Crankcase Pressure Venting
 

Hey, I currently have a sealed oil catch can setup with a check valve. When I go BNR S4, I want to make sure the crankcase is vented properly. The following picture is the most cost effective setup I found because all I would have to do is purchase the low cracking pressure check valve and filter from Damond Motorsports. What do you guys think of this setup?

Here is the link to where I got the info from;
http://www.mazdaspeedforum.org/forum/foru...iaries-141095/

And here is the setup;
Attachment 226148

I'm not looking to break the bank with a whole new setup. I just want something that works. Has anyone been running this setup? If so, how is it working out for ya? Thanks a bunch!

Check out our PCV setup blog post. I think it will answer all your questions.

Damond Blog - Bye-Bye Blow-By

Thanks for the quick reply. I'm just wondering if incorporating a second check valve with vent filter as pictured above will be sufficient enough. I am looking to purchase the check valve and vent filter from you guys. Also, at what psi does the check valve open at with the spring removed?

There is no way for us to know what condition your motor is in, how it was built, and how much blow -y you'll have. Unfortunately, that means there is no way to know if one vented can is enough for you without trying it.

We generally recommend a second can for boost pressure higher than 24psi. That is a guideline, not a law.

that should be sufficient as that is essentially the same thing as putting the vented cap on the valve cover. and I am running a similar setup without a can.

That's understandable. I'm on stock block. According to that thread I linked above, this setup should be good for about 28 psi according to the research that was done in that thread.

When I go BNR S4, I don't want to invest in a whole new setup, but would rather incorporate just the check valve and filter to relieve pressures.

So you run two check valves? One to prevent boost entering the crankcase, and one to relieve crankcase pressure/close under vacuum?

I am running the damond sealed OCC with check valve between PCV and IM. After upping the boost from 23 to 26psi on BNRS3, I noticed the OCC was catching a lot more gunk. I added the SP63 VC breather (requires gen 2 valve cover because twist on), and that seemed to do the trick after upping boost from 23 to 26psi on BNRS3. No driveability issues and no shift in fuel trims. So, whatever is easier to give the crankcase someway to VTA would do the trick. Whatever it is, it should close VTA under vacuum.

Probably remove the hose from the valve cover to the intake, add a check valve out of the valve cover to VTA breather and cap the intake pipe inlet side would do the trick.

I have an oem pcv valve in my valve cover connected to a filter and hose which i mounted under the baffle plate with a 10 an elbow fitting. So this valve is the same thing as the sp6 valve cover breather for gen 2 except i have gen 1. That's all it is a pcv with filter on oil cap except with my setup the baffle blocks oil where oil cap gets splashed by timing chain

One check valve between im and block and oem pcv in valve cover

Could you post a picture of where it sits?

That makes sense because the crankcase pressure will take the path of least resistance, which would be through the pcv, and into the catch can, in essence pressurizing the OCC to same pressure as in the crankcase. But seeing as how you've added the SP63 VC breather, the path of least resistance now becomes the breather cap.

This makes me think that maybe I should either buy a gen 2 valve cover and purchase the SP63 VC breather, or do what Nitr0Engie did. If I put a low cracking check valve and filter in between the OCC and manifold check valve, I will probably also be getting a prematurely filled OCC as well. How long/fast did your OCC fill up when raising boost to 26 pounds?
I'm wondering if I'd be ok with draining it more often or not. lol

Also, when you were at 23 psi, where you just running the sealed OCC and check valve and that's it? If so crankcase pressures must have been pretty high?

When I was at 23psi, I had just the sealed OCC and check valve. The OCC would fill up about 1/4 full over 5k miles.

Not changing anything else but adding boost up to 26psi or so, the same setup caused the OCC to get probably near full over 4k miles or so (with a lot of 3rd/4th tuning pulls also).

I added the vented breather and we'll see what happens. I did attribute the higher filled OCC to boost because nothing else has changed in the setup, and nothing suggests the engine has changed (i.e. fuel trims/tune still dead on). After a few k miles with higher boost and vented breather, we'll see what happens.

Yeah that vented oil cap is probably working wonders on your crankcase right now. I wouldn't be surprised if you see less oil in the OCC than you did at 23 psi.

Where did you get the vented breather??

