WDRacing wrote:Having the valve cover VTA means there is no vacuum at all. If there are fumes, they just eventually vacate. It's not a method I'd recommend. This method insures you'll have very dirty oil.

Yea I got that, where I'm a little foggy is, if your VC is VTA, at idle wouldn't you be drawing unmetered air through
the crank case?

If the only means for air to enter the engine is the PCV valve, then regardless of the VC being open or not, the PCV is only going to allow so much air to enter.

I think I get what your saying. Appreciate it.

My pleasure. Make sure to make a new thread when you start working on your setup.

Hell, I've been thinking about doing something, mine is basically done though. For now
I've been working on this motor for the last 3 years and its been in 2 different S chasis.
I only found NICO like, 8 months ago and this forum has been immensly helpful.

That's good to hear man. The forum has been slowing down as of late. Glad to see we're still able to do some good.

I have read through this thread. I had a guy who wanted a set of bungs (don't ask why he wanted two)for a turbo Honda, so I took the opportunity to make my own. I think for now I will run a catch can, but I am seriously looking into getting a vac pump in the future.

I chose white for some reason to coat it, but don't think it will match my motor so I am actually going to sell this one and make another in a different color.
Forum has been slow, I hope it is only due to winter. I have been less and less inclined to get on here lately due to inactivity.

I found a DSM forum where those dudes were discussing PCV as well.
A bunch of them are running one way check valves between catch can and intake.
The web site is www.usplastic.com, search for Kynar standard check valve, if anyone is interested.
I'm thinking about running one myself, but I want to find out what kinda pressure my crank case
is seeing at WOT first. Once I do I'll post my findings here.

I'm not a big fan of plastic and I usually get all of my parts at Mcmaster.

http://www.mcmaster.com/#air-check-valves/=lfoxi9

If you do want something not brass, the nylon type with barb fittings at Mcmaster is part # 6079T56

Jmoore124 wrote: Forum has been slow, I hope it is only due to winter. I have been less and less inclined to get on here lately due to inactivity.

Yeah the ole KAT forum has been slowing as of late. Most of the old members have moved on to something bigger/better. My 240 needs a ton of work, from paint to suspension.

I think I'm goona do a write up on replacing the rear quarter panels before the end of the
year . I gotta alot of rust lol

WDRacing wrote:I'm not a big fan of plastic and I usually get all of my parts at Mcmaster.

http://www.mcmaster.com/#air-check-valves/=lfoxi9

If you do want something not brass, the nylon type with barb fittings at Mcmaster is part # 6079T56

The oil and vapors would deffinitely be hard on any
plastic. From what I see at Mc Master their valve is opened
by air pressure where the US plastic seems to be completely
closed in one direction.
PCV has always seemed very confusing to me, but after
every thing I've read I've got a handle on it now, pretty sure.

In my understanding, other than the obvious emissions regulations,
the only purpose of having a PCV system is to relieve crank case
pressure and thus decrease pumping losses.

The article highlighted on like the first page of this post,
even claims to have gained horsepower with a vacuum pump
system vs. VTA on a chevy V8, I think.

So, in theory, if we stop any boost pressure from making it
past the PCV valve we should decrease pumping losses.

I'll be checking crank case pressures on my motor soon
with and with out a check valve soon. Let you know what I find

Alrighty, I found that at idle my crank case had less than 1/2 psi at idle and just under
1 psi at WOT with 16 psi boost. So, I would think that a check valve is not needed.

If you use a vacuum pump, not only are you removing crankcase fumes, that contaminate your oil, your improving ring seal. The ring seal eliminates blow-by and keeps more bang in the combustion chamber.

Removing the blow-by from the intake manifold increases your effective octane ratio as well.

B, do you have a recommendation for a small, unobtrusive, inexpensive (universal?) catch can? I'm running my custom vent system and need a small tank with an inlet, outlet, and filtered vent. Ebay ones are too flashy and limited choices of shapes...

Circuit Sports has a mini one, but it's shiny. I guess you could spray paint it or something.
http://www.frsport.com/Circuit-Sports-- ... 26027.html

Not sure how well it's baffled inside though.

Saikou Michi is a pretty customizable option for catch cans.

Those are sweet.

Kinda looking for something with a more horizontal design, with 90* inlets on each end and a vented filter on top.

You might try emailing him and see what he can make. I had mine made to fit in the charcoal canister bracket and he said he can make pretty much whatever I wanted.

AZhitman wrote:Those are sweet.

Kinda looking for something with a more horizontal design, with 90* inlets on each end and a vented filter on top.

Since you want something horizontal you may have to DIY. Most of the catch cans I've seen are of vertical design.

ATI makes a catch can, but I don't think it's for crankcase venting. That doesn't mean you couldn't use it for that though.

Not sure how cheap you're looking for, this one is $84 at Summit.



You could add 3 bungs, 1 on each end and a one of top for a breather filter.

There is also this Mishimoto that is designed as a catch can for pcv. It's $93 at Summit. Again, not vented though.



Most of the stuff I'm familiar with is based on vacuum, so it won't have a breather of any sort.

Razi wrote:Circuit Sports has a mini one, but it's shiny. I guess you could spray paint it or something.
http://www.frsport.com/Circuit-Sports-- ... 26027.html

Not sure how well it's baffled inside though.

I have that can. I don't know what kind of baffling it has though.
Also, I bought mine around 4 years ago, and it doesn't have that
big allen head on top. Seems to work well though, I used an
extra fuel filter bracket I had to mount it.

I think that allen screw is so it can be vented or sealed. It would be a better unit if you could take it apart and fill it with steel wool.

WDRacing wrote:I think that allen screw is so it can be vented or sealed. It would be a better unit if you could take it apart and fill it with steel wool.

Definitely would be nicer if you could open it up.
I've been looking at the Isis square can, think I'm gonna get two and route one between
the VC and turbo inlet pipe.

Pretty sure saikou michi is a better choice as far as baffling goes.



You can put AN fittings on it, clock the inlets however you want plus select hose fitting size, and if you don't like the choices they have he might be able to make a custom one.

Ok so here's my diagram for how I am going to run mine. Seems inline with everything I've read here. This is also with Saikou Michi DC3 cans.



I like the idea of a vaccuum pump but I also want something simple and mechanical so I don't have to worry about it...

When my S14 goes back under boost, I'm going to install the header mounted evac system. But I'll have the venturi pipe just aft of the turbo. Hopefully it will produce some vacuum at WOT. I'd only be looking for 2-3lbs of vacuum. Any vac is good, because there is normally no vac at anything other then idle.

BTW, there is no image in you post.

I just fixed it.

The one person I heard of doing that said he normally didn't have alot of blowby, but with the header evac he blew tons of smoke at WOT. Killed my desire to want to go that route, however- I never looked around to see if it was an isolated incident.

You have to have a good oil/air separator inline between the venturi pipe and the valve cover. Otherwise you're just pulling oil fumes into the exhaust. Hence the smoke.

I've got a pipe coming off the block and one off the valve cover (N/A, race-built L20b). Wondering how I should set mine up with a system like the Saikou unit.

Does the current configuration use a PCV at all? If so, you'll put the catch can between the intake and the block. That's assuming the line from the block is the lower of the two air lines. The line coming out of the valve cover will be vented. The vented line is for when the block doesn't see vacuum from the PCV under open throttle conditions and allows the block to vent pressure instead of becoming pressurized.

I'd have the valve cover line also routed to a catch can. But that depends on how much oil comes out of it, which depends on how much blow-by you have.

Hook a boost gauge to the dipstick and see how much pressure you have in the block at idle and WOT. That's the best way to determine the next course of action.