BluEVOIX

iTrader: (69)

Something interesting that I have noticed regarding crank pressure...

Recently I have switched over to E85 and upon this conversion I have also changed my oil from 10w 30 mobile 1 to a 10w 40 amsoil . I am venting my pcv's so just by putting my hand over the vent tube, I have noticed with the thicker oil there is less air pressure being pushed out.

I'm running the stock motor and cams but with HTA green and supporting bolt on mods. So with the thicker oil it seems like I am getting a tighter seal with less blow by and crank pressure?...

Again this is just from a feel of hand, no real testing done. But its a pretty noticeable difference.

tscompusa2

iTrader: (22)

yes thicker oil will make the rings seal better.

tscompusa2

iTrader: (22)

if you can run his cap for awhile draining back ill pay for your oil analysis if you're using e85. id like to know how much it dilutes it. i initially almost bought his cap until you and a few others warned me about the oil issue.

tscompusa2

iTrader: (22)

theres a video that shows the suction of the turbo under boost, ill try to dig it up but its absolutely nuts inside with the camera in the intake.. no way a vented catch can can come even close to releasing that much pressure. it looks like a mini sonic boom

rodent

iTrader: (35)

I get LOTS of water in my catch can running E85. You can clearly tell its water when you drain it. I recently installed a quick drain valve on the bottom of my catch can with a tube that runs down to the bottom for quick drainage since it does fill up quickly.

I was only going to run Hals vented cap during racing or dyno and have a valve to open/close the line and have its own separate catch can. Regular catch can will run off the VC 100% of the time since of all the water it collects.

There's been other people having the same issues of water in the catch can when running E85 so its normal IMO.
http://highboostforum.com/forum/show...-oil-catch-can

I know the pro-bike racers run an electric vacuum to help with crankcase pressure and it gives them more power. Steve Johnson turned me on to this with his bike but I never got around to a vacuum solution. I know many racers use mechanical pumps but not much room for one of those. At least I now my engine can breath better with the larger lines and fittings off the valve cover.

BluEVOIX

iTrader: (69)

Your right, I was missing the point that the the drain would also act as a pressure relief from the crank case. So if the breather on the catch can is large enough to support the 3 ports, then the buschur can could actually be a power free'er mod. But I still dont like recirculating the oil. Just makes me uncomfortable with the condensation the lines or can might build especially since I'm on E85 now.

I have 36k miles on the car now and I started venting to atmosphere at around the 6-8k miles mark. Most of the time I was running 24 psi and now I've been running 31 psi. I never had the dip stick pop out issue.

Cant say much about the other reasons...

tscompusa2

iTrader: (22)

dont used a vented catch can unless the car has speed density.

look at this. look how much it sucks air. http://www.youtube.com/watch?v=F51xymg33-w

BluEVOIX

iTrader: (69)

One thing people should keep in mind. Lets say for example the turbo does help with sucking in the crank pressure. But at the same time, the check valve closes the exit of the other port from the intake manifold. So during WOT you only have one port open.

How much crank pressure does the turbo help relieve from only one port vs having both ports venting open?

tscompusa2

iTrader: (22)

valve cover to intake manifold

and

valve cover to air intake

are two separate things. the main discussion was can venting the valve cover to a catch can with a breather be more efficient then venting it to a sealed can recirculated back to a vacuum source (in this case the air intake since we have turbos)

With my setup id say its safe to say recirculating back to air intake will suck out more vapors/pressure, while promoting ring sealing and other things.

I was initially going to go with a 1 1/2" breather on a catch can, but decided against it after a bunch of big vendors, including FP themselves saying to run it back into the air intake.

For a drag car I can see making like 3 huge ports in the valve cover and running to a massive catch can with 2 1/2" breathers on it, but not for a daily driver that benefits from the additional vacuum from a sealed setup.

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You should not get any oil blowby at the turbo side anyways, the valve cover is baffled very well and stops most of it. When I cleaned my FP intake out with wd40 it had barely any oil residue in it from over a years of boosting 30-42psi.

The Intake manifold side does get a lot of oil into it when you use the stock pcv, because they fail after so much boost. usually from my research around 25psi on a evo pcv. pcv is just a one way check valve, so you can put another check valve right after it as a fail safe to stop the blowby going into the intake manifold, easy fix.

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What im doing for the intake manifold to valve cover side is: a seperate can that will separate the 2 trapping oils in the can before it can enter the intake manifold.. pretty much like a road block .. once it sees oil the can catches it then routes the air back into the intake manifold like stock setup. All I did differently here is upgraded the line to 3/8" instead of 3/4".

Then I will place a check valve inbetween the catch can line that runs to the intake manifold so it can not put pressure into the catch can.

So in short, im just upgrading the existing stock system to support the additional power im making over factory.


hope this helps, and if i said anything wrong please correct me.

l2r99gst

iTrader: (2)

You really don't want to get rid of the PCV valve, if that's what you're getting at. The PCV system is there for a reason when the IM is under vacuum as well to help scavenge excess crankcase pressure and moisture as well. Completely removing the PCV valve on an engine isn't a good idea.

If you're not saying that and simply suggesting to add another vent for when under boost, that would be a good idea as well.

But, the turbo definitely helps scavenge the pressure due to the vacuum it creates while under boost.

RSMike

iTrader: (1)

with a lot of people currently running their valve cover ports to atmosphere (via a catch can and filter), is there anything wrong with just running that to the intake pipe? so both breathers are going into the intake pipe.
It just means that when you're not on boost (or just low airflow) that the crank case wont be at vacuum like the normal PCV setup...
You could even do a venturi pipe in the intake pipe (like that exhaust setup) to create even more vacuum in the crank case?

Cheers, Mike

BluEVOIX

iTrader: (69)

If your running the oem maf setup, you cant just recirculate one side and vent the other.

So with that in mind, if you recirculate (sealed) back into the turbo you have to run a check valve and recirculate back into the manifold on the other end. Unless your talking about people with speed density?

Now lets say you were on oem maf setup. If you keep the oem pcv setup, yes the turbo will provide vacuum but under boost the check valve closes on the other end. So you have only 1 exit port with X amount of vacuum to draw the air. Is that X vacuum through that 3/8 " hole (or what ever it is) enough or would you be better off with 2 3/8" ports venting ?

Either case I like having zero oil in my manifold, intake and intercooler system.

BluEVOIX

iTrader: (69)

What I am trying to say is, unplug the recirculation of the pcv's and vent them all.

You dont need vacuum scavenging etc... You just need release. The recirculation is there just for emissions purpose and not for sealing the piston rings. I've read a lot of those articles some saying its needed and some saying its not etc...

If you truely created enough vacuum under the valve cover to make that big of a difference, you will suck in a lot of oil and not as just in vapor form. The vacuum will lift the oil and when it does it will find its way around the valve cover baffles.

n2oiroc

iTrader: (33)

bingo! with the crankcase pushing it out and the turbo sucking it in no catch can will ever seperate all of it.

tscompusa2

iTrader: (22)

why do you keep bringing up the pcv valve? all the pcv valve is there for is to make sure intake manifold pressure doesnt enter the valve cover and pressurize it. its a a one way check valve.. i have a dual catch can so it is seperated therefore i will run from the pcv to the intake manifold..

Im using the air intake to suck out vapors from the other catch can.. there is a dual catch can setup being used here like this: http://www.saikoumichi.com/DC3_page.htm

cept with bigger inlet and outlets. i know what im doing, i put hours of research into it.