speedyquest Posted June 23, 2015 Report Share Posted June 23, 2015 (edited) I know this topic might bring a bit of heated discussion BUT I'm hoping that the people who have honest interest in the topic can get a back and forth going, educate a few people and possibly help me decide on exactly how I will run my catch can setup. First and foremost I've done quite a bit of reading I and feel like I know just enough to be dangerous LOL. That being said I will show you guys two possible layouts I have thought about going with and list what I believe are the pro's and cons of each. Setup #1 http://i.imgur.com/LPSiIwz.jpg Pro's:--------Keeps the oem pvc valve in place and allows the system to help pull fresh air into the engine under light load (casual driving).Improves upon the stock oil separator setup and allows the system to see vacuum under boost conditions Con's:--------From what I understand the stock pcv valve setup can and will overpower the vacuum created at the intake of the turbo and will suck un-metered air into the intake (assuming your set up like I am and have a maf in blow-thru mode). The oem ventilation system was concerned with emissions and safety of the car being driven by people who changed the oil in many thousands of miles. This is important because the oem pcv system pulls crankcase fumes into the intake and burns them. This is great to keep some of the un-burned gas and contaminants out of the oil but isn't the greatest for engine performance. Setup #2 http://i.imgur.com/Yc89ElF.png Pro's:--------Like I talked about above the oem pcv valve setup pulls contaminants and oil residue into the motor and burns it. Plugging both the intake port and pcv hole in the valve cover along with upsizing the hoses used by the catch can would eliminate that from happening entirely. Removing the pcv system will eliminate the possibility of the intake vacuum overpowering the turbo inlet vacuum and pulling un-metered air into the intake and effecting my A/F ratios. This also has a very small added benefit of reducing possible places for vacuum / boost leaks. Con's:--------Removing the pcv valve entirely means that those contaminants that would normally be burned in the motor will no longer go anywhere and will instead get trapped in the oil. This isn't inherently bad other than from what I've read you will want to change your oil more regularly. This is definitely a topic I'd love to hear from all of you guys about if you have first hand knowledge. Final Thoughts: I really think I'm leaning towards Setup #2. A few reasons for this are I don't put a ton of miles on my car, its driven only in warm months (I live in Wisconsin lol) and I typically never make it to 5,000 miles in a season before changing my oil. Also I like the idea of simplifying the engine systems along with the fact that it will stop any possibility of allowing un-metered air into the motor. I'd love to hear everyones thoughts. Edited June 24, 2015 by speedyquest Link to comment Share on other sites More sharing options...
scott87star Posted June 23, 2015 Report Share Posted June 23, 2015 PVC is a plastic, polyvinylchloride, where Positive Crankcase Ventilation is what you want, PCV. Neither of your options has an oil drain back to the pan so add the con of having to dump the can periodically. Link to comment Share on other sites More sharing options...
ucw458 Posted June 24, 2015 Report Share Posted June 24, 2015 From what I understand the stock pvc valve setup can and will overpower the vacuum created at the intake of the turbo and will suck un-metered air into the intake (assuming your set up like I am and have a maf in blow-thru mode). Only when not in boost. The turbo doesn't make much vacuum out of boost anyway. Once you go into boost the PCV closes and the oil separator handles all the crankcase gasses. Oil separators are mainly for boosted motors because a PCV doesn't work under boost. But some NA cars have them too. They put them between the PCV and intake. It's a small amount of unmetered air. Easily dealt with by tuning. Plus a street car may see around 95%+ of its run time out of boost. Having the PCV drawing fresh air into the crankcase is a good thing. It helps prevent the buildup of contaminants in the crankcase that eventually turn to acid that destroys oil and metal parts. Link to comment Share on other sites More sharing options...
psu_Crash Posted June 24, 2015 Report Share Posted June 24, 2015 It's been discussed, but I'm in to see opinions since I'm always looking for a better setup Link to comment Share on other sites More sharing options...
