I have been running a blocked off PCV, w/ just a breather filter (no catch can) on my turbo setup for a week now, w/ not a drop of oil out of the filter. Well I looked in my engine bay this afternoon and my freshly painted valve cover and the entire back of my block was covered in oil from blow by through the breather filter. I had some part throttle misfire issues related to bad IAT sensor that I think caused the massive amount of oil spew.

I've decided that I'm going to run both valve cover ports to a sealed catchcan (probably a cheap (~$12) air compressor moisture remover w/ the filter removed) then to a slash cut tube welded into my downpipe. This is said to generate a great vacuum level (2-8 in/hg) within the crankcase depending on load, the more vacuum at higher load, which is what you want as it helps to seal your rings, and remove the corrosive blow by gases and contaminates that can eat away your engine and sludge your oil. The only other way to do this is with expensive purpose built pumps.

This is said to give a 2-5% whp increase when done properly, and will keep your engine lasting longer.

More details on different types of PCV setups here: http://www.honda-tech.com/zerothread?id=1199935

Im running a catch can with both lines to the catch can then to the 3" piping between my air filter and turbo. Havent had any probs and have been using it like this for roughly a year now.

I'm talking about more than no problems, I'm talking a performance gain, and better care to your motor. If you did a slashcut tube going into your intake it will generate some vacuum under load, but not as much as the hot, expanding, exhaust gas can. You also have to clean your compressor housing and intercooler periodically using the slashcut intake evacuation method. It's the next best PCV setup to a pump or exhaust evacuation.

http://tinyurl.com/bqjpr

Summit has two decently priced kits available.

Originally posted by Ducking_Fumbass
http://tinyurl.com/bqjpr Summit has two decently priced kits available.

So what are we saying here? These kits arent worth it. Id like to learn more about this, but Im not gonna waste my time if you "already been there" guys think its a waste of time.

I'm running an exhaust crankcase evacuation system.

Originally posted by WickedESi
I've decided that I'm going to run both valve cover ports to a sealed catchcan (probably a cheap (~$12) air compressor moisture remover w/ the filter removed) then to a slash cut tube welded into my downpipe.

Why are going to put a catchcan in there? Just let it go out the exhaust... unless you're running a catalytic converter, in which case you shouldn't be using an exhaust crankcase evac. system.

Originally posted by WickedESi
This is said to generate a great vacuum level (2-8 in/hg) within the crankcase depending on load...

Maybe 4 or 5 in/hg max, but it's not going to pull 8 inches through the turbo exhaust of a 420A. You don't want that much anyways, because it's just as bad on your seals and gaskets as a few pounds of pressure. 4 in/hg in the crankcase works perfect.

Originally posted by WickedESi
the more vacuum at higher load, which is what you want as it helps to seal your rings, and remove the corrosive blow by gases and contaminates that can eat away your engine and sludge your oil. The only other way to do this is with expensive purpose built pumps. This is said to give a 2-5% whp increase when done properly, and will keep your engine lasting longer.

Yep. But it's hard to do properly. The two ports on the valve cover are not even big enough to evacuate the pressure, so you shouldn't waste your time unless you're willing to modify your value cover in a big way.

We discussed it in this thread:
http://forums.2gnt.com/dcboard.php?az=show_topic&forum=5&topic_id=89192&mesg_id=89192&listing_type=search

Originally posted by dougie2
Why are going to put a catchcan in there? Just let it go out the exhaust... unless you're running a catalytic converter, in which case you shouldn't be using an exhaust crankcase evac. system.

The reason for the catchcan, besides probably being needed to be race legal, is just so you can monitor how much, if any, oil is being sucked out, or spewing out, and not confusing it with blue smoke from a leaking seal in your engine. Only very complicated baffles would completly prevent this, as there is a baffle to the oil cap and mine has been leaking oil all over because the cap is worn out. The air compressor dryer would be a good way to monitor any oil loss, and not induce a noticeable pressure drop. People with cats can still run an exhaust evac system by placing a slashcut, or welding a tube at a 45* or less angle after the cat, where pressure is low and velocity is high very effectively.

Originally posted by dougie2
Maybe 4 or 5 in/hg max, but it's not going to pull 8 inches through the turbo exhaust of a 420A. You don't want that much anyways, because it's just as bad on your seals and gaskets as a few pounds of pressure. 4 in/hg in the crankcase works perfect. ... The two ports on the valve cover are not even big enough to evacuate the pressure, so you shouldn't waste your time unless you're willing to modify your value cover in a big way.

I'll put a guage on it to see what I can pull on my setup. If you're getting more blowby then a 1/2" and 3/8" (7/8" total) hole can evacuate then there is a serious problem. But let's say you did, you will still have a that much less positive pressure in your crankcase, sealing everything that much better, which is why the 2-5% whp increase still stands. Sounds like a win, win situation to me...

