PDA

View Full Version : Catch can?



Dave
01-07-2006, 06:23 PM
There seems to be a good debate on the PCV system lately. Right now the van's PCV system is just a hose running from the PCV valve to behind the K-frame with some foam stuffed in. I know the passing air causes SOME vaccum, but not much.

So I want to try something different this year. Maybe welding a bung onto the intake pipe and running the PCV line from the valve to the bung.

But I don't want to burn oil, it decreases the octane level and causes a more liability towards detonation... which is bad. :nod: So I can put a catch can in between the bung and valve to of course catch the oil.

That begs a few questions:
(1. Where can I get a catch can? Does somebody produce them? Or can I make a home-made one?
(2. How the hell does a catch can even work? I know it traps the fumes but still draws vaccum, this way no oil is ingested into the intake track.

Thanks for any help.
-Bryan

looneytuner
01-07-2006, 08:34 PM
Well the Neon site that had directions for a $20 can disappeared. It was a oil filter for air compressor line. It said it worked better without the foam filter. I think it was purchased an Home depot. Grainger should hae one. I have a GReccy one in polished aluminum that should hold about a pint of oil. (100,000 MILES BEFORE DRAINING. Your i/c will hold a lot of the vapors.

The foam filter on the oil filter one makes a cute air filter for the solenoids.

bill2
01-07-2006, 09:31 PM
The 20$ catch can is an air compressor filter (home depot or grainger) with two fittings on both sides of the filter. Cut the vacuum tube that connects your intake to your pcv and voila, oil collects in the catch can instead of the intake. On my neon it helped but didn't keep 100% of the oil out.

Have you considered an exhaust scavenging setup? Keeps the pressure off of the crankcase and the oil out of the intake! Either way should work better than a road draft tube.

Blue Iroc R/T
01-07-2006, 10:13 PM
Bryan,
Summit Racing has a nice looking Plastic Catch Can with pit ---- on the bottom for less than $20. You could put a Tee in the top with hose barbs to each side. They have them Red or Blue. Would look nice in that new engine bay. Summit # SUM-G1477
http://store.summitracing.com/default.asp?Ntt=catch+can&searchinresults=false&Ntk=KeywordSearch&DDS=1&N=115&target=egnsearch.asp

85_600
01-07-2006, 10:22 PM
There are some really decent ones on Ebay. I'll have to look for the links but I thought at least to let you know first about them. Let me check and get back to you...that is if you want something a little better than the air compressor version. I didn't have any problems with the air comp. one I ran on my Saturn, except for the rubber O ring on the lid. It came off during a check of the fluid level and for the life of me I couldn't get it back in the lid, to stay. For simplicity though, the air comp. onces are great, just the Ebay ones are bigger and better made.

85_600
01-07-2006, 10:26 PM
Here ya go:

Ebay Catch Can (http://cgi.ebay.com/ebaymotors/UNIVERSAL-OIL-CATCH-TANK-CAN-RESERVOIR-ALUMINUM-ANY-CAR_W0QQitemZ8028483288QQcategoryZ33556QQrdZ1QQcmd ZViewItem)

I believe that was going to be my next one, if my Saturn wasn't killed :o

Dave
01-07-2006, 11:10 PM
Hey Ralph I think I'm going to run up to Summit tomorrow and buy one of those... thanks!

turbovanmanČ
01-08-2006, 12:01 AM
Thanks, I just bought that EBAY one, I couldn't pass up that price and I need one, keep blowing oil out of my breather so I will plumb that in to the fresh air side, no oil is in my PCV system.

Dave
01-08-2006, 03:17 PM
http://static.summitracing.com/global/images/prod/large/sum-g1477_w.jpg

ok i just bought this.....but it comes w/ a L fitting, should i place a T fitting on it instead or place the pcv lines on the top and bottom?

looneytuner
01-08-2006, 03:56 PM
I don't know how well that will work. You need and innie and an outtie. And stand it on end. But then the innie would be on the bottom and the air would bubble through the oil in it. The Greddy has innie and outtie separate on top.

(Wrote this so the ladies here would also understand) :)

Moparbishi
01-08-2006, 04:44 PM
i bought the ebay one aboout 4 or 5 months ago. got a bag of steel wool for 1$ and filled it up to catch the fumes.

turbovanmanČ
01-08-2006, 04:53 PM
http://static.summitracing.com/global/images/prod/large/sum-g1477_w.jpg

ok i just bought this.....but it comes w/ a L fitting, should i place a T fitting on it instead or place the pcv lines on the top and bottom?

Hmmmm, yeah, you need an innie and outtie on top. That won't really do anything unless you add another fitting. Put the tap at the bottom, then drill and install another fitting on top and it would be alright, sort off, theres probably no internal baffling to help the oil get seperated from the air so really, it looks useless.