polarisman14 Posted June 24, 2015 Report Share Posted June 24, 2015 I posted a similar question not too long ago and was advised to make use of a BMW X5 separator. The holes in the mounting bracket are in the same place so relocating it is no big deal and the inlet/outlet lines (and drainback to the pan, less of a concern) are a larger diameter so those of us running MPI or higher than stock boost levels need not worry. In my case it is OEM mitsu PCV valve (the aftermarket ones suck) to IM on one side, and valve cover breather to top port on separator, then middle port of separator to intake on turbo inlet pipe, drainback to stock oil pan location. 1 Link to comment Share on other sites More sharing options...
JohnnyWadd Posted June 24, 2015 Report Share Posted June 24, 2015 (edited) As with all problems proper diagnosis should be step 2 after identifying the problem.....so what is the problem with the stock system? (beside its clogged/neglected) I struggle to see an issue with the stock system. More boost (upgraded engine components) just means more potential for blowby/crankcase pressure. What can be improved to make the oil seperator be more efficient? Locate the can in a cooler engine bay spot? Modify the valve cover baffles? Bigger lines? better port in the intake to create the venturi effect? Yeah. Edited June 24, 2015 by JohnnyWadd Link to comment Share on other sites More sharing options...
speedyquest Posted June 24, 2015 Author Report Share Posted June 24, 2015 @scott87star - Thanks for pointing out my pcv / pvc typos (many). I fixed the post but I won't take the time to fix the diagram lol sorry. Your right neither option I presented is returning any of the oil and while it does require you check the catch can once in awhile, for my setup I personally am ok with that. It also ensure that "dirty" oil and moisture isn't returned to the oil pan. So that is a plus. @ucw458 - Yea your definitely right about the turbo not creating much vacuum at its inlet off boost. And your also right about the fact that the pcv system helps pull out and burn contaminants that would otherwise end up in the oil. I would be curious to know though, do you see no real benefit from just not having the motor burn any of that oil etc in the first place? Is it just such a small amount etc that the negative effects outweigh that fact? @JohnnyWadd - I do see your point and I agree with you in some sense, but I think its fair to say that the oil collection system was not designed and built with sheer performance in mind but instead they envisioned it working under an environment where people just drove the car daily and other than oil changes didn't do much. Setup #1 is essentially an oem setup with just better flow and no return to the oil pan and I'm guessing thats what you'd suggest. I guess ucw458 talking about acids breaking down the metal is the only thing so far that really has me second guessing removing the pcv portion. But again, any and all ideas and thoughts are welcome. Link to comment Share on other sites More sharing options...
JohnnyWadd Posted June 24, 2015 Report Share Posted June 24, 2015 (edited) @ucw458 - Yea your definitely right about the turbo not creating much vacuum at its inlet off boost. And your also right about the fact that the pcv system helps pull out and burn contaminants that would otherwise end up in the oil. I would be curious to know though, do you see no real benefit from just not having the motor burn any of that oil etc in the first place? Is it just such a small amount etc that the negative effects outweigh that fact? Turbo does not need to create vacuum, the incoming air and pumping effect of the engine creates vacuum anytime its runnning. Venturi effect. Anytime air is flowing the effect is there. Just the shape of the nipple in the turbo inlet will improve the effect. Take a piece of PVC pipe and cut a slant on the end and hold it out your window when driving , notice the difference when you turn the open end towards the direction of travel and vise versa. Now try it with a straight cut piece of pipe like the OEM system has. @JohnnyWadd - I do see your point and I agree with you in some sense, but I think its fair to say that the oil collection system was not designed and built with sheer performance in mind but instead they envisioned it working under an environment where people just drove the car daily and other than oil changes didn't do much. Setup #1 is essentially an oem setup with just better flow and no return to the oil pan and I'm guessing thats what you'd suggest. It was designed to work within it limits. Replacing the system without looking at how the components work together will gain you nothing but bling and bragging rights for having BMW or Ebay parts on your car. Obviously it was not designed for sheer performance, it was design to meet many specs of exhaust and evaporative emissions and keep a vacuum on the crank case. Improve the existing system by enhancing its function. Get it? It uses vacuum, so improve the vacuum port. It pulls vapors through tight baffles and small I.D. hoses, so use bigger ones and mod the baffles. Edited June 24, 2015 by JohnnyWadd Link to comment Share on other sites More sharing options...
