 1 psi is positive pressure that was not intended to be in the motor.

J337_UNIT

the crankcase will get pressurized somewhat, but not significantly to cause blow by... what i did was just basically keep the valve cover nipple open. that will blow air out of it, the air thats coming out of it is the crank case pressure coming up through the head and being released out of the that nipple, now the stock set up has it so that the nipple gets routed to the intake, and the engine ingests those fumes for emissions purposes. But running it open just vents it out into the air.

beepy

Nope. Stick a vaccum gauge in the intake side of your turbo. It will not create vaccum for the same reason that a turbo will not make boost with the charge pipes not hooked up. Flow != pressure.

Hyaboosta

so where would be a good place to get vacuume from for the other end of the catch can? or what else could i use to vent it?

J337_UNIT

ALot of people just say "get rid of it, remove it and call it a day"... On my b18b, its alittle bit different.. I have a 1 way check valve thats connected to the top of the valve cover, and that ONLY vents OUT and to the Intake manifold... as soon as the car boosts, and pressure is built inside of the manifold, the check valve would close, therefore not allowing the air to pass through that hose into the IM. AND i also have a valve cover nipple, which i just basically vent that out to the open air. SO when the car is not in boost, the ventilation of the crankcase is going thru BOTH the PCV valve AND out of the valve cover nipple... Then under boost, it ONLY goes out of the valve cover nipple. Even then, its not that significant amount of pressure coming out, because if it was, then the PCV valve thats on the top of my valve cover would blow off. So i was able to just leave the stock PCV set up the way it is. On your car i dont know what exactly needs to be done. You really should sit there and observe where the pressure comes out of, and study it kind of. Thats basically what i did. And ive been boosted for almost a year now on this same exact set up. Over 10,000 miles now. No problems with the PCV set up, and no blow by.

Si Shane

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by beepy &raquo;</TD></TR><TR><TD CLASS="quote">Nope. Stick a vaccum gauge in the intake side of your turbo. It will not create vaccum for the same reason that a turbo will not make boost with the charge pipes not hooked up. Flow != pressure.</TD></TR></TABLE>

In the same way that if you blow accross paper it lifts, there will be vacumn if you tap the suction pipe pre turbo.

Hyaboosta

so what are some ways other members have adressed the pcv problem?

beepy

We are talking about enough vaccum to lift a piece of paper. You couldn't even measure that vaccum in grams per square inch. For the PCV to work you need at least 5 or 6 PSI of vaccum. (or 10" of water in the SAE system)

You will not generate that by the turbo sucking on the atmosphere.

Si Shane

have you put a boost sensor in a suction pipe before?


if not,
how fast does the air move in there? the turbine spins very fast, we all know that much. Having a vacum in your intake manifold while the throttle body is open means that there is a vacum (maybe not as strong) throughout the whole intake, right?

Just hard to imagine that this large, compressed mass of air isn't displacing any amount of air significant enough to create any vaccum in the suction pipe.

should i go put my boost sensor into the suction pipe? see if i get some vaccum?

beepy

Lol. Air could be moving at Mach 30 and it wouldn't mean a thing when it comes to static pressure.

There is only 1 kind of device known to man that can significantly reduce the pressure in a moving stream: A throttle. Anything else and you are just talking about the infintesimal pressure drop from the accelleration of air (which is so small that it is completely ignored in any fluid dynamics problem involving air), or the pressure drop caused by wall shear, which again is tiny when dealing with fluid air.

Sure, you could stick your hand over the intake the the turbo and feel a vaccum. Why? Because your hand is acting as a throttle. But remove your hand, and stick a non-restrictive gauge in there and you will read only atmospheric.

In a similar test, you can try to change the air pressure in the room by punching it. Go ahead, punch it a few times and see if you can change the pressure in the room.

Hyaboosta

im just gonna get the catch can, remove the pcv and let the other end vent to the atmosphere. it will help relieve some of the pressure.

dasher

I'm shortly going to be done with all my testing various methods to ventilate the crankcase and make one final thread to address every PCV problem and solution.