Here is the picture

its a -10 AN Bulkhead fitting with a K&N filter I had to special order from discountauto and 5/8 pcv hose that i bought from either advances or oreily or autozone cant remember who sell its, but its cheap and it says PCV right on it, meant for PCV systems. and then some clamps.

when you take off the valve cover there is a baffle that you MUST use the right screw driver or you will strip the screws, press down hard and use a #2 Phillips, go slow, dont strip them

the bulkhead fitting comes with a shitty teflon sealing washer, i gobbed mine with black RTV and it doesn't leak.

Man your engine bay is bad ass!

I'm thinking of going with the JBR VTA kit and installing it in between my OCC and intake manifold check valve. That way when under boost, crankcase pressure/vapors can go into the catch can, get filtered, exit the catch can, and go through the VTA check valve and out into the atmosphere.

I noticed you made ports on the stock manifold. Was this for AUX fueling? Why are they capped off?

I've been reading that Damond Motorsports is working on an adapter kit for us to install the Focus ST intake manifold on our engine. Apparently the ST manifold only has a 2% flow imbalance between ports, where as ours has a 20% flow imbalance with a larger amount of air going to cylinder 3. Not to mention that the ST manifold flows significantly more air in total than ours. I saw it on there website. here's the link, I may go this route, but who knows, they said they will only have it for the gen 2's at first.

https://damondmotorsports.com/blogs/...ld-adapter-kit

Invest in a spring to hold down the dip stick, added insurance.

I don't think its wise to hold down the dip stick as it is a good indicator that your venting is not working so if your pushing out the dipstick then you know there is an issue.

i had direct port meth in those ports but went back to a single port.

Engine bay looks bad ass... question though... that stainless line over your PMM... a vent or unused from previous configuration?

thats my main Meth Line, not hooked up. I had it unhooked for awhile

Why'd you go back to single port?

Because I cannot prove how much fuel was being injected into each cylinder with the primitive injection technology of methanol and variance of the line lengths and pressure differences I felt it was safest to go back to a single big nozzle where all of the fuel is mixed with the air and then distributed by the intake manifold in a more equal method.

A meth injector is not a metered fuel source like a normal injector where you know exactly how much fuel your getting in each pulse with constant pressure.

Looks like you've got that BMW cyclonic air/oil separator on the main PVC line also...

Here is my setup :

http://i410.photobucket.com/albums/p...psm5lugcts.png
http://i410.photobucket.com/albums/p...pshmbermfc.jpg
http://i410.photobucket.com/albums/p...pspqtuskos.jpg
http://i410.photobucket.com/albums/p...ps7ql8coug.jpg
http://i410.photobucket.com/albums/p...pskhwxfgwd.jpg
http://i410.photobucket.com/albums/p...pshaliikfb.jpg
http://i410.photobucket.com/albums/p...psnl1uglvc.jpg
http://i410.photobucket.com/albums/p...psmfo1lmhx.jpg
http://i410.photobucket.com/albums/p...psji3ujwgf.jpg
http://i410.photobucket.com/albums/p...psnw9zqtpy.jpg
http://i410.photobucket.com/albums/p...pso5ldwd7l.jpg
http://i410.photobucket.com/albums/p...psqoxxbzbv.jpg

The objective of the system is to pull some significant vac at WOT (and let the crank breath easily at part throttle), and never get an ounce of oil in the intake pipe (the BMW cyclonic air/oil separator is being drained to the oil pan)

The engine as only been run at 15psi since my rebuilt last week, but the system run flawlesly up to now (oil has been dripping from the cyclonic separator intake port because I didnt put worm clamps, but the intake pipe as not a drip of oil)

Does anyone have any dyno graph comparisons from just venting the crankcase? I'm curious how much power could be had from just venting excessive crankcase pressure with all else remaining the same.

Dont know about the gain from venting the crankcase, but I can tell you that my turbo was leaking form excess crankcase pressure before the engine rebuilt...I also noticed that my turbo was more laggy than usual, and when the dipstick popped from the excess crankcase pressure, the turbo spooled like crazy (probably because the crankcase pressure was pressurizing the CHRA from the oil drain, and this affected the turbo performance)

Thanks that's interesting. What turbo were you running at the time? And what was your PCV setup like when this happened?

I was running the same Holset HY35 I have now (journal bearing turbo)

I had the PCV and valve cover vented to atmosphere (but keep im mind I had 3 broken pistons)