crankcase/pcv evac system... ?
 

ok, so im broke, and cheap. just like everyone and their mom. so im not gonna shell out for a catch can, and even if i did, where the ---- is the vacuum to release the pressure? im just supposed to wait for the positive pressure to build up enough to the point that it releases itself??? this has to be the stupidest ------- thing ive ever heard of on a turbo car.

and i obviously cant afford some over priced dry sump vacuum bull ----. so next best thing??? slash cut. to the exhaust. ---- all that oil going back through my turbo, ic, and motor. i saw the kits on ebay and in jegs and summit for v8's with the breathers with the slash cut and one way check valves. i might pick one of those up just for the pipe and check valve. or i figure i could cut my own pipe, and get the check valve off of an old jeep, or even off of any brake booster, right?

but my next dilemma would be welding some baller ass 6 dollar AN fittings to my vc, and then getting 15 dollar 90* An fittings to connect that to a hose. ---- that. couldnt i just cheap out like half the people i see, and run the black box with no pcv? but instead of pointing that ---- at the ground for no apparent reason (oh, and i did this for a day... that was the dumbest ------- idea in the world. i got less blow by with my pcv hooked up, than i did with the black box wide just venting. stupid.) so how about instead of pointing the hose at the ground aimlessly and clueless, hook that bitch up to the downpipe, and draw all those fumes out when its needed most. under boost. ???? and i figure, i might even hook the pcv up to my vc, where i have that little breather filter, so i can draw the excess out by vacuum when im at idle...

does any of this sound like a good idea??? or should i go buy some stupid ass H-T baller ass set up, and pay some deusche bag to weld me up a catch can that's "custom fitted" to mount to my battery tray???

i need input. or ill just go hit the junk yard and home depot, and get on this ---- this weekend.

Re: crankcase/pcv evac system... ?
 

Just vent everything to the ground. 8)

Re: crankcase/pcv evac system... ?
 

my catch can is a 1pint used paint can with a cheap ass filter on it and a couple plastic nipples JB Welded in it. then the nipples off the back of the block... probably have 30bucks into it, only cuz the filter i wanted they raped me on :-\



but vented to the ground is a proven effective PCV ventilation technique :y

Re: crankcase/pcv evac system... ?
 

yea, i didnt exactly vent it to the ground. i left the hose from the black box running to the spot in between the IM runners, pulled the pcv out, and plugged the manifold side of the hose/vacuum. it smoked and started showing more drastic signs of blow by than before. like before, i would get some smoke, a little smell, but nothing major. but now everytime i pull the dipstick, it smells like fuel, the oil doesnt want to stick to the dip stick, and the car smokes if i dont hit boost (which i dont often, cus its my daily driver, boosts at 4k+, and i have a red license for another two months).

so i hooked the pcv back up, and it seems ok again, but i would still rather be venting the crank case more than it was designed for stock, obviously. so i want to create a vacuum. i cant really understand the whole open filter catch can thing, since youre not pulling positive crankcase pressure out, just giving it an escape. so its always positive, will never be negative or neutral.

so im pretty set on the slash cut exhaust thing, my dad uses it on his 73 chevelle, 540 bbc, 3700 lbs. runs 10.7s at altitude (5800ft). pretty sure if hes happy with it, i should be as well. he too tried the catch can thing, and said it was worthless. so im kinda going off of his experience. but since its not a chevy, i want to know why hondas dont do it more often (especially since its cheap), and what problems might i run into if i run the line from the black box to the downpipe/slash cut?

Re: crankcase/pcv evac system... ?
 

I agree the logic of a catch can is worthless if it's just attached to your block and vented via filter. I just don't get the point at all and a local guy making 500+ hp says he needs to add a 2nd one cause he still gets blowby. You're still just letting the blowby vent to atmosphere only you're filtering it before it leaves your car. :1

But open to atmosphere (pointed at ground or with vented catch can) is much better than stock pcv hooked back up. Yeah you'll put vac to the engine under low load/idle. But as you stated 'when you need it most' the pcv check valve will close under boost and any positive crankcase pressure will be trapped.