In the mean time read this old thread I wrote with some preliminary tests...

https://honda-tech.com/zerothread?id=697498

b18bEKcoupe

If you have the turbo sucking in air and there is a filter at the end of the pipe it will crate a pressure drop in the pipe. That would mean that there is a vacuum in the pipe. Why do you think that the stock valve cover is routed to the intake pipe....because there is a vacuum. If a filter didnt create a restriction there would be very little vacuum but that is not the case. Just run the catch can to the turbo intake pipe and be done with it.

Si Shane

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by beepy &raquo;</TD></TR><TR><TD CLASS="quote">Lol. Air could be moving at Mach 30 and it wouldn't mean a thing when it comes to static pressure.

There is only 1 kind of device known to man that can significantly reduce the pressure in a moving stream: A throttle. Anything else and you are just talking about the infintesimal pressure drop from the accelleration of air (which is so small that it is completely ignored in any fluid dynamics problem involving air), or the pressure drop caused by wall shear, which again is tiny when dealing with fluid air.

Sure, you could stick your hand over the intake the the turbo and feel a vaccum. Why? Because your hand is acting as a throttle. But remove your hand, and stick a non-restrictive gauge in there and you will read only atmospheric.

In a similar test, you can try to change the air pressure in the room by punching it. Go ahead, punch it a few times and see if you can change the pressure in the room. </TD></TR></TABLE>

I am sayiung the suction pipe acts as the throttle. Like ekcoupe

And just to clarify, your punching analogy is comparing a HUGE static piece of air to a single moving object. The pressure of air ON your hand will change drastically as your accelerate your fist. The pressure of the air in the room will have minimal effects. We're talking about a large body of air moving with respect to a small body, and not how the small body effects the large body, but how the large body effects the smaller body.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b18bEKcoupe &raquo;</TD></TR><TR><TD CLASS="quote">If you have the turbo sucking in air and there is a filter at the end of the pipe it will crate a pressure drop in the pipe. That would mean that there is a vacuum in the pipe. Why do you think that the stock valve cover is routed to the intake pipe....because there is a vacuum. If a filter didnt create a restriction there would be very little vacuum but that is not the case. Just run the catch can to the turbo intake pipe and be done with it.</TD></TR></TABLE>


Modified by Si Shane at 7:04 AM 3/15/2005

Flr Power

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dasher &raquo;</TD></TR><TR><TD CLASS="quote">I'm shortly going to be done with all my testing various methods to ventilate the crankcase and make one final thread to address every PCV problem and solution.</TD></TR></TABLE>

Really all you need to do is to simply vent to atmosphere. You do not need vacuum applied to the crankcase at all. Just look at racing engines if you don't believe me.

dasher

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Flr Power &raquo;</TD></TR><TR><TD CLASS="quote">Really all you need to do is to simply vent to atmosphere. You do not need vacuum applied to the crankcase at all. Just look at racing engines if you don't believe me.</TD></TR></TABLE>

Venting to the atmosphere is fine. Vacuum assistance is better!

Race engines actually have vacuum assisted crankcase elimination. This reduces windage and eliminated oil contamination from blow-by.

This is nothing new. Moroso has been making and selling vacuum assisted pumps and exhaust evac systems for many years.

Si Shane

i'm going to put my boost sensor in my sucktion pipe today. Curently i have it set up to vent to before the turbo, so i'll just plug the sensor (non restrictive sensor that wont act as a throttle) into the nipple. The oil and **** that pops out of the head and ends up into the suction pipe definitly shows signs of violent conditions inside the pipe.

Guess i'll find out soon enough!

Hyaboosta

I think im just going to order a moroso vacuum pump for the vac. source. I was talking to one of my domestic buddies and he said that it work great. it's worth a shot.

dasher

moroso doesn't make a mechanical vacuum pump for hondas(just some domestics). The only company that makes them is Z10 and it only works with their whole dry sump setup. Be prepared to lose your AC and about 2 grand from your wallet.

They arent for d series either, so you are out of luck.

Hyaboosta

dam you and your rightness

flood

http://www.beesandgoats.com/bo...l#PCV

Your theory is almost right. The example you mentioned when you started this thread. Except you want NO PCV valve. The preturbo intake will work, air flowing across the opening of the fitting in the intake pipe will draw air out in the direction of air flow (the same reason water comes out the top of a straw when it is submerged in a glass of water and you blow across the top of it).

That link has all the info you should need.



Modified by flood at 11:09 AM 3/15/2005