I have heard that I should eliminate the PCV system on my B18 since I am turboing it. So I was wondering… Should I just run a catch can instead of the pcv system on the motor? If so where should I hook up the lines for the catch can? Any help is appreciated. I am not looking foward to blowing oil on my daily driver ;D
Depends on the PCV. I replaced mine with KrankVents (Do a google search for them) as the stock ones were inadequate for the pressure I was building.
Consider little K&N filters or a catch can.
Yea I was going to run thje catch can off the VC and off a gutted pcv valve. That way it would let out any pressure that was built up from boost.
Just wanted to make sure this was a logical way of doing it.
boxersix knows a lot about catchcan setups. Im sure he could help you out a lot.
The PCV system is not there to vent pressure but to evac the crankcase from blow by carbonates that contaminate the oil. W/O a working pcv system, or a vac pump system, you oil will lose it’s properties to keep the motor well lubed AND clean. System must have a fresh air entry to work properly, and a vac source to draw the fumes and contaminates out.
I’m quoting this from myself on another forum where we discussed an exhaust PCV system, Ryan is my buddy in FL with another Holset turbocharged avenger. I’m JadedSilver for reference if mentioned
Ryan…here is the proper way to setup a PCV system into a catch can on a turbocharged car. The proper way actually requires two catch cans(or a custom split tank unit icon_wink.gif )
Intake pre turbo ----> Catch can ----> Large 1/2" check valve(flow direction to valve cover) ----> Valve cover breather port
Then
PCV port ----> Catch can ----> Large 1/2" check valve(flow direction towards plenum) or OEM PCV valve ---->Plenum
Obviously lines connect those parts. Vacuum in between the turbocharger and filter is very small, about 1-2 HG when the filter is clean. dirty filter will increase this a bit. No filter will drop it quite a bit. Port placement in the intake track isn’t a huge deal, but I’d try to keep it around 12" from the turbo inducer if possible. The PCV system ONLY work under extreme vacuum, like at idle or decel as stated…
Just as you were getting to, the PCV system works by drawing in air via the intake track down into the crankcase, and then back up into the plenum during states of vacuum(idle or decceleration) to purge the crankcase of blow by that can contaminate oil. It’s a continuous circuit, so looping or doubling up both lines back to a single closed CC doesn’t let the system work effectively.
The breather side catch can is not completely required but it does keep the oil out of the line that does build up in there. Catch cans don’t need to be huge(like those Summit things are) so you can easily fit two smaller units under the hood. Anything over 1/2 quart in size is just too big. If you’re motor is spewing out more crap than that then you have bigger engine problems to deal with…
Picture of what we’re talking about here next:
QUOTE(RyaN95i4 @ Mar 13 2008, 06:29 PM) *
i was hoping to get more feedback about the exhaust setups tho coughjaded, bc, etc cough
My feedback? Totally illegal, but completely my style. Proven to work based on properties of exhaust scavenging effect. I don’t do this myself as it’s not something I’ll do on a street car, and it’s usually illegal in most race organizations. Instant visual emissions failure if found, however I don’t believe that’s an issue for you down in good ol FL correct? Would I do it on my car? No, only because it’s not allowed under certain racing sanctions/classes at circuit tracks. Don’t feel like failing tech because if it that’s all…
Here’s a few tricks for you guys…
Keeping the check valves from melting…don’t run them directly off the pipe that’s all. The check valve(s) can go ANYWHERE in the system and actually the best spot for them is as far away from the header as possible. If you’re using a CC in the system, get a threaded valve and mount in in the can exit in place of the standard hose fitting that’s on there. Then run tubing to the exhaust. Best to keep them mounted about
Plum the PCV inlet into the exhaust as a reverse pitot tube. I won’t get into the explanation of why, but trust me on it…see simple picture I drew up…http://i123.photobucket.com/albums/o285/Boxxersix/pitot.jpg Outer box is exhaust pipe, red arrow exhaust flow, black bent line is PCV inlet to exhaust as a pitot tube…you don’t have to do this at all but it’s a better vacuum effect from it none the less.
If you’re running a WBO2 or any sort of o2 for that matter you must use a CC. The sludge will instantly destroy a sensor. The fumes also adjust the sensor readings a bit and will throw and tuning off as a result and the inlet should be mounted downstream of the WBO2. A catch can should just be used period. Blue smoke out the tailpipe is embarrassing no doubt ;D
Line size from exhaust…1/2 if no CC(to reduce clogging from coked oil at exhaust entrance), 5/16-3/8" if you run a CC. Lines to CC should be 1/2", again to reduce the chance of clogs, from foamed oil/water vapor in the this case.
Have at it 
Any questions feel free to ask. This is ALWAYS a commonly obscured topic on what the PCV system actually does and many people just disable it without thinking about it. It’s a VERY important system of a motor’s longevity.
The easy way to do it is the catch can. You could adapt the PCV system to work with boost but you get into alot of vacuum lines and check valves… It depends on how much boost you’re running and how much blow by you have. You probably don’t need a huge catch can system for your set up… summit racing has these for cheap summit racing breather tank
When I go to FI I’m keeping my PCV system for the reasons listed above
Another common misconception. Rather easy, see my post above.
