WJM and I have been discussing this a little. Thought I'd throw it out to the community to see if we get some more input. In stock form, the PCV breather plumbs back into the intake. This has the potential problem of putting oil in the intake. One common solution has been a catch can. However, once a catch can is full, the oil can go back into the intake. Also, I wouldn't want a lot of oil sitting in my catch can instead of in the oil pan. Better solution, Air-Oil Separator. Right now I don't have an AOS. My temporary catch can is a Dasani bottle with the breather tube going into it. When the car is idling, I can feel air pulsating out the breather. So I know that the PCV isn't stuck. However, under load, the stock system offers vacuum in the intake, that helps remove gases from the crank case. In my system, the PCV bleeds under crank pressure only as I am not offering any vacuum. 1) How big of a problem would this be? 2) How much vacuum is needed to effectively drain the excess crank pressure? 3) Does the vacuum help add more power as it pulls the pistons down? 4) Instead of the fancy gadgets, could I install a pump in line with the breather tube to constantly suck crank case gases out? Please feel free to add useful comments
Read through this a long time ago. I actually bought my 6 sp from the op and saw the setup on his car. He offered it to me for a reasonable price but I decided not to take it. Sounds like maybe I should have. http://forums.nasioc.com/forums/showthread.php?t=667007
This sounds interesting as I was going to replace my PCV to see if that helped with my oil consumption. Does anyone sell setups like this and if so, why does everyone else use a valve + catch can or separator?
Correct me if I am wrong, but if you can feel air pulsing out of the breather, then the PCV should be fine right? A stuck valve should be pouring out smoke from the tail pipe. What oil are you using? I will be switching to Shell Rotella T 5w-40
Run a check valve in the exhaust, thats the best system. Proven 1-3 hp gains. I drilled the front of the valve cover , ran it to a catch can. then I installed a 1 way check vavle into the exhaust AFTER the header to recirculate the blow by to the motor. You can get really trick an run a 90s Vette Smog pump to relieve crank case pressure But PCV is POSITIVE CRANK CASE VENTILATION. You should feel air coming out of the TUBE going to the PCV. If the PCV was clogged or stuck closed, then you would be seeing alot of blow by at lift throttle. If your PCV is stuck , then under extreme vacuum(LIFT THROTTLE), the motor sucks oil from wherever it can find it (head, valve stem seals, etc) an usually it gets by rings or out the exhaust. Rarely does a stuck PCV show smoke at idle or at WOT. the reason you get blow-by is because there is positive pressure in the bottom end. the motor is a sealed system so there are only two places for it to go: thru the tiny port on the back of the valve cover (into the intake), or past the rings. if you give it an easier way to get out (ie the big ports in the valve cover, attached to a catch can with a big hole in the top) it will take that path (ie "path of least resistance").
I believe it's a 10w30 motoule. My s2000 had no smoke but drank oil till i replaced the PCV on it so I don't believe there is always smoke. Several s2000 owners get 3rd party PCVs to fix oil consumption issues. This idea of using a pump is sounding more and more appealing. Does anyone make one or do you just have to piece it together?
Hondas are known for consuming oil, especially VTEC models. Usually, MOBIL 1 syn oil burns oil or consumes from what i have seen. ALso, late model hondas have had problems with oil control rings. Particularly late model 99-00 Civic SI, GSR and S2000s have had issues with oil burning PCV is RARELY the cause for oil consumption.
I dont know if plumbing into the exhaust on the subaru would be best...there tends to be more pressure there on turbo cars than N/A....unless you've seen it work on turbo Honda engines...Mike?
Fixed my issue in 01 s2000 w/ 79k miles. It would be wonderful if the same were true for my Legacy. Just need to get around to doing it.
A little OT but why Shell Rotella T? I agree with running a 40wt oil on the hot end but why that brand in particular? I like all these discussions on various oil breather setups.
I have run this method on Turbo motors with no issue, but never on a subaru. just trying to share info i know from other makes and models to compare with what people know to be true with Scoobys Its worked on V8s for YEARS BTW