ucw458 Posted June 24, 2015 Report Share Posted June 24, 2015 Almost all cars nowdays have a pcv system. Even my 67 ford had a pcv. It works great on the street and for most cars has no ill affects. But if you're building a racecar you don't want any oil mist in the intake. You would run a vacuum pump or exhaust scavenging system or something along those lines. My point is unless you are building a high power street machine or a racecar, a pcv system is a simple solution that works. Link to comment Share on other sites More sharing options...
importwarrior Posted June 24, 2015 Report Share Posted June 24, 2015 http://www.dsmtuners...-system.366890/ just minimize the ads in the pics but good info on catch can setups with or with out the PCV. Link to comment Share on other sites More sharing options...
speedyquest Posted June 24, 2015 Author Report Share Posted June 24, 2015 @JohnnyWadd - I'm definitely going to do some research on venturi effect, that stuff never entered my thoughts on it. I also see your point about the improving the existing system. It goes hand in hand with what ucw458 is saying. @ucw458 - I think you and JohnnyWadd are right, and its pretty evident that the two of you don't see any decent benefit from removing the pcv system. @importwarrior - Thats a great link, its one of the ones I read though while I was researching how to set my ventilation system up. I will say I read a lot of misleading and even completely false information on different places. I think that link covers most of the bases pretty well. I think you guys have convinced me that keeping the pcv system, at least for now anyway, is the way to go. I can always modify it later if I feel like it. I will have some pictures of the catch can and stuff in my build thread later so you can see what kind of catch can I bought. Its a sealed unit with two ports (in, out), has baffles, has a portion of the baffling meant to put some kind of filtering media in it if you want, and has a "dipstick" for checking the oil level inside. I've kind of made up my mind on my setup but that doesn't mean we have to stop talking about this, feel free to comment or hell talk about your setup. Link to comment Share on other sites More sharing options...
polarisman14 Posted June 24, 2015 Report Share Posted June 24, 2015 I would suggest putting steel wool or something similar inside of it--definitely helps keep the oily mist from re-entering the engine. Link to comment Share on other sites More sharing options...
speedyquest Posted June 24, 2015 Author Report Share Posted June 24, 2015 (edited) Yea the steel wool is definitely something I plan on doing. The catch can I got has a spot for you to add your own filter media so that is very nice. But one note, you definitely want to use something stainless and not just regular steel wool. Edited June 24, 2015 by speedyquest Link to comment Share on other sites More sharing options...
Fuze Posted June 24, 2015 Report Share Posted June 24, 2015 I'll split the difference, I run an after market separator can in the stock configuration but without the oil drain line. On the intake side I use a medium Krank Vent and replaced the PCV with a brass nipple that's about 3/8 inside, (no restriction like the tiny stock PCV) with a 3/8 line to the intake with the KV in between. The motor creates enough vacuum to suck the dipstick out of your hand and pull it back down. I've tried other setups but this one works great. The KrankVent is just a big check valve like the one connected to the brake booster. Link to comment Share on other sites More sharing options...
speedyquest Posted June 24, 2015 Author Report Share Posted June 24, 2015 (edited) Are KrankVents still available? EDIT: Yep I found the website - http://www.et-perfor...&products_id=98 My big concern with making that part of the ventilation system even more efficient is the motor pulling even more un-metered air past my MAF. Edited June 24, 2015 by speedyquest Link to comment Share on other sites More sharing options...
