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Thread: Crank Case Ventilation fully explained. (Naturally aspirated edition.)

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Posts: 151-160 of 165
2012-10-11 07:50:09
#151
awesome thread. i am having dipstick issue since i turbod my ve last week..has the turbo edition started, is there a link?

found it,,
Last edited by pedro666 on 2012-10-11 at 07-57-04.
2012-10-11 11:20:26
#152
I added a breather and capped my intake and oil started to come out of my worn oil dipstick, on high boost. So I used heat shrink on top of the part of the dipstick thats supposed to seal, and its now tigth and snug and it wont come out under boost.
2015-01-30 18:37:45
#153
Originally Posted by SGTSR20
I added a breather and capped my intake and oil started to come out of my worn oil dipstick, on high boost. So I used heat shrink on top of the part of the dipstick thats supposed to seal, and its now tigth and snug and it wont come out under boost.


Hey, for those who wonder about boosted.
I know this is a posting in a ooooold thread kinda deal.
I came here through google, Read all of the posts, lots of useful stuff

My experience:
SR20DET Blacktop vvt S14 , 250 000 km on the odo, 350 Whp.
trackdays (engine runtime of about 6 hours on the track in a day) daily driving to work and there was really no issues with oil breathing out excessively.
I Finally NOW! understood what the passages was doing, I hooked up crank to the stock place (right above) with a T then to a catchtank, then the front breather to the catch, PVC valve straight to the intake.
Amount of oil in the turbo compressor inlet, a bit yucky kind of oil, catchtank, almost nothing, what was there was veery sticky.
Was a custom Large catchtank, side entrances for breathing, two AN10 hoses, inside with a condensation plate.
My experience is primarily this, but the engine before doing things I did not know I had it as stock and didn't have any issues (same engine)

So, there's not a lot of stuff coming out of it at all,
But I was questioning the need for the clunky catchtank with the VE valve cover, because I am now building a new engine with a P12 VE head on the sr20 rwd block, anyways.
The oil breathing will be more excessive than you'd need it to be if you run a T split where I ran it you actually defeat the purpose of the internal valve cover design, at least on the VE valve cover for the P12, going to assume for now the DET is the same.
you should only have two exits on the valve covers for the optimum setup.
I've attached a photo of it, sorry it looks a bit iffy,
you run your normal valve to the intake manifold on N/A and Turbo, the one that is at the rear on VE valve covers to intake prior to throttlebody on N/A or just prior to the turbo on turbocars, on VVT DET covers it's the exhaust side output that is the foremost of the two.
the exhaust side port on the VE cover to crankcase, on VVT DET it's the exhaust side that aligns with cylinder 4.
VE valve cover picture:


I took a remote camera and looked inside the passages, and it got a lot of condensation plates, so to me, if you get blowby, it must be something wrong with your engine on a DET VVT and a VE P12, because they really well made.

I'll see if I can verify the DET VVT head today, also should have a cover for a old highport DE somewhere.
2015-02-17 02:36:51
#154
@BenFenner what is the best option for sr20ve crank case ventilation
2015-02-17 12:34:01
#155
Same as any other engine. Dry sump oiling setup.
2015-02-17 22:20:57
#156
@BenFenner dry sump is out of the budget any other sugestion?
2015-02-17 23:16:36
#157
vacuum pumps
2015-02-17 23:55:06
#158
The thread has suggestions in order of their effectiveness. Can't handle the most effective, go back one method and see if you want to do that method. Keep moving back until you find one you're comfortable with. Pros and cons are all spelled out. The VE valve cover is a little bit different, but that difference is explained in the thread. Once you're familiar with how it works, you'll know what to do. Which sadly will involve turning on that big brain of yours.

Personally, I can't do dry sump either, and I can't do mechanical vacuum pumps, and I've not found good electric vacuum pumps, so I go all the way back to the exhaust scavenging method as my preferred method because I don't have a catalytic converter. Sweat the details and get it right and you're good to go. If you do have a catalytic converter then maybe just leave the damn system stock. It's quite good stock, especially if you're not turbocharged. Why anyone fucks with a stock VE CCV system is beyond me.
Last edited by BenFenner on 2015-02-18 at 00-03-14.
2015-02-18 01:24:13
#159
Originally Posted by BenFenner
The thread has suggestions in order of their effectiveness. Can't handle the most effective, go back one method and see if you want to do that method. Keep moving back until you find one you're comfortable with. Pros and cons are all spelled out. The VE valve cover is a little bit different, but that difference is explained in the thread. Once you're familiar with how it works, you'll know what to do. Which sadly will involve turning on that big brain of yours.

Personally, I can't do dry sump either, and I can't do mechanical vacuum pumps, and I've not found good electric vacuum pumps, so I go all the way back to the exhaust scavenging method as my preferred method because I don't have a catalytic converter. Sweat the details and get it right and you're good to go. If you do have a catalytic converter then maybe just leave the damn system stock. It's quite good stock, especially if you're not turbocharged. Why anyone fucks with a stock VE CCV system is beyond me.


i just try.....but my catalytic converter is out
2015-08-03 19:39:00
#160
Originally Posted by BenFenner

Here is another diagram showing the normal operation of the crank case ventilation system with half of the system greyed out:



That pathway is used around 90% of the time you drive the car. A little blow-by is pushed into the crank case but the intake manifold sucks it up and the oil separator in the valve cover keeps most of the oil from escaping the engine. The manifold keeps a good vacuum on the crank case during idle and partial throttle conditions which amount to most of your driving.


I've been dwelling more into this again, especially with how blow-by happy Subaru's are and found something I didn't think about before and that's incorrectly portrayed here.

Here is the diagram from FSM for 1999 SE-L


Basically when the PCV valve is open and the RPM's are low enough, fresh air enters through the intake's VC breather and oil separator, that fresh air helps displace out the contaminated air to the PCV valve to be sucked into the intake manifold.

Thus it's incorrect to just gray out this section and should actually have blue lines going down through the oil separator into the crank.
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