DuMa

Not sure if our engines need it nor if there is any power to be gained, but will a catch can be vital? actually im sure no power will be added, its more of a cleanup mod so air will be more purer going into the engine.

not sure how much oil vapor our valve head sends to the intake but a catch can should prevent gunk buildup in intake manifold and injectors.

something like this got me curious if it could be DIY for cheap

PCV Catch Can Install

Any thoughts?

____

lo_bux_racer

For an NA engine, no. For a boosted engine, I would highly recommend a catch can, but not like the POS they show in the link you have. The can should be equipped to cool the vapors, usually with some kind of steel or aluminum mesh inside the can. The idea is to cool the vapor as quickly as is reasonable so it condenses. This helps keep your intake as clean as possible if you are still running PCV. Some guys do away with it altogether, but IMHO, that's not a good plan for a street engine.

Some very high performance engines use high volume air pumps to scavenge the crankcase for a few reasons that would take more time to write than I have right now.

HKSpeed

crossflow-engine VW owners use a catch can because the PCV would constantly malfunction and dump oil into the intake tube. sr20det owners use catch cans for the same purpose (but no external PCV). in both cases the catch can is not power producing mod, rather a remedy for an oil leak. i had the misfortune of dealing with it on my sr-240sx (oil in the turbo) and crossflow GTI (oil in the maf sensor).

DynomyteSW

the catch can in your link looks like a water trap for an air compressor... i would agree w/ lo_bux_ look into a better catch can if you are still planning this at all

BrEaK_AwaY

I was thinking about getting greddys can, so lance your saying while im still NA i shouldnt get it? but when i s/c, i should get it?

it wouldnt hert to get it while im NA though would it? i would assume catching that extra bit of oil would help reguardless

ScionDad

The oil catch can serves a purpose, even for NA cars. It traps the liquid and passes the hot gas. Autocross cars and off roaders it helps big time because of the oil slamming around and getting passed out thru the PCV. Even without it, vapor has liquid oil in it. This oil gets sent down the intake and into the carb. The catch can reduces this. I had one on the NA tc (it was a Greddy) and when I removed it to fit the turbo plumbing, it had about t a teaspoon of oil in it...thats from about 5 months and not driven hard at all.

Cheap mod that looks great and actually does serve a purpose.

BrEaK_AwaY

sciondad, would you like to direct me where you purchased yours? and pictures / process of your install so i can figure out how to mount it. I remember me and you discussing this before... but my short term memory is horrible.

Thanks!

ScionDad

Well, I got it off ebay and all the instructions were in Japanese, so I just figured a way to install myself. When I removed the stock intake, there was a mount spot right there for a thread in bolt to go. I used a piece of universal strapping (holes punched in it), and at a right angle, just attached it. Just make sure your hood will close without hitting.

From the PCV output on the top of the engine, route to the can, out of the can and to the CAI. Just make sure you get the 9mm hose size can. It's mounted right behind the red battery cover.

BrEaK_AwaY

sounds like something im gonna do within the next two weeks. i wounder if that spot for a bolt is for mounting the trd supercharger... if so im gonna be fooked there cause i plan on getting it. i know there are a few spots on the motor that have placed for bolts, and im assuming its to mount the sc.

ScionDad

You might want to look at a pic of one already installed and see if that spot is taken up by the SC plumbing to get to the throttle plate. The turbo plumbing did that.

DynomyteSW

The area where the catch can is in the pic above wouldnt work for s/c the blower outlet is there

lo_bux_racer

You are better off if you can firewall mount it, or put it some place where it will stay cooler than mounted to the cylinder head. You want the can to condense the vapors if it can. When it's hot, it can't do that as well.

ScionDad

^^^ Yup. The mount I attached to is the old support for the factory intake in the bay.

Greddy makes another version which side mounts and would work much better on the fire wall.

BrEaK_AwaY

could anyone direct me there? cause i am deff intrested in this, and i forgot that the SC mounts directly there.... sigh...

ScionDad

there are some available on ebay. just be careful though as some are not work safe.


*Edited by Sexyscionlover*

Scott17

Did anyone ever consider that the minute amount of oil vapor directed into the intake migh actually be a GOOD thing? REAL race cars don't use oil catch cans unless rules specify them to keep the track clean. Drag cars use venturi plumbing into the header to scavenge crankcase pressure. Cars that pull a lot of Gs on a road course can benifit from one to keep the track dry. Off road racers use them with a return to prevent excess oil loss. Your stock street car will not benifit one IOTA from an oil catch can. This is the purest form of RICE (racing inspired car enhancement). It might look pretty but don't kid yourself for one minute that it will "improve" anything or give any performance gain. It would look nice sittin' next to that Turbonator though!

ScionDad

No, I didn't consider such a thing because that's just stupid. Who said anything at any time about performance increase. What a dork sometimes Scott. A catch can is primarily better for your car because you aren't injecting oil into your oxygen supply! Next up, oil vapor is hot and as it travels through your system it will stick to cool surfaces and build up! Anyone up for oil buildup throughout your entire intake path? It's gatta be a good thing....right? Think long term Scott.

Also, all the "race" cars you talked about don't run 200,000 miles in between total rebuilding, or simple tear down..I'm thinking, after 200K, my intake path will be cleaner and perform better than one without. That is an IOTA and that would help prevent a performance reduction in the long haul. But, you'll probably tell me how sludge can be your friend.

Oh...I guess you meant it would look nice next to my turbocharger... Sure would Right back there on the firewall

lo_bux_racer

ScionDad, you missed the most important issue: oil in the cylinder promotes detonation. Oil has a very low octane rating, and it can (and does) promote detonation in a big way.
FWIW, a LOT of that intake varnish is caused by reversion at low throttle openings, not oil from the PCV system, and the reversion discussion is a whole thread by itself, but suffice it to say, I've seen intake varnish in street bikes running smoothbores/flatslides with open stacks.

Also Scott, notice what I said: I would not do this to an NA engine, it has limited benefit. I would unquestionably do it on a boosted engine because the rings are going to have more blowby, even in engines designed with boost in mind. Supras are notorious for having oil migration problems in the turbo intakes from the crankcase connection that is supposed to provide fresh air for PCV. It just ends up being a conduit for oil into the preturbo intake leading to poor performance and that nasty detonation thing again. I poured 3 ounces of oil out of my intercooler once, and another 3 ounces out of the tube at the bottom of the engine that feeds the throttlebody. I guess the intercooler was doing a great job of condensing the oil vapors eh?

You're short-changing the drag racers too. Some of them are actually running scavenge pumps on the crankcase to reduce the pressure below atmospheric. It keeps the inside clean and reduces pumping losses (you know the stuff, from all that up and down motion of the pistons). It actually produces more power gain that it takes to run the pumps. Pretty rare, but pretty cool too.

ScionDad

That is a very good point about detonation and actually was one of the first things I was told by my brother when I was opting for turbo. For a NA engine, it's more about the bling by far. But, IMO, if you're gonna do it, it sure won't hurt anything and at best it will help keep things clean in the long run.

That's funny about the intercooler oil issue. I've seen that happen and watching the expression on their face and my jaw drop as the oil is poured out of the intercooler. Not funny at the time, but it is now. Sure causes some panic at the time.

BrEaK_AwaY

kool. so ill deff be gettig this soo. i just need a greddy side mount can with a 9mm hose fitting. il do it now will im NA, so i wont have to worry about it once i get s/c'ed