The deezums Catch Can
 

Deezums catch can method, with a little more documentation.

Order is as follows:

Intake mani -> 3/8 Hose -> Check valve -> hose -> oil seperator -> hose -> pcv valve -> valve cover

Start by modifying the oil separator. Basically what you do is take out the bottom drain with a 5/16 allen, and then stick a spring between the plunger and the thing that screws on. I had to cut one to size, you want it strong enough to hold it closed when you try and blow through it, but light enough that you can turn the handle to open the drain.



After you modify it you mount it. I made a simple bracket like this:

https://www.miataturbo.net/attachmen...ne=14 41080373

Then you route the 3/8 hose. I'm using a straight 1/4 npt to 3/8 hose barb on one side and a 90 degree on the other. Make sure you point the check valve the right way. You want to stop air from moving from the intake manifold to the oil separator. Also make sure you have the in/out ports correct on the separator.

I'm going to clean this up with some zipties and hose clamps but then were good to go.

https://www.miataturbo.net/attachmen...ne=14 41080373
https://www.miataturbo.net/attachmen...ne=14 41080373
https://www.miataturbo.net/attachmen...ne=14 41080373

And here it is doing catch can stuff



Parts:

Pack of Two 2 3 8" Viton Kynar Standard Check Valves Barb to Barb | eBay

Husky 1/4 in. Air Compressor Filter-HDA70403AV - The Home Depot

JEGS Performance Products 15973, JEGS NPT to Hose Fittings & Hose | JEGS Performance Products

:likecat:

Nice use of the compressor oil seperator, I may do the same on my build, does it fill up quickly?

Because in my experience pcv valves make sucky check valves.

Wrong thread Aiden, though I'd like to make it known I dispute your use of check valve as PCV valve. The Vatozone one is great, if you still pop the dipstick you need to look at opening the valve cover.

I fill it halfway in around 1K miles.

I don't remember if I uploaded this, but it was right near 1K.

https://www.miataturbo.net/attachmen...ine=1441088432

I just did this myself a month or two ago following a diy catch can article I found online. I also added some copper scrub pad material in the air compressor filter housing to help collect oil. Didnt add check valves and I'm on the factory pcv valve (2001). So check valves are a better idea than the 323 pcv?

A check valve is not necessary, the PCV valve is the check valve. This separator works by "slinging" the oil out of the air with centrifugal force. The copper you shoved in there is likely hurting it's performance, certainly limits it's capacity, not something I'd recommend doing.

If you still pop the dipstick with a PCV valve that passes the mouth test you need to look at increasing the flow through the valve cover.

See this thread, lots of good things here.
https://www.miataturbo.net/diy-turbo...re-test-80353/

You caught my ninja edit... :vash2:

Would using the check valve and not fitting the PCV valve be a worthwhile option? Tap a brass barb into the valve cover kinda thing

<p>Whats the flow on these seperators.</p><p>Thinking about the future. I could easily grab one with 1/2npt ports, stick some 8an hoses on there and vent the fuck out of my valve cover.</p>

<p>Agree to disagree.</p><p>I got a new PCV valve. dipstick went poppy.</p><p>Added check valve. Dipstick no poppy.</p><p>My pcv valve might have been a shitty one.</p><p>But check valve was like $3</p>

Call me convinced.

Intake mani -> 3/8 Hose -> Check valve -> hose -> oil seperator -> hose -> valve cover

The flow on these separators is probably measured in CFM, at like 120 PSI, so more than enough for anyone but Aiden :giggle:

Opening the valve cover should be done no matter what. Just because the dipstick quits popping doesn't mean the block isn't under pressure in high load conditions. Have an extra boost gauge, do some measuring like the videos above.

Did you check the PCV with your mouth, Aiden? If it seals completely how is it causing your dipstick to pop?

A check valve will (likely) have a much higher cracking pressure than a PCV, it won't open as much with the same vaccum. That's the point of a PCV system, the spring and weight of a PCV valve are specifically matched.

Whoa whoa wait a second. Are you running a vent from the opposite side of the valve cover? This setup on its own will do bugger all under boost...

