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

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Posts: 101-110 of 165
2011-04-18 16:42:30
#101
Thanks Vadim. Can you or someone else "OK" the turbo edition that I've submitted? I know it's just a shell, but the best way to get me to finish it is to start it and get it out there. I need the first 5 posts to be mine as well.
2011-04-18 17:09:48
#102
Originally Posted by BenFenner
Thanks Vadim. Can you or someone else "OK" the turbo edition that I've submitted? I know it's just a shell, but the best way to get me to finish it is to start it and get it out there. I need the first 5 posts to be mine as well.


Yup done deal too .
2011-04-18 17:38:53
#103
BTW, the PCV valve is the biggest HP upgrade you can do. The sr20 suffers from huge restrictions from the PCV valve. When replacing it with this highly tuned part, you get NASCAR performance out of the sr20!

2011-04-18 18:48:41
#104
How are you hooking it up?
2011-04-18 19:08:18
#105
Originally Posted by unijabnx2000
How are you hooking it up?


Well, I think I have it backwards. So far, it works like a normal PCV valve.
2011-04-18 19:13:23
#106
phixer, I'm not sure your enthusiastic sarcasm is going to go over well in this technical thread. =/

Worse yet, other people might actually believe you.

I'd maybe recommend you start a new thread if you want to be humorous.
2011-04-18 20:55:15
#107
Originally Posted by BenFenner
phixer, I'm not sure your enthusiastic sarcasm is going to go over well in this technical thread. =/

Worse yet, other people might actually believe you.

I'd maybe recommend you start a new thread if you want to be humorous.


Public spanking duly noted. :o
2011-04-18 20:56:08
#108
Enjoy your NASCAR performance.
2011-06-17 13:13:10
#109
I discovered a detail in the PCV system that I left out of my diagrams (and I had no idea it existed until now).

The small OEM emissions hose that connects the PCV valve to the intake plenum has a restrictor in it as well. The opening is quite small, maybe 1.5mm or so. I will have pictures in a bit, and will update the diagrams to reflect this soon.

I believe the restrictor is there for the same reason the other restrictor is there, to prevent a run-away idle situation where air is brought into the plenum through the valve cover from the intake pipe (by-passing the throttle body in a convoluted pathway during high vacuum situations).

The restrictors themselves seem counter productive to me when you think about the kind of flow you want in a PCV system. I've removed the restrictor in the WOT section on my engine with no ill effects to idle that I can tell. That might be the case only because I still have this other restrictor in place. I'd be very curious to see what would happen if this other restrictor is removed, and I might try that on my engine. I also wonder about those out there who have replaced this hose with one without a restrictor not knowing that it was there to begin with. I wonder if they have experienced high idle issues or problems with too much vacuum in the crankcase.

I'm just glad that when I replaced my cracked PCV hose I insisted on getting a new OEM one. Otherwise I'd never have known it was there.

Images of this restrictor can be found in this album.
Last edited by BenFenner on 2020-08-19 at 08-48-43.
2011-06-17 16:56:55
#110
I also apparently need to add this kick-ass PDF to the first post.
It was written by “Digsy” for Vortex-Power.co.uk and MKIVSupra.net in August of 2005.
Tons of great info in here which basically mirrors my explanation but goes a step further by going into volume of flow and other stuff. At least look through it real quick. Once you do you'll realize you should read it too.

http://www.106rallye.co.uk/members/dynofiend/breathersystems.pdf
Last edited by BenFenner on 2011-06-22 at 20-06-32.
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