importwarrior Posted June 24, 2015 Report Share Posted June 24, 2015 https://www.radiumauto.com/Universal-Oil-Catch-Cans-C58.aspx My favorite site for catch cans. Link to comment Share on other sites More sharing options...
speedyquest Posted June 24, 2015 Author Report Share Posted June 24, 2015 I'll post a picture of the catch can I chose so you guys can see it. I'll be installing it tonight. Link to comment Share on other sites More sharing options...
speedyquest Posted June 25, 2015 Author Report Share Posted June 25, 2015 Here is the catch can I got. It is $90 shipped on ebay and it comes with some very nice hose clamps and some "ok" hose. http://i.imgur.com/8Sk1nGB.jpg http://i.imgur.com/zPs61zQ.jpg Check out my build thread, I'll post a a few more pictures over there just so I'm not spamming pictures all over. Link to comment Share on other sites More sharing options...
Fuze Posted June 26, 2015 Report Share Posted June 26, 2015 (edited) My big concern with making that part of the ventilation system even more efficient is the motor pulling even more un-metered air past my MAF. With the oil drain port on the oil-pan plugged, I don't run any breathers so there isn't anyplace for air to enter after the MAF sensor besides out of the separator can. That is the stock setup though, it's meant to work that way with the captive air in the crankcase recirculating. With less restriction, it just circulates better. The inside of the motor is under heavy vacuum off boost, and on boost the Krank Vent snaps closed while the rear line evacuates blow-by better. No popped dipsticks after boosting hard. Edited June 26, 2015 by Fuze Link to comment Share on other sites More sharing options...
Funky Phil Posted June 26, 2015 Report Share Posted June 26, 2015 Id put some mesh in there speedy. Link to comment Share on other sites More sharing options...
speedyquest Posted June 28, 2015 Author Report Share Posted June 28, 2015 Yep that is what I did. I got some stainless steel wool, the coarse stuff, and filled that section. That is what its for. Link to comment Share on other sites More sharing options...
mstieg Posted July 8, 2015 Report Share Posted July 8, 2015 (edited) I posted a similar question not too long ago and was advised to make use of a BMW X5 separator. The holes in the mounting bracket are in the same place so relocating it is no big deal and the inlet/outlet lines (and drainback to the pan, less of a concern) are a larger diameter so those of us running MPI or higher than stock boost levels need not worry. I'm going with the X5 after researching this up a bit too:Phil's got his head on straight: http://www.sqperform....php?topic=92.0 Separator thread: http://www.starquest...ic=144231&st=20 More on Separators: http://www.starquest...pic=142119&st=0 For a stock setup using the MAS or MAF you can avoid the trouble of unmetered air and the limitations of the intake vacc not helping under boost by eliminating the PCV and turbo intake by using a new source of vacc....the exhaust. Many cars have been doing that for years. Get a good one-way valve and install onto the exhaust, use an adjustable valve by the oil separator to set a limit the max vacc. I've got the rear and PVC ports connected and running to the X5 to pull from case. Use whatever separator you like, but the X5 is cheap and has big flow needed for mine. No turbo connection, no intake connection. Almost done and will post pics then. Edited July 8, 2015 by mstieg Link to comment Share on other sites More sharing options...
importwarrior Posted July 8, 2015 Report Share Posted July 8, 2015 get one of these and you can drain and or flush out the can when ever you like... the good thing is you cn route the drain hose where ever you like for easy access. Link to comment Share on other sites More sharing options...
polarisman14 Posted July 16, 2015 Report Share Posted July 16, 2015 Would one of you guys with the x5 separator mind measuring the upper inlet/outlet for me? I gotta order some silicone hose for it and I don't have it right in front of me, can't find the diameter online anywhere. Thanks. Link to comment Share on other sites More sharing options...
lionbull Posted July 16, 2015 Report Share Posted July 16, 2015 have you seen these?http://www.starquestclub.com/forum/index.php?showtopic=147944 Link to comment Share on other sites More sharing options...
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