Dave
01-09-2006, 12:38 AM
urgh, back to returns than back to Ebay.

firebaron90
01-09-2006, 03:12 AM
Why not just make a catch can from PVC pipe, two caps, two brass barbs, some steel wool, some RTV, and a drainc@ck at the bottom. Then size the PCV pipe to a spare coil mount for the j yard. How much can that cost??? 15 bucks and a half hour of your life??

Joe

turbovanmanČ
01-09-2006, 04:00 AM
Why not just make a catch can from PVC pipe, two caps, two brass barbs, some steel wool, some RTV, and a drainc@ck at the bottom. Then size the PCV pipe to a spare coil mount for the j yard. How much can that cost??? 15 bucks and a half hour of your life??

Joe


I was going to use the compressor one but hell, can't beat $8.95 for the real deal, :thumb:

firebaron90
01-09-2006, 02:12 PM
Read the fine print simon. the ebay auctions are 8.95 plus 14.99 shipping. i love when the shipping is more than the item.

Joe

turbovanmanČ
01-09-2006, 02:25 PM
Read the fine print simon. the ebay auctions are 8.95 plus 14.99 shipping. i love when the shipping is more than the item.

Joe

I did, its still a steal, considering to buy one in my neck of the woods is $150. I will gladly pay $26 US for a catch can shipped to my PO Box, :thumb:

Mario
01-09-2006, 04:04 PM
A Campbell Hausfeld IronForce Series 1/4" NPT Mini Air Filter works great too. You can get one from Lowes or Home Depot.

Marcus86GLHS
01-09-2006, 04:39 PM
back in 2004 on another website i asked the question, "does the stock PCV outlet hose going to the airbox have to see a vacuum to work right?"

i asked that because, in my experience, a decent vacuum is not achieved on any engine unless you measure after the throttle blade. so, i figured there is not going to be much vacuum upstream of the throttle body (in the airbox). even on a turbo, where the compressor may be drawing in more air volume that a N.A. engine, the vacuum would have to be extremely low inside the airbox, provided the airbox inlet was not obstructed of course.

i rec'd numerous recommendations, most saying "dump the PCV outlet tube overboard (attach a filter at end) because the tube does not need vacuum to operate properly."

that made sense to me, so that was what i did. i pulled the tube out of the airbox, extended it to below the trany, and put a small filter on end. that totally solved the oil-in-intake tract issue, and engine seems to work well, no smoking issues, etc. of course, i've only put 600 miles on the car since 2004.

so now i am asking again: how much vacuum could be in the airbox? not a lot i bet, so why would the PCV outlet tube need to be routed to vacuum? did i screw this one up?

turbovanmanČ
01-09-2006, 05:56 PM
so now i am asking again: how much vacuum could be in the airbox? not a lot i bet, so why would the PCV outlet tube need to be routed to vacuum? did i screw this one up?


Ok, our pcv system has 2 sides, looking at the engine, the valve cover has the rubber T-left side goes to the intake-thats your pcv valve-the engine at idle and cruise or in vacuum draws unwanted vapours/blow by etc back into the engine to be reburned. The other side goes to the air box. This is done for 3 reasons-1)Obviously when the PCV is sucking, it needs a bit of fresh air so routing to the airbox gets your clean air, 2)When in boost, the PCV valve is closed so now, the crankcase vapours need to go somewhere-and back they go into the air filter to be reburned and theoretically, the engine will also burn any oil vapours so theres no mess outside the engine. 3) For emission purposes-this stops any HC's and oil from going into the atmosphere.

Routing the fresh air side outside IE no air box is fine as many do, but also sometimes, you get oil spray issues so you can use a catch can on that side or make another fitting on the intake. It really is a piss poor design and they should have used to sources rather than one-one for the pcv and one for fresh air, like all V8's and most other engine designs.

Marcus86GLHS
01-09-2006, 06:28 PM
right i forgot about the rubber T, my nomenclature wasnt exactly correct, you are right......my original issue way back then was how to stop oil from getting into the intake track, before the throttle plate (my airbox, intercooler and all piping had puddles of oil inside)....pulling the breather hose that goes between the rubber T and the airbox, and instead dumping it overboard, solved all oil ingenstion before the throttle body (and i do see a drop of oil under the car every so often). but you're right the PCV still goes to the intake manifold (ie: vacuum).

so the catch would go at the end of this breather overboard dump right?

Mario
01-09-2006, 07:23 PM
http://boostedmopar.com/forums/showthread.php?t=713

turbovanmanČ
01-09-2006, 07:30 PM
so the catch would go at the end of this breather overboard dump right?

I am doing this yes, routing the open end into a catch can and this should solve my and anyones oiling issues-IE oil being blown out of the tube/breather.

cordes
01-09-2006, 07:48 PM
Here ya go:

Ebay Catch Can (http://cgi.ebay.com/ebaymotors/UNIVERSAL-OIL-CATCH-TANK-CAN-RESERVOIR-ALUMINUM-ANY-CAR_W0QQitemZ8028483288QQcategoryZ33556QQrdZ1QQcmd ZViewItem)

I believe that was going to be my next one, if my Saturn wasn't killed :o


You can't beat that for 26 bucks.

turbovanmanČ
01-09-2006, 07:53 PM
You can't beat that for 26 bucks.