To those wanting to do this, the thing to consider is the exhaust gas velocity. If you have a huge exhaust, you will probably want to make a huge slashcut to compensate volume for the lower vacuum you'll pull, which is why you might of not had the best results dougie. If you have a 3" downpipe that transitions to say 2 1/2" you'd want to put the slashcut in the 2 1/2" section for Bernoulli's principle to work best.

I've read the other thread before, but I wanted to start one for this topic alone so it wouldn't look like I was hijacking the DIY:Catchcan thread.

Originally posted by WickedESi
The reason for the catchcan, besides probably being needed to be race legal, is just so you can monitor how much, if any, oil is being sucked out, or spewing out, and not confusing it with blue smoke from a leaking seal in your engine. Only very complicated baffles would completly prevent this

You don't need to install a catchcan with these system to be NHRA legal. Also, there should be no oil sucked or spewing out of your engine. This would be bad. The evac systems on the market all have provisions to keep the oil inside the engine. All you'd be doing with a catchcan is adding volume to the system. In a properly designed system, there will never be enough pressure in the crankcase to force oil out of the engine.

Originally posted by WickedESi
People with cats can still run an exhaust evac system by placing a slashcut, or welding a tube at a 45* or less angle after the cat, where pressure is low and velocity is high very effectively.

Yeah, you could... but who wants to run a big ass hose from there valve cover to the back half of the exhaust? You're also increasing system volume if you do that.

Originally posted by WickedESi
I'll put a guage on it to see what I can pull on my setup. If you're getting more blowby then a 1/2" and 3/8" (7/8" total) hole can evacuate then there is a serious problem.

How do you know? I went through 5 or 6 different systems before I found one that actually worked at all. Trust me when I say you can't just connect the two small ports on the valve to the exhaust valve and evacuate all the crankcase pressure. You'll never reach vacuum in the crankcase if you do. I use a single 2" port on the valve cover.

Originally posted by WickedESi
But let's say you did, you will still have a that much less positive pressure in your crankcase, sealing everything that much better, which is why the 2-5% whp increase still stands. Sounds like a win, win situation to me...

True... but like I said, you want a little bit of vacuum in the crankcase. Even if you bleed off a little bit of the pressure, you're still going to blow cam seals, oil pan gaskets, etc.

Originally posted by WickedESi
To those wanting to do this, the thing to consider is the exhaust gas velocity. If you have a huge exhaust, you will probably want to make a huge slashcut to compensate volume for the lower vacuum you'll pull, which is why you might of not had the best results dougie. If you have a 3" downpipe that transitions to say 2 1/2" you'd want to put the slashcut in the 2 1/2" section for Bernoulli's principle to work best.

No no no... you don't have to do all that. Really, do what you want, but I'm tryin to tell you what actually works. You need to run a standard crankcase evac system, without a catchcan, with a short hose and a large port on the valve cover. Anything else and you are wasting your time. Do what you want, though.

Hold on, I didn't know you had one on your 420a, I was thinking just your project 4g63. Where did you put your 2" hole on your valve cover? Can you post any pics? I was just trying to say for people who don't want to put in the time to make a system that actually creates vacuum in the crankcase, they still can significantly reduce the positive pressure by running the existing ports on their valve cover to their exhaust.

I, however, wanna do whatever it takes (unless it costs a lot of money) to get that small amount of vacuum in the crank, so I'm very intrested in your setup. Are you connecting to your downpipe from the front of the engine, or the back?

Agreed with what your saying and have seen this discussed before on other boards, seems like a good idea in theory but alot of work.

But what im not understanding is how this creates a horsepower increase. From what i understood this was just a preventive measure to keep your crankcase evacuated from corosive fumes and blowby.

Im running a straight exhaust vent system. i dont run a catch can and no pcv either.

The hp increase comes from your rings sealing better, forcing more pressure to push the piston down, instead of sneak around it. Blow-by also can froth the oil, which would increase friction on the bearings in the motor.

I'm trying to get a hold of some large silicone hose so I can finish my setup.

Originally posted by WickedESi
The hp increase comes from your rings sealing better, forcing more pressure to push the piston down, instead of sneak around it. Blow-by also can froth the oil, which would increase friction on the bearings in the motor. I'm trying to get a hold of some large silicone hose so I can finish my setup.

Well, you better share it, lol.

I wasn't saying that it is a waste of time. Rather, I was stating that Summit has a couple of kits that might give you a good head-start on putting this system together, but that I don't have enough firsthand knowledge to be more helpful than to simply offer a link. :P