Yes, a breather on the exhaust side valve cover. There is absolutely nothing that can be done in boost, unless you like burning oil in the exhaust or running an electric vac pump.

If you pop the dipstick in boost and your PCV passes the mouth test you need to enlarge the exhaust side valve cover ports so the blowby has somewhere to go other than your dipstick.

If your PCV is passing pressure to the crank you don't fix it by adding more PCV valves, you replace the defective one.

<p>Other side is open to a little filter.</p><p>Check valve = pcv.</p><p>Check valve $</p><p>PCV $$$</p>

https://www.miataturbo.net/attachmen...ine=1441141835

https://www.miataturbo.net/attachmen...ine=1441141835



This is how a normal PCV valve works, the plunger and two springs. This is how the OEM one works, except for some stupid reason OEM decided to stamp embossed letters on the sealing face of the plunger. Fine for a NA car, only time it ever has positive manifold pressure is a backfire, not so much for turbo. As you can see, though, there is more going on here than a simple check valve.

Almost all the aftermarket PCV valves I found still have letters stamped into the sealing face, this is bad, they all fail miserably at the mouth test.

This valve here does not fail the test, as it doesn't have letters in the face of the plunger. It is not $$$, it is $2.50 something and you can buy locally and check it before purchasing to make sure it works.

This is true Deezums catch can, and it will work :party:

https://www.miataturbo.net/attachmen...ine=1417733726

<p>How is that different than a check valve. let air by one way and not the other? It even looks just like my check valve.</p>

Because this one is set with a perfectly balanced cracking pressure by the use of a weighted plunger and two springs. You have no idea if the check valve on your setup is even opening, right? Is the can picking up oil?

<p>Haven't run it yet. But when I pulled the check valve out both sides had a nice coating of oil</p><p>It opens at .5psi. That is not much vacuum at all.</p>

<p>As long as the check valve opens easier than the PCV valve it wont interfere with PCV operations.</p><p>On vacuum PCV+Check valve opens</p><p>On boost check valve closes, who cares what PCV does.</p>

Argh! I feel like I'm talking to pat!

If it opens easier than the PCV, what exactly is it doing? Are you sure you don't lift the dipstick because of the restricted PCV flow of the check valve?

If you can't blow through this PCV valve and make it leak past, your turbo at boost will not be able to either. It is a check valve by nature, it is specifically designed to do what it does and it works, it's at the auto parts store right now for less than $3 and it works. Did I mention it works?

<p>I bought that one.</p><p>Dipstick popped.</p><p>I bought check valve.</p><p>Dipstick never popped.</p><p>I mean it opens easier under vacuum. Under boost no open.</p>

<p>Did i mention my dipstick didnt pop after installing it? :)</p>

Then it had to of miserably failed the mouth test, and you must have had one with raised stamped plunger or something.

<p>I sucked on that bitch as hard as I suck on your mammas titties, and she wouldn't open.</p><p>They both work.</p>

<p>Look at it this way.</p><p>A PCV opens under vacuum and (supposedly) seals under boost.</p><p>Mine is broken into 2 parts.</p><p>Check valve seals against boost. PCV opens under vacuum.</p>

Why are you sucking? You aren't supposed to suck, turbo's don't suck.

Look at it this way, your PCV valve was defective? You had a stuck ring, you ran into overboost unnecessarily hard, I don't know what you did. Since I replaced OEM with this valve I have no problems. Adding a check valve if you have no problems is silly. Go to the auto parts store and try this, if it don't work, enlarge valve cover ports as you should have already. If it still lifts, check valve? That's what I'm saying, don't fix shit with patches.

One thing I do know is that a PCV valve seals under boost, and you test that by blowing the shaft like a true miata owner.

<p>Maybe I blew, i dont remember. I bout the one that you found. Because we had the same dipstick problem at the same time.</p><p>Enlarge which ports?</p><p>What I'm saying is that the valve worked for you and not for me. Maybe you got a magic one, idk.</p><p>When I ditch this motor everything will be rebuilt from scratch, so this will stay.</p>

You are trying to make a place for blowby to go, or any stray boost that might push through before the valve snaps shut.