Nope, can't wait to install it, :thumb:

cordes
01-09-2006, 07:54 PM
Nope, can't wait to install it, :thumb:

Post some pics when you are done, I bet that will look pretty sweet.

turbovanmanČ
01-09-2006, 07:54 PM
Post some pics when you are done, I bet that will look pretty sweet.


No problem, will do. :amen:

Dave
01-11-2006, 10:42 AM
Okay so this still leaves some unanswered questions... will the catch can "catch" ALL oil vapors from entering the intake track?? I think the purpose of it is to prevent oil from being ingested but still retaining the vaccum.

And to answer the question as to how much vaccum is in the air box, or even on a bung in the intake pipe? Oh god you have no idea! Stick your hand over the intake pipe to the turbo so that it's about flush, have somebody boost it up... you have no clue how hard that thing sucks, and that's at only around 0-6psi. Imagine running a good system say at around 18psi, you'll be sucking all sorts of oil out. My guess is, a lot of vaccum is in the intake.

But now I wonder, how much vaccum is too much for the PCV system?? Don't track-built cars actually have a system to monitor PCV vaccum? Or don't they have an additional sump or something to pull more vaccum through the PCV? I remember hearing something crazy like that.

cordes
01-11-2006, 12:44 PM
I don't think that the catch can will ever get all of the vapors, but shy of the exhaust method, I don't see a better way. I think a catch can with a baffle in it is they way to go for most of us.

turbovanmanČ
01-11-2006, 01:14 PM
But now I wonder, how much vaccum is too much for the PCV system?? Don't track-built cars actually have a system to monitor PCV vaccum? Or don't they have an additional sump or something to pull more vaccum through the PCV? I remember hearing something crazy like that.

Theres no such thing as too much vacuum in the crankcase. Some race engines have vacuum pumps on the engine so suck out as much internal pressure as they can.
A catch can should be able to get almost if not all of your vapours around, and even what it can't catch, isn't enough to worry about.

turbovanmanČ
01-15-2006, 05:21 AM
Those guys don't mess around, shipped Tuesday, I picked it up today. Not bad, its pretty compact, has a clear level tube on the outside, mounting brackets, clamps, bolts, nuts and some blue clear tubing. The hardware is worth more than the price I paid. The drain is in the bottom, they have it so you unscrew a plug but that would be messy so I got a drain---- and some hose to drain it. The inside isn't baffled but its deep enough that it shouldn't matter.

I mounted it on my strut bar, ran the drain in behind the tranny so I can just use a drain pan at work, took off the metal pipe and filter off the stock T, ran a fitting they supplied and put that into the T, ran the hose to one of the fittings on the can, ran the other fitting with some more hose to my filter again. Drove it hard on the way home, no signs of oil in any tubing, awesome. :nod:

http://i12.photobucket.com/albums/a228/turbovanman/Canoncamerapics008.jpg

http://i12.photobucket.com/albums/a228/turbovanman/Canoncamerapics009.jpg

http://i12.photobucket.com/albums/a228/turbovanman/Canoncamerapics010.jpg

http://i12.photobucket.com/albums/a228/turbovanman/valvecovergrommet.jpg

firebaron90
01-15-2006, 06:00 AM
When all is said and done, I will have a small air compressor catch can between the PCV and the intake, and a full sized one from the PCV elbow, to the catch can, then to the intake.

JOe

firebaron90
01-15-2006, 06:02 AM
Is that plastic?? Can it be opened up so one could put steel wool in there to acclumilate oil???


Not bad.

turbovanmanČ
01-15-2006, 06:12 AM
Is that plastic?? Can it be opened up so one could put steel wool in there to acclumilate oil???


Not bad.


No, its aluminium. I guess it could be cut apart and modified. I left the pcv alone as no oil gets suck in, I am blowing oil out, :(
I will let you guys know how it works in a few weeks.

I was going to do the compressor thing but for the price of can, all the hardware, wasn't worth it.

cordes
01-15-2006, 08:42 PM
Thanks for the pics and the initial report Simon. It looks good.

85lebaront2
01-15-2006, 09:15 PM
I'm thinking about trying the trick MB used on the turbodiesels. Since most diesels have no manifold vacuum, and occasionally some wicked blow-by, they designed a system that would catch liquid oil pushed out of the valve cover, then return it to the crankcase. I agree with Simon on the poor design, but look at the engine they copied, the VW Rabbit, it has the same design. Many european engines are that way. The in-out PCV seems to be more of an American design, and most in-line engines use opposite ends of the valve cover. Hey, Simon, ever worked on a British engine with a Smith's valve, or the ones with nothing but an orifice, talk about primitive.

turbovanmanČ
01-15-2006, 10:10 PM
Hey, Simon, ever worked on a British engine with a Smith's valve, or the ones with nothing but an orifice, talk about primitive.


No, but I work on Jeeps and they have the orifice design, :(