L61 Supercharged PCV - Boost Forum

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L61 Supercharged PCV
Tuesday, August 07, 2012 11:56 AM
So I have succomb to the need for a catch can, and a vented one at that. Can you guys point me in the right direction for a decent inexpensive one with dual ins and a single out. I am thinking I am going to go from the LSJ VC nipple and the oil cap port TO the can, and draw a vaccum through the brake booster line which will always be under vaccum from the blower.




Re: L61 Supercharged PCV
Tuesday, August 07, 2012 5:02 PM
From what ive read on CSS you want one or the other.

Runt it vented or a closed system. Some guys were saying to block the pcv port in the head under the intake manifold and run a baffled catch can to the intake tract.

Im not sure why you would want to block the pcv port though. But it makes sense why you don't want it vented to atmosphere cause then it wouldn't pull a vacuum at speed.

This is a catch can I read about that is a decent price
http://www.saikoumichi.com/

And Moroso makes a nice baffled can.
http://www.jegs.com/i/Moroso/710/85497/10002/-1?CT=999
Re: L61 Supercharged PCV
Tuesday, August 07, 2012 5:49 PM
So I have been doing alot alot alot alot of reading on this subject.

I have come to the conclusion that the port in the head that we cut our manifold gasket for is not needed. If we plug or cap this port somehow, and move our vaccum source from pre TB to post TB, and run a catch can, we should be able to see enough vac to evac the system properly.

So basically, go from the VC nipple to a catch can NON VENTED, to the brake booster line, all should be well...what does everyone think?



Re: L61 Supercharged PCV
Tuesday, August 07, 2012 6:43 PM
Bingo....

Thats what ive come to the conclusion of as well.

Although im not sure of the reasoning yet of blocking the port just yet.....any links to the reasoning?
Re: L61 Supercharged PCV
Tuesday, August 07, 2012 6:54 PM
Philly, that port in the l61 head works with the stock manifold to let the vaccum created by driving pull crankcase gasses from the case. While us boosted guys are just cruising, it is doing the same thing for us (if you cut you manifold gasket). BUT if you are boosting, and the "check valve" that some say is built into the LSJ manifold is bad, you are essentially pressurizing your crankcase "on purpose". Which will cause issues. Basically you are reversing the system. So if we block off that hole in the head, it doesnt allow us to pressurize the system any longer. Now you will have to run a catch canned line from the valve cover nipple to a spot POST THROTTLE BODY that see vaccum and evac the system that way.


no i could be 100000% bass ackwards on this, and if i am i need someone else to chime in and let me know. but i have blown 2 rear main seals in 7 weeks, and the ONLY reason i can see for this is too much crankcase pressure and i am positively pressuring the case accidently on purpose. to me this mean the "orfice" or "check valve" that is supposedly built into the LSJ manifold is bad.



Re: L61 Supercharged PCV
Tuesday, August 07, 2012 8:29 PM
EvoFire wrote:

Philly, that port in the l61 head works with the stock manifold to let the vaccum created by driving pull crankcase gasses from the case. While us boosted guys are just cruising, it is doing the same thing for us (if you cut you manifold gasket). BUT if you are boosting, and the "check valve" that some say is built into the LSJ manifold is bad, you are essentially pressurizing your crankcase "on purpose". Which will cause issues. Basically you are reversing the system. So if we block off that hole in the head, it doesnt allow us to pressurize the system any longer. Now you will have to run a catch canned line from the valve cover nipple to a spot POST THROTTLE BODY that see vaccum and evac the system that way.


no i could be 100000% bass ackwards on this, and if i am i need someone else to chime in and let me know. but i have blown 2 rear main seals in 7 weeks, and the ONLY reason i can see for this is too much crankcase pressure and i am positively pressuring the case accidently on purpose. to me this mean the "orfice" or "check valve" that is supposedly built into the LSJ manifold is bad.


That Makes sence. I wish I was able to see this check valve. Easiest way to block it off would be using a new intake mani gasket, but might as well do the phenolic spacer while your at it.

I cant see why it would make a difference though if your post or pre tb. Either way your going to pull vacuum upon acceleration.
Re: L61 Supercharged PCV
Wednesday, August 08, 2012 6:41 AM
That has been my recommendation for a while now. Block the port in the head with a new gasket and then add as many ports as you can to the crank case and valve cover and run them to a baffled catch can and then to a good vac ONLY source. Running it to the manifold with a check valve is well and good but at that point it closes up during boost which is when you need it most.

I have setup a dual check valve setup as the manifold will see more vaccum at idle and cruise and then shut while another opens at boost but to be honest it's complicated and really not needed unless you're into really high boost, I only know of 2 members that required it and the system worked.

I would love it if somebody like PJ could confirm the check valve that apparently is in the head on an eco. On the LD9 it's just a port down to the air/oil separator.

-Chris-



-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
Re: L61 Supercharged PCV
Wednesday, August 08, 2012 11:38 AM
Subscribed. I've been wondering about this recently too. Mine is still setup the way the GM kit has it; VC nipple to a grommet in the intake pipe before the TB. I assume that also means I'm blowing excessive pressure into the crank case...


"In Oldskool we trust"
Re: L61 Supercharged PCV
Wednesday, August 08, 2012 5:18 PM
No you wont blow anything into the crank case as long as the check valve is working correctly. The only time youll be blowing pressure into the crank case is if it has failed.

