MalcolmV8

Over the last few months I've been playing around with different oil catch can configurations and one common thing I've noticed is when you drive the car hard they sure collect a lot of oil. So much so that I'm sick of sucking out the oil with a syringe all the time. I could try and install a nice drain valve of sorts and make it easier but that's just a band aid to the problem.
What I'd really like to do is setup a catch can that drains the oil back to the oil pan after you get out of boost. Anyone done this?

Can I use the same oil return bung in the oil pan the turbo is using and just plumb a T in the line?

Also how do you guys plumb the return line? is there some sort of pressure valve that stops blow by from coming up the line when in boost? and then opens up in normal driving and drains back down?

Thanks for any info.

hon2984

the pics dont work anymore, but this is some good reading.

https://honda-tech.com/forums/showth...se+ventilation

Ash J. Williams

this is the only way to use the catchcan on a street car.


Intake slashcut evacuation
-----------------------------------------------------------------------------------------



Using a slashcut tube to create vacuum is an old trick which works on the Bernoulli effect as air rushes past the tube at high velocities. Make sure you place the slash-cut opening in the opposite direction of the airflow.

One method for evacuating the crankcase is to allow the Intake(pre-turbo) to draw out these gasses. In my tests their was a linear load dependent vacuum drawn using this method. None to insignificant amount of vacuum drawn at idle and low load conditions, moderate load created 0.25 psi(0.5") of vacuum, and high load/WOT created a maximum vacuum of 0.5 psi (1") vacuum. One does not need to use a check valve with this approach as their is never any reason for pressure to force its way into the crankcase.

Their is a positive and negative aspect to this approach. The great thing about this method is that it is the only method which allows one to completely eliminate any blow-by gasses from contaminating the environment. The downside is that it contaminates the Intake charge with oil/fuel/contaminants.

Judging from the amount of contaminants I collected in my open breather catchcan every 2-3 weeks it would be absolutely insane to use this method without a sealed(no open breather element) and baffled catchcan in-line between the crankcase /valve cover and the intake. Keep in mind that most of the contaminants will be sucked into the intake as opposed to only some contaminants trapped in an open breather catchcan while the rest pollutes the environment.

Some good news is that the Intercooler piping and intercooler will act as a very large catchcan and trap most of these contaminants before they reach the engine. The bad news is that I suggest you periodically clean the inside of your intercooler and intercooler pipe.

Bottom Line


Cost: 20-150 dollars(dependent use of catchcan and welding)
Performance: Good(as long as the compressor housing/Intercooler are cleaned
periodically and a catchcan is used)
Reliability: Good.
Environment: Excellent(provided that you use no other open breather elements)

MalcolmV8

I've read that thread. It doesn't say anything about how to plumb a return oil catch can. Well it's a 26 page thread so I didn't read every single post.

That's not for me. I don't want any oil getting sucked through my turbo or intake, intercooler etc. I already have a good working catch can setup which also has a functional PCV system (out of boost) and has no smelly oil smell which is common on many setups. The only thing I need to add to make it perfect is an oil return so it's 100% maintenance free.

Ash J. Williams

if the catchcan is set up properly and is large enough, there is little sludge going into the compressor.

MalcolmV8

Non the less there is. It's besides the point though, I'd still have to empty that catch can and even worse I forget or run to long with it and a ton of excess oil's going into the turbo and everything after it.

4genaccordfreak

This has been done for years.

There are special AN fittings you can buy from either Go-Autoworks or B&R fittings that are the correct thread to tap into the back of your engine block just above the PCV plug, along with a block off plug for PCV black box removal.

Or there is a male -> plug adaptor to remove the black PCV box and hook a line up to it as a drain.

I am currently running the medium setup from Go-Autoworks. all AN line/fittings. 2 from the valvecover into the side of the can and 1 line from the bottom the goes directly into the back of the block above the PCV plug that is blocked off with the provided o-ringed plug. Been working great for me. Doubles as a 3-way vent under boost and the bottom line then drains under low rpm/idle. The oil residue was creeping up and soaking the filter at the top so I bought some stainless steel scrubbies (for washing dishes) at Walmart. stuffed 1 near the bottom and 1 near the top. Works great, still bleeds off pressure/vapour but doesn't allow oil to travel up to the filter.

This is for a B-series engine, but the kits available are for B, D, etc etc.

MalcolmV8

So the part I'm trying to understand is the hose that drains back. It's just a straight hose with no one way valve? I was thinking there was a valve to stop blow by pressure blowing up the hose and into the bottom of the catch can while running it hard in boost. Sounds like that's not required. Thanks for the info it gives me some good ideas.