Did you look at the link I posted on the last page?

https://www.miataturbo.net/diy-turbo...re-test-80353/

This is quality shit here, and applies to all miata. We have more crankcase flow volume with more power, it only makes sense that we need larger port diameters to keep the same pressures.

Consequently, I don't think I will enlarge the PCV side. It only functions when not in boost, or OEM levels of power. I don't want to enlarge it too much, because too much is a real thing. The exhaust port is fair game if you leave the PCV port alone, or so my reasoning goes.

And if I got a lucky PCV valve I'd like to know for sure, more test points are good but only if we are looking for the same things.

<p>Did not enlarge holes. Do not feel like pulling valve cover.</p><p>How bout this.</p><p><strong>For all people following this guide:</strong></p><p><strong>The correct way to do this is to use a PCV valve that works.</strong></p><p>I'm lazy and put in a check valve I found on ebay.</p><p><strong>Do it the right way, don't be me.</strong></p><p>Better?</p>

Yes, and please post results if the valve I posted fails miserably for you. It is a $3 pcv valve and might not be the same from batch to batch.

<p>Bruh, i've said it like 3 times now. The valve you posted failed miserably for me. Which is why I now have a check valve.</p>

<p>Ugh, re-read that thread and now I want to pull the valve cover. But I just got it to stop leaking.</p>

You say you don't remember what you did, didn't even take it apart to see why it won't seal, don't even remember what you did to initially test it.

No data point for you, sorry!

<p>Data point is I bought the one you told me to and my dispstick still poped its cherry.</p><p>I have it all torn apart right now, I'll check when I get home.</p>

I bet there is a point where crank pressure can equal boost pressure, in which case extra resistance in the PCV line might save yo dipstick cherry.

Reintroducing the pressure differential by enlarging the exhaust cover port might get you back to just using this valve, unless of course the plunger is different and it can't ever seal even on a good day.

Or so my thoughts go, something else must be wrong, ya know?

<p>I would drill out the exhaust cover port. Except this is the first time I have gotten my valve cover not to leak, and don't want to fuck it up.</p><p>By all means my PCV valve might be different. I'm just saying that a check valve works every time. And isn't dependent on which chinese manufacturer vatozone bought from that week.</p><p>I'll take pictures tonight.</p><p>And go get a new one from autozone to compare.</p>

Crankcase pressure should be wayyy wayyy lower than boost pressure.

And your dip stick should not be popping out, if it is, something is wrong.

<p>GUISE, MY DIPSTICK IS NOT POPPING ANYMORE.</p>

Why does your valve cover leak? Mine doesn't, and I don't even think I have RTV on it any longer. Did it get chewed up, or do you have astronomical crankcase pressure blowing it out?

The only time I've had a dipstick pop out was when I cracked a piston in 1/2, FWIW. Hard to imagine any other situation that would cause it short of hooking the turbo outlet to the valve cover.

<p></p><p>Just little bits in places. Last time it was around the CAS. Before it was the little place next to the cams.</p><p>Its never a lot, just enough to annoy me.</p>

<p></p><p>Old pcv valve and old rings, popped my dipstick all the time.</p>

If your crank pressure ever gets anywhere near boost pressure the PCV valve will open, and you will eject a dipstick.

It happens a lot, and it's usually not a split piston especially if you still have some sort of PCV.

If you don't have PCV and it does pop, shit's fucked.

I would agree with the "If you don't have PCV and it does pop, shit's fucked"

And if you have PCV and it pops the dipstick, your PCV setup is bad too. Because the PCV should be non-existent from a functional standpoint while in boost. It's only operational in vacuum by design.

<p><strong>WHICH IS WHY WE ARE HAVING THIS DISCUSSION ABOUT CHECK VALVES AND PCV VALVES. BECAUSE WE ALL AGREE THAT AIR SHOULD NOT MOVE FROM THE INTAKE MANIFOLD INTO THE CRANKCASE. SO EITHER A CHECK VALVE OR BETTER YET A FUNCTIONING PCV VALVE</strong></p>

Yes, and you should try and fix the problem by figuring out what causes a functioning check valve to open when it shouldn't. If the valve is not defective, something else is happening to open it.