When I do my phenolic spacer im going to get it from ZZP and it covers the pcv hole. Problem solved.
Re: L61 Supercharged PCV
Wednesday, August 08, 2012 6:21 PM
So maybe I read this information wrong then. Minus some oil and residue in my intake tube, what's wrong with the stock/gm s/c kits pcv setup?


"In Oldskool we trust"
Re: L61 Supercharged PCV
Wednesday, August 08, 2012 6:26 PM
Ryan Pitt wrote:

So maybe I read this information wrong then. Minus some oil and residue in my intake tube, what's wrong with the stock/gm s/c kits pcv setup?


if it is functioning 100% correctly nothing. However most guys here dont have a setup that functions properly due to age and a bad "check valve" or "orfice" There is an orfice supposedly built into the lsj manifold that lets air come out of the head, but doesnt let it go back in. If that orfice is functioning right then you are fine. if it is not, then when you boost you are pressurizing your crankcase which is bad.




Re: L61 Supercharged PCV
Wednesday, August 08, 2012 6:42 PM
Interesting. Thanks for clearing that up. And the only way to check is to pull the manifold off and test?


"In Oldskool we trust"
Re: L61 Supercharged PCV
Wednesday, August 08, 2012 6:49 PM
yes, which at that point you might as well plug/cover the hole anyways!



Re: L61 Supercharged PCV
Wednesday, August 08, 2012 6:52 PM
Word. And install a spacer!


"In Oldskool we trust"
Re: L61 Supercharged PCV
Wednesday, August 08, 2012 8:14 PM
Only time i had a problem with pressurezing my crankcase was when i ran too small of hose to my catch can. I was spitting oil out my dipstick tube. Went to bigger hose and havent had a problem since.


black 03 z24 with a few mods
Re: L61 Supercharged PCV
Thursday, August 09, 2012 3:20 AM
I run one line from my valve cover to my catch can. A line from the PCV to my catch can, and a line from the catch can to the turbo intake. My catch can fills up quite a bit but to me seems like its working...


Re: L61 Supercharged PCV
Friday, August 10, 2012 3:46 PM
do you have any of those valve laying around vince? i read the thread where you ordered them from, or can you get me a link to them? my dad has a MCM account.



Re: L61 Supercharged PCV
Monday, August 13, 2012 5:17 PM
Just run it like I said and be done with it.



ASE Master Certified Automotive Technician

Re: L61 Supercharged PCV
Monday, August 13, 2012 5:18 PM
yeah i know thats the plan. looking for a decent can now.



Re: L61 Supercharged PCV
Thursday, August 23, 2012 11:39 PM
Has anyone ever thought of tapping the stock MAP spot on the neck of the blower, and running a line to there to pull vaccum...of course a line coming from a catch can?



Re: L61 Supercharged PCV
Friday, August 24, 2012 1:31 AM
EvoFire wrote:

Has anyone ever thought of tapping the stock MAP spot on the neck of the blower, and running a line to there to pull vaccum...of course a line coming from a catch can?


Thought had crossed my mind to do that...you should be seeing the same vac there that you would when running a tee from the brake booster hose. Just make sure your catch can is a good baffled one, don't wanna be sucking that blow by right into the s/c rotors.
I had excessive build up prior to a good catch can system...I had a cheap eBay can between the valve cover nipple and intake. My throttle body had all sorts of blow by in it, and I'd occasionally get blow by pushing the hose on the vc which lead me to believe I'd be blowing a deal shortly.
Upgrade to two 8an lines off the valve cover (also modified vc baffling internally), into a good baffled can, and pull vacuum of my air inlet pipe (with a check valve in this line). Problem solved. Seems to be working for me, though I may move my inlet line to post tb just for piece of mind since.

Just watch if you do decide to run a line from the map hole on the blower...with the spacer on the blower you're gonna be running close on hood clearance.







Re: L61 Supercharged PCV
Friday, August 24, 2012 6:11 AM
Quote:


Just watch if you do decide to run a line from the map hole on the blower...with the spacer on the blower you're gonna be running close on hood clearance.


This would be my biggest concern. Even without a spacer it would be close to pinch the hose, unless you have a anlged adapter/conncector on the tope of the charger.



FU Tuning



Re: L61 Supercharged PCV
Friday, August 24, 2012 11:51 AM
My thought was to drill and tap for a -6 or -8, and run an adaptor or series of adaptors do bring it down infront of the blower, and then run back to a catch can on the fire wall or hidden somewhere. I want to run a catch can that would have 2 ins and one out, and run the VC nipple, and one other area to it. I was thinking about the Metco oil cap adaptor.


My dad seems to think that there needs to be a place for air to be introduced to the system. I am not sure what to think about that. isnt the purpose to have the crankcase under vacuum.


Here is what my dad and i were thinking....

plug/bloke the hole in the head, and run a line from the valve cover to a catch can, then from another fitting to the catch can, then from the catch can to the blower. then have the filter cap on the oil cap spot.

this whole PCV thing confuses me. the more i think i understand, the more confused i actually am.



Re: L61 Supercharged PCV
Friday, August 24, 2012 4:45 PM
From my reading you want either or...

A sealed or vented system.
Re: L61 Supercharged PCV
Sunday, September 16, 2012 2:54 PM
Your dad knows what he's talking about.



13.3 @ 106 mph Cammed
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