I actually reverted back to having my black box and PCV valve so I have a functional PCV system while in vacuum / normal driving. This pulls hydro carbons out of the crank case in normal driving which helps keep the oil clean for longer. Without it my oil would turn pitch black almost immediately after an oil change and I've read that without a functional PCV system you're always looking at the possibility of engine sludge from the hydro carbons and other nasty contaminants of blow by never been vacuumed out and contaminating the oil.
I have a brass one way valve inline with the PCV valve so when I go into boost it won't over power the PCV valve.

SiRCiviC94

again isnt the stock black box good for 300HPish I know its personal preference.....I do plan on running two lines out of the valve cover to a breather can but thats about it? and retain the stock black box

MalcolmV8

HP is irrelevant with regards to the black box in my setup. Under boost I have a check valve that shuts it off. In plays no part in venting anything while in boost. It's purpose is purely to house the PCV valve and provide a functional PCV system while driving normal out of boost. Once in boost I have additional lines running out of the valve cover that provide ventilation to a catch can.

4genaccordfreak

I think you are confusing yourself why this is setup the way it is. If anything you WANT to vent the blow-by out from the block/head as much as possible. The reason why it is all vented to atmosphere is due to the fact that the increased pressurization of your block picks up larger droplets of oil/fuel as opposed to a stock/NA setup. You want to steer away from feeding the oil residue and possibly unburnt fuel back into the intake system. Engines built for forced induction require looser clearances because of this increase in cylinder pressure. To compensate for that increase in pressure bleeding past your piston rings you need a better ventilation system with no restrictions (ie: one-way valves, block-off plates or lines and PCV equipment not designed to bleed off the crankcase pressure efficiently). Also, you definitely do not want to add a "vacuum" source on your F/I setup, since when in boost it will pressurize your vent system adding to the crankcase pressure and basically blows oil all over your engine bay and can damage things internally in extreme cases.
In terms of hydrocarbons contaminating your oil... You are running a turbo setup on an engine that was originally not meant for it and I assume the punishment/spirited driving the engine is now seeing is beyond NORMAL by any means. Your oil change intervals should be shortened dramatically anyways and you should be changing the oil long before I would assume it could possibly be contaminated unless your tuning is way off and you have an over-fueling issue. Other than that I wouldn't worry too much about oil contamination or sludge build-up if the setup is vented properly.

Here's a view from my build this past spring.



You can see the -10 line from the back of the block feeding up to the catch can. This doubles as a vent under positive pressure and a drain under vacuum.

Here's a view of the completed top setup.



*Keep in mind this is originally all Go-Autoworks components, although the length of -10 hose they provide in the kit is designed for the valvecover vents on the back side of the cover (not the front like I have done) and the catch can mounted somewhere around the right side strut tower. I purchased more -10 line and relocated the setup they way I wanted*

So basically this setup is all "STRICTLY" ventilation with no assistance from any external source and no back-feed into the intake for "emissions". It is not needed. The setup is building enough pressure to ventilate on it's own. Granted this setup is not emissions legal at all.

Natural Aspirations

If running a return it needs to be plumbec BELOW the oil level in the pan to prevent it from blowing up the return tube. I made a mess of my bay this season.....

4genaccordfreak

^^ That's weird. Mine is fitted to the right/rear freeze plug hole, 3 inches or so above the factory PCV box hole (which is now plugged). I was getting some slight spatter from oil residue soaking the filter (over time) basically because there are no chambers or baffling inside the can. Stuffed 2 stainless dish-wash scrubbies into the can. Never had an issue after that. Should be "mostly" vapour if fitted that high up on the block.

You've been around a long time man, i'm sure you didn't pressurize the vent system. How was yours hooked up to the block to cause that much oil to be carried up to make a big mess?

MalcolmV8

That's possible although I think I have a handle on it and may just not have explained it well above. I'm certainly not beyond learning new things though.

Correct and I completely agree.

Yes I agree here too and I think this is where you are confusing my setup. My valve cover has an additional barb welded in with hose running off to a catch can so blow by can be vented. I am in no way relying on the PCV valve setup to vent all that blow by. In fact when under boost I have an aftermarket one way valve that shuts off that PCV line completely and does not allow any boost to go down to the block. I also have no oily mess been forced into the intake.
The only time my PCV system is functional and sucking air into the intake is at idle and low load conditions. In other words while operating in "stock" mode.

Well I suppose everyone has their theories and so forth on oil changes. I'm certainly not expecting 15,000 mile oil changes or anything like that. For me personally I change every 3k miles using mobil 1. I came up with that interval by sending samples to blackstone labs and finding the oil still had plenty of life at that point (samples from various hot rods over the years, not the civic specifically).

