Venting crankcase to the oil pan?

**rs4pro3** · 10-28-2007, 06:21 PM

Ok I just put an eaton blower on my m20 engine a week ago. As a temp fix to keep from pressurizing the crank case, I just have the line from the valve cover venting to atmosphere. Now I want to change this as the car smokes some from the vent after shutting it down. I already have a fitting on my oil pan that I could just run a hose straight from the valve cover to the oil pan. Are there going to be any downsides from doing this? Or I have an s14 oil separator that does the same thing but then vents the fumes back into the intake, and drains the oil residue to the pan.

**patrick S** · 10-28-2007, 06:29 PM

I could just run a hose straight from the valve cover to the oil pan

no idea what you are trying to say but
m20 has oil pan and head are already connected with pipe just under intake manifold.
just use oil separator and vent to atmosphere?

**rs4pro3** · 10-28-2007, 06:34 PM

I'm trying to figure out what to do with the hose coming off the top of the valve cover. I don't want to just vent it to the atmosphere anymore as it smokes pretty bad.

**promp3** · 10-28-2007, 06:36 PM

no, you can't. Think about it logicly, you need to vent it to the atmosphere, or into the intake of the super charger.

any positive manifold pressure would go into the crank case if you ran the pcv to the intake manifold or a charged air pipe, running a tube to the oil pan would be the same as if you had no pcv...wich is bad.

if you are gettting lots of smoke from the vent you have excessive ring blow by, sticking the tube in somthing isnt going to make that go away. It will still be smoking just going back into the engine and eventualy building up sludge on everything on the intake side

alittle bit of smoke wafting out after you shut the engine off is pretty normal.

btw I have a rs4 pro2 and a nitro...they don't get played with much anymore

**someguy2800** · 10-28-2007, 08:08 PM

Just put a fitting in the intake piping before the supercharger. After the throttel body is best but I don't know if thats possible on your setup. Any pics?

**kendogg** · 10-28-2007, 08:40 PM

Get a catch-can from TRM and run a hose from your valve cover to somewhere in-front of your supercharger (not sure how your setup is made, but it needs to be before pressurized air, ie, before both blower and TB).

**rs4pro3** · 10-28-2007, 08:54 PM

Here are pics of the setup. I've got the throttle body off right now to properly plug those left over fittings from the ICV and Valve cover vent

I'll probably just try and find somewhere to stick the s14 oil separator I have it's just so dang big, a catch can almost sounds like a better option.

**kendogg** · 10-28-2007, 09:08 PM

OK, so your Tb is still in the stock location, after the blower. Good to know.

Now - valve cover vent -- catch can -- somewhere between your air filter, and your supercharger inlet.

**rs4pro3** · 10-28-2007, 09:10 PM

Ok cool, now to find a nice smallish catch can

**kendogg** · 10-28-2007, 09:12 PM

Originally Posted by rs4pro3

Ok cool, now to find a nice smallish catch can

www.racersmarket.net.

If he doesn't have any on the site yet, just shoot techno a PM, I know he has some small-ish ones on the shelf.

**Matt** · 10-28-2007, 10:39 PM

**rs4pro3** · 10-28-2007, 11:13 PM

How much are they Matt?

**promp3** · 10-29-2007, 02:23 AM

http://www.jegs.com/webapp/wcs/store...10002_69732_-1

this is what I have, it is very small the entire thing is about the size of a 12oz soda can, and it dosent stand out.

**kendogg** · 10-29-2007, 02:29 AM

Originally Posted by promp3

http://www.jegs.com/webapp/wcs/store...10002_69732_-1

this is what I have, it is very small the entire thing is about the size of a 12oz soda can, and it dosent stand out.

Ouch thats expensive.

Matt, there are still a few more of those smaller ones on the shelf too, right?

**Matt** · 10-29-2007, 02:31 AM

Dunno, I'll look tomorrow, find out prices, and report back.

**Matt** · 10-29-2007, 03:43 PM

Okay...

Rectangle ones like I posted above are $35 + actual shipping and we also have small round ones:

Also $35 + actual shipping.

Both styles include hose, hose clamps, and mounting brackets. The round ones are all silver, and we have the rectangle ones in red, silver, and blue.

They'll be up for sale on www.racersmarket.net/catalog this evening.

Matt

**a32guy** · 10-29-2007, 04:35 PM

Interesting thread I came across:

http://www.honda-tech.com/zerothread?id=1199935

**promp3** · 10-29-2007, 07:37 PM

$35 is a very good price, but those arn't vented catch cans. I guess you could just leave one nipple open and then it would be vented.

that jaz thing is expencive(I should know I payed for it

) its also just molded plastic, but its the only one that could work where I wanted to place it. its got two fittings and one pitcock so I ended up venting the dipstick and the valve cover. the sludge goes out the bottom and the vapor goes out the filter.

you could also run the valve cover hose to one fitting on the catch can then run another hose to the intake before the throttle body, then you would be recirculating the vapor, and mixing in fresh air through the mini filter, maybe allowing some of the oil mist and bad stuff to settle and be caught in the catch can, before it gunks up the intake.

Originally Posted by a32guy

Interesting thread I came across:

http://www.honda-tech.com/zerothread?id=1199935

about the honda tech thread, increased hp with a vacuume on the crank case due to reduced windage loss is total bullshit!

first off, at about half throttle and up your manifold pressure is pretty much 0 in of vaccume anyway END OF STORY!

I have never heard of anybody running vaccum pumps on their pcv, do you really think if it made hp this stupid honda thread is the only place you would hear about it?
as far as I know pressure has nothing to do with windage.
I have heard people that think vaccum helps the pistons go down easier or somthing. the combustion chamber has tons of pressure behind it, if there was pressure fighting the pistons movement it would blow out every seal well before the engine lost hp don't ya think.

**Matt** · 10-29-2007, 07:40 PM

The idea is that you don't vent it... you run a line from the valve cover to one nipple, then from the other nipple to the intake pipe. The catch can catches oil but lets gasses from the crankcase pass into the intake pipe.

The round ones are 2" diameter by 5" tall... they'll fit almost anywhere.

**promp3** · 10-29-2007, 08:11 PM

Originally Posted by Matt

The idea is that you don't vent it... you run a line from the valve cover to one nipple, then from the other nipple to the intake pipe. The catch can catches oil but lets gasses from the crankcase pass into the intake pipe.

The round ones are 2" diameter by 5" tall... they'll fit almost anywhere.

yea ok, are they baffled on the inside? either way that will work fine, sorry if I diddnt make that clear. one thing I got from that honda tech thread is the idea of putting steel wool on the inside to act as a filter to catch any oil mist and such, the only bad part is that steel wool could make it into the intake

they look pretty good and for that price I may even want to pick one up just to have around for a future car, they are alot nicer to use than a 16oz plastic soda bottle.

**paul e** · 10-29-2007, 09:03 PM

I use one of these.. ITs the smallest ive seen, and its easy to fit. Nicely made with 1/2" NPT fittings. And you can get them for under 20 bucks.

**kendogg** · 10-29-2007, 10:30 PM

Originally Posted by paul e

I use one of these.. ITs the smallest ive seen, and its easy to fit. Nicely made with 1/2" NPT fittings. And you can get them for under 20 bucks.

That looks like a filter for an air compressor, lol/.

**Matt** · 10-29-2007, 10:37 PM

http://www.racersmarket.net/catalog/...ba47c9bcadacd5

Not sure if it's baffled on the inside. I would think so, since it is a purpose-built catch can. I'll take one apart tomorrow and see.