Vented or Non-Vented Oil Catch Can?
 

I currently have a small 1 pint Jazz Catch Can with a K&N breather filter on top. Lately, its been filling up pretty quickly with watery fluids and am moving up to a larger 1 Quart size. The larger cans don't have breathers on them and I'm wondering if its even necessary.

Can someone please enlighten me on why a breather would be needed on an oil catch can?

Would one w/o a breather NEED to be routed back to the UIM?

Thanks.

This is for an FD running twins.

You'll want to release some of the crankcase pressure somehow. So you can either keep the line going to the UIM, or you can vent the catch tank (whether that's with a filter or plumbing it back to the primary intake elbow). I haven't installed mine, but I'll be running the outlet back to the primary intake elbow.

+1

I've got mine plumbed to the primary turbo so that it's constantly under suction. I'm pretty sure if you ru it just to the UIM, the boost with push back the wrong way.

My can is big enough, and the two inlets are positioned such that that no oil actually get's sucked into the turbo.

Hmmm...

I just have a tube coming from the filler neck to the catch can. It's basically the old Crispy style setup that has been on the car since the previous owner. The UIM nipple is capped off right now.



Another question:

Which larger sized catch can are you guys using?

I'm looking around and don't see many options that are easy to install in my cramped engine bay running the twins and all the accessories.

Thanks.

Yes. I was also meaning to retain the stock plastic valve to the oil filter neck.

I will be using the Greddy catch can (when I get around to installing it).

http://mahjik.homestead.com/files/FD...eddy_parts.jpg

Mahjik - if you have some time, can you measure diameter and height on that Greddy can? Trying to figure out where I could mount something like that....

Thanks in advance.

Sure, I'll post them late tonight. I will be mounting mine in the area where my airpump used to be, basically in line with the stock oil venting line which ran to the primary turbo elbow.

I had the Gotham racing catch can and I couldn't for the life of me figure out where I was going to fit it in my cramped engine bay either... So I sold it.

Then I replaced my '93 filler neck with the RE-Speed baffled one, blocked off the breather line to the UIM, and figured that'd be that. The very next time I took the car out to an autox, not even a track event, under hard right cornering at near redline, oil particles started spewing out my BOV whenever I got off boost just like before. So now I guess it's time to reconsider that catch can. That or I've got residual oil built up in my I/C and it's coming out.

Sorry for the rant. I know it wasn't helpful at all, but I had to get that off my chest.

I'm planning to mimic Crispy's setup:

1. Baffled oil pan
2. ReSpeed baffled oil filter neck
3. Catch tank

I'm hoping that should do the trick, but we'll see here in about a month or so.

I put together a catch can made from a bicycle water bottle and bike mount. It's got one line going to what was the center drinking spout to the oil cap, and another line coming off the cap that goes to the turbo inlet. It's WAY better than the GReddy I tried, because the GReddy requires that you dissassemble the whole bloody thing to empty it. I was filling it ever run.

I fill the water bottle ever run too (similar capacity), but all I do is lift it out of the mount, unscrew the bottle, dump, replace.

Sounds like a great idea.

Can you post a picture of that setup?

Basically 7" tall, the base is 4" x 3" (kind of an odd shape).

Thanks Mahjik.

That is pretty odd. I'm going to poke around and see where something like that would fit.


Now that Peter posted, I remember seeing a pic of his setup but I can't find it in a search anymore. I'll try again later.

^^^^

It may not be the latest, I've made like 6-7... one used a bicycle bottle with a little K&N lawn mower filter on top.... I'll try and snap one of the latest and greatest.

Whats the purpose of the baffled pan? Ill be running a REW with 2nd gen pan and it currently has no baffle

Johny

^^^

It's to prevent oil slosh on hard corners, that results in it being sucked up and out of the oil filler tube with the "crankcase" pressure.

Found your pic you were talking about.
https://www.rx7club.com/showpost.php...65&postcount=3

I bought a JM Fab vent catch can listed here

http://www.maperformance.com/store/p...at=1368&page=1

Does anybody have a diagram of where this should be routed? I'm not really sure how to hook this up. I will be running a single turbo.

How did this unit workout for you?.

I have a hand built aluminum box sitting above the oil filler with AN-12 hose into the filler. The vent tube goes into the side of the can and it has a small breather to atmosphere on the front. While oil still gets pushed up in hard right hand corners it quickly drains back down once I straighten out. I used to fill two quart oil cans in about ten minutes before I built the drain back box. Now, no issues. I have a screw in AN 16 fitting the top of the box for adding oil to the engine.

-Trent

Sounds cool. Post up some pics. I'd love to see this.

I'm getting one of these:

https://www.rx7club.com/attachment.p...7&d=1203618024

From this thread:

https://www.rx7club.com/showpost.php...&postcount=708

It fits in the area formerly occupied by a vacuum chamber.

afgmoto1978 is fitting a vmount setup in my car, and I'm getting the custom catch tank as well. Oil will be routed back to the crankcase.

It's a pretty cool piece of fab work.

Cool but most sanctioning bodies require something of larger capacity. NASA says 1 quart. I know the 1 pint is a bit small and can fill up every session on some tracks.

Since it doesn't require emptying, why should it matter?