Nice pics, clean looking setup you have.

I was trying to find a pic showing you the brass one way valve I'm talking about. You can see it in this pic just above the fuel rail. See this allows vacuum from the manifold to draw air through the PCV and out the block while in normal low load driving (like stock). Then as soon as vacuum goes away the valve shuts and will block up to 1000 PSI of pressure. Essentially just shutting down that hose and making it irrelevant under boost.

In the same pic below you can see the additional hose coming off the valve cover. It's kinda stealthy and hidden. Look just to the right of the distributor under the spark plug wires. Just plain black looking hose, no AN fittings or anything that look out of place. Just part of the somewhat sleeper look my car has.

Natural Aspirations

I've tried a few different approaches this year with little luck, 4th pull down the 1/4 mile track the tank is full (1QT no return) and starts to spit oil everywhere.
My last appempt was 2, 5/8" hoses run from the top of the black box to an Endyn/Morroso catch can, valve cover nipple open to atmosphere. I went a little loose on my P2W with my pistons and that may be the majority of my issues. I had none of these issues when I was supercharged making half as much power.

4genaccordfreak

^^ Okay. Now I see how you have done it.

So basically from what I am seeing is, you are relying on the single vent from the valvecover to vent your entire system "under boost". Aswell you are noticing alot of oil in your catch-can. This is because all the pressure bled off into the block now needs to travel back up ALL of the oil drain galley's from the head/block. In-turn it is picking up ALOT of oil droplets and vapour on it's way to that single vent on the valvecover.

I understand your idea to try and create a functioning system under normal driving conditions. Although now there is a compromise, which is more pressure up to the head which equals more oil in your catch-can.

Instead of blocking off the line to the block "under boost" (which is where 100% of the additional excess pressure comes from), vent it to the catch-can aswell and isolate the system to be a vent only.

In my opinion the way you have it hooked up will work fine under normal driving conditions but poorly when the venting is most important, when pressurizing the system.

It's all a compromise. If it is meant to be emissions friendly, it will not perform efficiently (for our means with forced induction). If it is meant to perform efficiently, it will not be emissions friendly.

The PCV system is fed back into the intake system from factory due to emissions and emissions only. If no emissions laws existed, catalytic converters would not exist, EVAP systems would not exist and recirculating PCV systems would not exist.

4genaccordfreak

Oh I see, I'm only running .004" P2W (fairly standard for my moderate 400-450whp power level, 16-18PSI), Maybe your high boost pressure/loose P2W and location/too small of vent system all bundled together is basically the issue? Weird that you've tried different setups and still have had no luck. Doesn't really make any sense unless it's all location related.

I've always pondered if the location of the black box on the block was too low and under hard acceleration oil would slosh back and up close-to/into the hole and the crankcase pressure is picking it up through the box and up the lines. Although after some logical thought it seems extreme, especially if the oil-pan is baffled, But nothing can be proven, we can't see whats going on inside while we are going like a bat out of hell down the 1/4.

MalcolmV8

Actually I have two vents on the valve cover not just one. Hard to tell in the pic. I think we are on the same page though.

Even though I have two vents on the valve cover I don't think enough pressure can get from the block up to the valve cover to exit (just a theory). I just ran down to the garage and pulled the valve cover to re-fresh my memory and there's only two ports that are not very big for air to pass from the block to the top of the head. I'm thinking I may have to just give up my PCV system and vent the block directly like you have and make that also double as the catch can's return. My hesitation has been that the PCV system is not just for emissions but plays an important part in preventing sludge build up.

Stealthmode Performance

2 valve cover -10's to catchcan, -10 drain to the back of the oil pan. No valves, slashcut science projects, or anything else.

MalcolmV8

Your setup looks very nice and clean. Any reason you ran the return down to the oil pan instead of the hole in the back of the block where the black box was originally?

Also do you get any oily fume smell in the car? I had to run some hose from the top of my catch can to the under side of the car and put the filter down there to get rid of the smell.

MalcolmV8

Man check this out. A neat valve I can put in place of the oil drain plug and run the return from my catch can directly to it

http://www.quickoildrainvalve.com/se...ts.asp?cat=152

Save me having to pull the oil pan for the billionth time to drill and weld another bung in it and put it all back together.

Stealthmode Performance

My original black box has been blocked for a long time. The barb fitting in the back of the oil pan gives any oil a direct route back to where it needs to go, and the hose from the pan to the bottom of the catch can is long enough that I don't need to worry about anything "blowing" up the hose. It's been good for me.

MalcolmV8

BTW - how is your car right hand drive? At first I thought maybe it was just an inverted image but then I looked closely and no it's really right hand drive.