cygnusx1 Posted April 8, 2007 Share Posted April 8, 2007 I am in the process of tearing down my fuel system and intake system for the new injectors, rail, MS-II and new air intake. I had the crank case vent connected to the intake through the stock PCV valve and the valve cover vented into the intake tube before the turbo. Now that I am going MSII with MAP sensing, would it be ok to connect the valve cover and the crank case vent to a catch can that has a filter to atmosphere? Could I just plug up the old PCV valve hole in the manifold? If so, does anyone have any ideas or photos of how this can be done to look clean in the engine bay? I could also just put small filters on the Crank vent and valve cover vent and forget PVC and a catch can. No? Any thoughts ideas appreciated. I tried searching but I came across some dead end links. I did read about the benefits of having vacuum in the crank case though. Quote Link to comment Share on other sites More sharing options...
1FASTKINGCAB Posted April 8, 2007 Share Posted April 8, 2007 I did the mini filters once, if you run alot of boost OR have alot of blow by they will get oily and collect ALOT of dust. I ended up geting a catch can. and just plug the manifold. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted April 8, 2007 Author Share Posted April 8, 2007 Did you connect both vents to the can? Quote Link to comment Share on other sites More sharing options...
NCchris Posted April 8, 2007 Share Posted April 8, 2007 A good read about PCV systems and boosted applications http://honda-tech.com/zerothread?id=1199935 HTH chris Quote Link to comment Share on other sites More sharing options...
naviathan Posted April 8, 2007 Share Posted April 8, 2007 Don't disconnect your PCV. It's there for a reason. How long do you want your engine to last? You might get a couple years out of it without the PCV, but then you're looking at replacing everything internally. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted April 8, 2007 Author Share Posted April 8, 2007 Naviathan, care to explain? NCchris, I read the Hondatech post. Very nice info. It looks like I may go with a slashcut tube in my downpipe to generate vacuum. I suppose I will connect the valve-cover vent and crankcase vents to a sealed catchcan and then run a single hose with check valve to my vacuum generator tube in the downpipe. The intake manifold PCV port will be plugged. The vacuum from the slash cut tube, will draw blow-by gasses into the catch can where the liquids will settle and the smoky stuff will continue into the downpipe, six inches downstream of the O2 sensor. Sound right? This should keep the intake nice and clean and create a vacuum in the crankcase under loads. The smoke will go out the tailpipe and the solid contaminents will be stored in the catch can for draining later. Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted April 8, 2007 Share Posted April 8, 2007 There is a ton of info over on ls1tech.com about PCV catch cans. A known problem on LS motors. Soem sample type set ups Lots of talk about breathers vs a PCV system. Also Moroso sells an evac system that uses exhaust flow to draw a vacuum in the engine and burns off any excess oil in the exhaust. Just make sure whatever you use has some type of filter in it. I can't find the link but some guys on ls1tech.com sell some really nice aluminum cans that look really sweet. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted April 8, 2007 Author Share Posted April 8, 2007 If you are trying to generated vacuum in the catch can with a slash cut tube in the exhaust, I dont think you want the catch can open to a filter otherwise the vacuum is lost. Hmmm. This is a much deeper subject than first appears. Quote Link to comment Share on other sites More sharing options...
NCchris Posted April 8, 2007 Share Posted April 8, 2007 If you are trying to generated vacuum in the catch can with a slash cut tube in the exhaust, I dont think you want the catch can open to a filter otherwise the vacuum is lost. Hmmm. This is a much deeper subject than first appears. There was another post that I couldn't find but the essence is to use a filter on the valvecover, plumb the existing PCV collection point on the drivers side front of the motor to the catch can. PCV/check valve in the top of the catch can routed to vacuum scource. (slash cut in turbo inlet or exhaust) FWIW, oily residue in the intake track will somewhat lower deatonation threshold in a boosted engine. Ref. theoldone.com (Endyn) HTH chris I have a sketch on my hardrive at home. I will post when I get home tonite. Quote Link to comment Share on other sites More sharing options...
NCchris Posted April 8, 2007 Share Posted April 8, 2007 On second (third or so) thought, why even use a can if you are routing to the exhaust? The reason for the can is to keep the oily residue out of the intake tract. If you are running a cat, you might run into problems with oil in the cat.........but........questions, questions...... chris Quote Link to comment Share on other sites More sharing options...
naviathan Posted April 8, 2007 Share Posted April 8, 2007 Naviathan, care to explain?NCchris, I read the Hondatech post. Very nice info. It looks like I may go with a slashcut tube in my downpipe to generate vacuum. I suppose I will connect the valve-cover vent and crankcase vents to a sealed catchcan and then run a single hose with check valve to my vacuum generator tube in the downpipe. The intake manifold PCV port will be plugged. The vacuum from the slash cut tube, will draw blow-by gasses into the catch can where the liquids will settle and the smoky stuff will continue into the downpipe, six inches downstream of the O2 sensor. Sound right? This should keep the intake nice and clean and create a vacuum in the crankcase under loads. The smoke will go out the tailpipe and the solid contaminents will be stored in the catch can for draining later. The PCV system is designed to evacuate acidic gasses and vapors out of the crankcase. Without some kind of draw (as has been covered in the later posts here i.e. vacuum) to pull it out the gasses will mostly stay put, just running a little filter won't cut it. Those gasses if left in the engine will contaminate the oil very quickly and produce all kinds of deposits and eat away at the internal components of your engine. You'll end up with pitted bearings, quickly worn seals, misshapen oil galleries and just all around havoc in the engine. Gotta get the acidic garbage out as efficiently as possible. Quote Link to comment Share on other sites More sharing options...
Cody 82 ZXT Posted April 8, 2007 Share Posted April 8, 2007 take a look at how I did mine. Seems to work well. I only had it like this for about 2 months before I put the car into paint jail. http://www.angelfire.com/space/nismo1turbo/indexengineinstall.html Quote Link to comment Share on other sites More sharing options...
rztmartini Posted April 9, 2007 Share Posted April 9, 2007 one thing you might want to watch out for, I read somewhere that those venturi-action systems draw a LOT of vaccum. you might want to run a restrictor on the line. that much of a vaccum in your block and/or valvecover might not be good. my $0.02 Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted April 9, 2007 Author Share Posted April 9, 2007 Naviathan, thanks for that info. Sounds like nasty stuff! Cody 82 ZXT, nice setup, where are you making vacuum for the catch can? Is it the push-lock tube on the side of the can? Where does it tie in to the motor? Quote Link to comment Share on other sites More sharing options...
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