My logic says throw the stock pcv system in with another T and checkvalve going to the slashcut in your downpipe or exhaust. Then you'll have vac under low load/idle via the stock pcv at the intake, and under boost via slashcut. There are plenty of diagrams showing this

Pretty sure the moroso check vavle I saw in another thread looks exactly like the ones in the EGR system on old Chevys. I pulled a couple off of an 83 caprice that I threw away before I realized how usefull it could be. The slashcut looks self explainatory how to cut a nipple at an angle.

More people don't do it on hondas cause people need internets baller items instead of looking at how ---- works and what it does. The only problem with running a slashcut to the black box would come if you don't use a checkvalve. Low exhaust velocity will not pull vac but instead run exhaust into your block. Once ---- gets moving you should pull a nice vac. You can also get rid of that box and put a fitting directly on the block

Re: crankcase/pcv evac system... ?
 

there's the closest picture I found to what I would do. As you can see the two check vavles will supply a constant vac source but never allow you to pressurize the engine, and the catch-can is in line of the flow.

I'd probably experiment with doing what is in that drawing, and maybe putting an open to air filter where he labeled 'breather' on the valvecover instead of Ting it into the vac line. Depends on how much vac the slashcut pulls. The place labeled PCV location is the stock black box, if you run the check valves he has drawn you don't need a check valve at this location.

Re: crankcase/pcv evac system... ?
 

Why even transfer it back into the turbo/engine.


Take a quart of your current motor oil, take a hose from the valve cover, and a hose from a gutted pcv valve, cut two holes on the side of the bottle, shove the hoses in, slap a filter ontop, and shove it next to your battery, done!

Empty it, if it fills with ---- every time you change your oil, or when ever!

Re: crankcase/pcv evac system... ?
 

Did you read any of this thread?

Please tell me exactly what is the benefit of doing that over just leaving ---- wide open with the hose pointed at the ground?

You are doing nothing to help evacuate blowby from the engine, you are just catching what gets pushed out.

Re: crankcase/pcv evac system... ?
 

lol. thanks stenseltizm. thats exatcly what i was thinking.

as far as the diagram, i like it, but im cheap. lol. so im thinking the black box with act as an inline catch can, so i can run a tube straight to the slash cut, and definitely use a check valve, like the moroso and mr. gasket kits use. and then use the stock pcv just to make it sure its always got vacuum, even at idle. maybe later down the road, when i feel baller enough to waste money on AN fittings and a catch can, ill separate the pcv system and slash cut, and run a catch can inline of the slash cut, and let the black box and pcv operate as they were intended.

on another note. everyone says that they run the pcv pointed at the ground. would it be any different of an effect if you just left the hose running to the intake manifold, and disconnected the pcv from it, and plugged the IM vacuum, leaving you with a hose pointed at the hood, instead of the ground...

reason i ask, is i tried this method. first thing i noticed when i took it for a drive was smoke. i came to a stop, hadnt even hit boost yet, and i saw and smelt smoke blowing around my car. i think problem being, is that i dont hit boost until 4k or so. so i dont boost on a daily basis, or around town. usually on the highway or at the track. and occasionally a quick 1-2 pull. so during my normal daily, it needs that vacuum, since theres no boost to force the gases out.

by that night, it was still doing it, and i checked the oil. still level, so i knew it wasnt all of a sudden burning it, but it wasnt sticking to the dip stick very wel... gave it a whiff, yep. fuel in with my oil. and i had also noticed the oil was all the way up the stick when i first pulled it out. so from logic, i would say i was getting way more blow by than when i had the stock pcv hooked up. sound about right? well, i hooked the pcv back up, and left the cap off and dip stick out for a whole day to let the fuel try and evaporate out of my oil. problem hasnt seemed as intense since.

so for now, im leaving it this way. but as soon as i get a chance and im not so lazy, ill be hooking up the slash cut as we discussed.

thanks a lot man.

Re: crankcase/pcv evac system... ?
 

the hose pointed at the ground is called a downdraft tube, and it was used by all cars until the introduction of PCV. The tube needs to go all the way down to the bottom of the car, maybe even stick out a bit. The idea is similar to the exhaust idea, passing air current creates a slight vacuum.

If you have fuel in your oil with an open hose off your crankcase, ventilation is not the cause of your issues, you have something else very fucked up.