I suspect most people open a PCV valve with old tired rings and lots of blowby on high boost. If you enlarge the exhaust cover port and never allow boost pressure to be near crank pressure (any time! Between shifts, on launches, whatever.) you probably find your shit works all the time now.

I am talking to pat, yuuus!

It's known that the stock PCV valves suck for boost, I read that here years ago, I think Scott did a write up on it but it could have been someone else. People put the GTX PCV valve, or gutted the stock PCV and put an inline check valve that can handle the boost. I think the gutted PCV valve + check valve is best, as there were people who had a PCV valve fail and it spit the guts of the PCV into the cylinder head....

I don't see how that is possible, the other side of the PCV is a sealed container, the larger spring and plunger wouldn't ever make it past the valve cover and the baby spring would have a hard time of it. Were these miata people having the PCV fail, or some other car? If you were super paranoid, you could put some copper brillo pad in the baffling to make sure it would never happen.

See this m.net post for pictures, also shows the exhaust side baffle port thing and some of the holes I propose every turbo miata enlarge at the earliest convenience. The dude is right on when he says there are multiple strategies, so look at them all, and then look again before you do anything.

MX-5 Miata Forum - View Single Post - FNG in need of a little help!

Top is 1.6, I don't see how it could eat anything. The other miata, yeah, without brillo it could happen.

<p><img src="https://cimg4.ibsrv.net/gimg/www.miataturbo.net-vbulletin/958x504/80-oqgdr04_99281c886d8f892f12fb79791914ef102968ede4.j pg" title="" /><br /><br />&nbsp;</p><p>With that picture how does the pressure ever get into the baffles with that bit welded shut?</p>

It was miata BP motor, dunno what year or any of that.

I'll try to go buy a boost gauge and measure my crankcase pressure sometime. I'm curious what my setup would show, since the PCV is gone and it's just a breather hose on the other side.

See the two green arrows? There's a plate with a vent/oil drain that covers it.

https://www.miataturbo.net/attachmen...ine=1441151185

I'm not sure why they recommend welding that last bit shut, that's how the last bit of PCV baffle oil drains if I'm not mistaken.

This is a 1.6 cover, 1.8 are similar.

Pat, even without running PCV you'd obviously benefit opening up ports to relieve any crank pressure you find.

<p>Because oil can pool there under hard cornering. I remember that now.</p><p>Didn't know about the center entrance there.</p>

Welding that oil's only exit shut doesn't seem like a solution, though? I thought the fix for oil pooling was to open the ports up. If oil collects on that plate covering the baffle, it most certainly will pour out the PCV port the next corner you take. If the proposed green holes are drilled flush with the plate, maybe?

Air exiting the port will want to suck oil with it if the restriction is too small. It will do the same with brillo, so don't use too much. You want larger ports so air can still exit while not drawing more of the draining oil up with it.

<p>New PCV valve fail. Video of me blowing is uploading.</p><p>TPS screws are the perfect size for mounting the bracket</p><p>Pics and vids incoming.</p><p>&nbsp;</p>

https://www.miataturbo.net/attachmen...ine=1441160371

<p>I fucking hate my internet. It has been failing lately.</p><p> </p><p>TPS screws</p><p>Attachment 232794</p>

Deffo do not want. I never checked mine against my finger like that, mine may well be leaking a bit.

I wonder... if mine leaks I might try setting the valve face down on a hotplate then push the plunger into the plastic with a pin, try and melt the plastic valve seat to shape. Whatever leaking happens is probably just due to the mold lines on the plastic, it is a flat face plunger right?

But wait, just the fact that there is evidence of some leakage doesn't mean it's no good. He blew on that thing for some period of time, and the total space involved was virtually none, so my guess is that an entire crankcase volume would see next to nothing from a boost event lasting the time it takes to go through a few gears, no? :dunno:

Who knows? How much boost? Maybe it leaks worse when you apply 20 PSI instead of 0.2?

The easy simple proven way to fix this problem is install a check valve that's actually designed to see pressure levels that we turbo miata folks see.