Lowe’s or Home Depot has some oil separators for air compressors that work good in a PCV system. I would agree with Boxersix that it is better too keep it but people will tell you otherwise. There is a guy with a 9 second turbo LS1 that has a PCV system simmilar to what Boxersix posted and it works better then just venting your engine to atmosphere. Thats 1950s technology that you probably shouldnt use on a 1990s Honda.
No matter how the PCV system is setup, they all work the same. Draws in fresh air into the block from between the filter and TB, and extracts it into the plenum under vacuum when necessary. The exhaust system PCV setups have been widely used based on bernoullis principle when the exhaust flow over a pitot tube creates vacuum. It works on any car, but is 100% illegal as far as emissions are concerned
I set up one of those Homedepot specials on my 1.8t… But I vent the other side with a breather filter instead of sending it back into my intake, turbo inlet, intercooler…
I will suggest keeping it simple. I’m guessing at your power level here but a B18B turbo engine @ 250-300whp is not anything extreme, run a large barbed fitting from the valve cover to a catch can with a nice breather filter on top of it. Little to no crankcase pressure. Done…end of story.
…again venting pressure is only half of the PCV’s job…
I won’t dispute that, but I don’t think Eric’s application requires an elaborate system…just something simple and easy.
:confused Elaborate, that setup is far from elaborate. I guess the “do it right or don’t do it at all” mentality doesn’t apply to this forum.
Well you descibed two methods, which do you suggest? I would consider the exhaust setup elaborate because it requires more parts and a good amount of labor to do correctly. Its easy to show somebody else’s pictures but when it comes to actually making and installing it so that it functions perfect for the application…its a little different. Not that I need to tell you, but some engines/cars are hard to find room for all the plumbing, mounting the can, require extensive welding, fabricating brackets etc.
Believe me, the mentality of “doing it right” is not lost here. I totally agree with the methods you described and have no argument against what you said. But looking at the big picture, I don’t consider that practical for the majority of the guys on the street who are just looking to avoid popping the dipstick out or making clouds of smoke. In racecar fabrication there is enough money and interest to have optimal setups but unfortunately I have found most guys on the street just want something basic that performs well.
Agreed and I run into this quite often. The problem with most “street” people is that they do things that overall compromise something in a bad way, when in reality they need to find a good compromise between functionality and cost without doing something stupid(like sticking a breather filter on the VC fresh air inlet). These are the same people that have used ebay 14b’s welded to their stock manifold and slap a 12:1 RR FMU on their car and call it a good setup. In my line of work, sure I get the race guys that want a perfect setup despite the lines and components required. They’re worried about completing a 4+ hour enduro intact.
Relatively speaking the exhaust PCV system is not complicated at all and as long as o2 sensors and bung positions are setup in proper orientation they are versy simple(line with check valve to exhaust, line with check valve from intake with CC in between). I’ve yet to fin a car that I cannot fit a can somewhere under the bonnet and most of the time mount them off the transmission down low as you’ll be under the draining them when you change the oil as is. I like this system for it pure function and simplicity, however catch 22 if/when you need an inspection and catch flak for a fail visual on the system. Likely in this area? Probably not but still not something you’d want to revert back just to get a sticker in the window.
The other problem people run into is using cheaper(summit racing) catch cans that are not baffled. Without internal baffling to catch the oil and moisture vapors the system isn’t functioning properly and really is a waste of space under the bonnet like you mentioned.
Beleive me I understand you point here, I’ve just been around working in this field for so long and have seen so many bad shortcuts it makes me gag. A properly functioning PCV system on a motor is a very important component of a properly running drivetrain. Screw the emission part of it really, just plain good to the bottom end period(cleaner oil). Oxidized and carbonized oil is no good for you motor, the case pressure is the least of the concerns they should have. If these people are blowing dipsticks out of the tube on boost it’s because the motor is tired, or the OEM PCV setup is clogged/malfunctioning.
Just trying to keep the masses here informed of the right tech and not some hack crap that’s all 
Some of the higher hp cars with stock pcv systerms will blow out dipsticks although the engine itself is still very tight. Perfect example here is swift and mike. They both have stock pcv which is completely inadequate for their power levels and they both have blown the dipstick out before. On swifts engine the worst cyl had 1% leakdown. I hope both of them read this…its another reminder to do something that is long overdue. :lol
I would like to keep the PVC system as simple as I can be. But I want to to preform like it should. I have had several D-series motors that were turbo-ed. All off them started burning oil after a few hundred miles. I looked in to it more and read up on the PCV systems. I just wanted to prevent any damage to my rings and valve seals again. This was the most logical problem that I was having with the D’s.
The B18 I have has less then 40k on it and runs mint. I would like to keep it that way for a while. I am not looking to get as much power as possible from it. I just want to be able to run a consistant 6-8 psi daily, without any issues of burning oil.
Mine dipstick flew out and put a dent in the hood. Sprayed oil all over my face.
Putting on turbo on doesn’t really damage rings or valve seals. I’m betting the that the smokey engines were just classic old honda engines that were a bit tired. They tend to have issues with rings sticking, wearing and just poorly sealing against the cyl walls when they get old. The cylinders get a bit oval shaped too.