Homemade Catch can or RRE?

[ryanx99GS]

Okay, I have searched on the subject of using a catch can or not. But, there are so many mixed opinions/solutions to it that I don't know which one to do. The home depot version, the RRE, Greddy, or running 2 cans. Which one is the best for me? The car is my DD and what I have done as far as mods is in my profile. I plan on sticking to the T-25. Thanks for the help and advice.

 

[VETTE_50_TH]

Makes sense. Look at the top of the can, and you can see screws.

James

 

[Calan]

I fabbed up a bracket and mounted a 1/4 turn drain valve down on the passenger-side frame. A hose runs from the can to the top of the valve, and then a short one hangs out the bottom. So I can just slide the pan under it and drain it when I change the oil.

Here's a pic:

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[VETTE_50_TH]

Very ingenious. Wish i had that kind of time. And knew where to get those parts.

James

 

[HighBoostLaser]

Or the bolt that holds the metal to mount it?

 

[Calan]

Which parts (James) and which bolt (HighBoostLaser)?

You guys lost me... and I'm not even drinking tonight

 

[VETTE_50_TH]

The part is that nifty looking drain valve and tube you got there. Looks cool. One day, i'll do something like that. It cool seeing different ideas for the same thing. I have no idea what bolts hes talking about either.

James

 

[Calan]

The drain is just a 1/4" MPT/FPT brass drain valve from a hardware store. I made the bracket from a piece of scrap aluminum angle, and sandwiched it between the valve and a brass 1/4" FPT barbed fitting (I used a thin nylon washer as a spacer to get it to tighten up properly). The other side of the valve has a 1/4" MPT barbed fitting screwed into it.

The bracket is mounted to the frame using a couple of 6mm bolts and lock washers.

That's about it... not much to it

 

[kenamond]

Although those catch cans are cheap and I assume they are air-tight, they're HUGE (if you take the dimensions listed, that's almost a quart!) I would be astounded if you actually needed something that big (filling both of them up would drop your oil level by two quarts out of 4.5 total). But that *is* a much better price than I've ever seen. I think the ideal can would be the size of those Husky or Kobalt compressor filters.

Another thing I'm unclear about is whether the oil is a mist. If so, you need some sort of filtering media or you pull the mist right through the catch can and it still makes its way into your intake. And that eBay can doesn't say it has a filter. Might be able to pull the top cap off (I see screws) and drop some filter media in there like some steel wool or something. I dunno.

 

[ryanx99GS]

How about this?

eBay Motors: GMAN Oil Catch Can Stock & ModifiedGo Kart Racing (item 110209022174 end time Mar-26-08 10:07:16 PDT)

I am putting in a new motor in about a week and thought while doing that I can find a spot to mount this catch can. Has 4 input so...
Would that work?

 

[kenamond]

It has a breather, so it won't work (correctly). The catch can has to be sealed: one inlet, one outlet. Otherwise, you suck in unmetered air or breathe out metered air. And you need one can for the VC breather line and a separate can for the PCV valve line (can't combine them unless the can is completely divided into two chambers and two pairs of in/out nipples). I think the VC breather line is more important as far as filtering oil, so if you're going to get just one, I'd get one for that line.

 

[Icarus]

(corrected drawing)

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I've been thinking about this for ever since I saw Calan's drain tube design. I had a idea for cheap simple solution to this problem. Why not instead of buying catch-cans just use tubing for the whole setup and save some space.

Place the Tees and a few inches of tubing vertically on the firewall, or wherever then plumb the returns complete with check valve. Set up the drains like Calan's set up. If the drain lines were 3 feet long transparent tubing and 1/4" ID the capacity of the drain tube would be 8.2 tablespoons if it's 3/8" ID then the capacity would be 17.6 tablespoons.

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Depending on how much goes through the system and how often you want to drain it you can vary the size of the tubing. Personally I'm going to give the 3/8" tubing a try, it should be more than ample for my setup if I want to drain during oil changes.

 

[silver bullit]

Dude that is not gonna work.

The lines are still seeing vacuum in a closed a-b vacuum circuit, its like plugign to lines to each is all you are doing youll get the same result as a stock setup.

You need a setup where a canister can hold oil and still bleed the oil from the lines while it is not interrupting the air flow that is what a catch can does, if you still dont understand then thats you fault.

 

[Icarus]

Dude that is not gonna work.

The lines are still seeing vacuum in a closed a-b vacuum circuit, its like plugign to lines to each is all you are doing youll get the same result as a stock setup.

You need a setup where a canister can hold oil and still bleed the oil from the lines while it is not interrupting the air flow that is what a catch can does, if you still dont understand then thats you fault.

Wow harsh!

I think I understand the design but feel free to correct me. You think that there will be enough oil in the lines from the VC that it will block any movement of air through the system. If that were true, then using traditional catch cans would suffer the same problem. Since the PCV valve is a metering orifice, as long as the size of the tubing is larger than the orifice then there would be no problem .

The only difference between what I propose and the dual catch can design I tried to orignally quote from Calan's post is the shape of the catch can. The other difference, from what I've seen advertised on the web, is the addition of a filter in the catch can which can be replaced by an inline filter on the return line. My idea uses the the drain tube as the catch can instead of a chunk of overpriced metal. The only way I see the system failing is if you blow a tablespoon or more everytime you get on the boost.

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But again I could be wrong. If I am wrong please explain it to me. I read the forums to learn. Personally I don't need some extra polished aluminum in my engine bay I'd rather keep things cheap, simple and occupy the least amount of space .

 

[kenamond]

I think that you have to filter the vapors, but I'm not positive. If oil comes through as large droplets, then maybe you don't need filter media in the can, but I keep reading things calling it "vapors" and saying it will "condense" in the intake.

What I think would be ideal for the VC breather catch can would be to have a can, and the line from the VC would extend to the bottom of the can, and the line to the intake pipe would just connect at the top. And there would be filter media filling the can. That way, when the blowby is spewing oil into the can, it gets filtered and settles in the bottom of the can, but when you idle and the flow reverses direction, the tube to the VC that is at the bottom of the can acts as a siphon and actually pulls the oil back into the VC. In that case, you may never fill up the can. I'd draw a nice picture, but I'm feeling quite the lazy bastard this fine Sunday.

 

[turboglenn]

I'm thinking that your going to fill that tbe up really fast. When my PCV valve went out i was blowing a half cup of oil out everytime i hammered on it with boost over 9psi. If you're wanting to stay on a budget, just do like we do on our motard bikes. Get you a small piece of PVC pipe (2'' diameter) and 2 end caps for it. make yourself a small sealed can out of the three pieces of PVC, then add some fittings to it. One for suction from the turbo on the intake, then one from the VC to the can. make sure the 2 lines are seperated good enough that you're not going to suck oil straight from one to the other. There's several ways to do that.My favorite way is accomplished by making the line from the VC extend into the can (from top facing bottom) and then having the one making the suction/vacum just mounted flush at the top of the "can"(again facing down), that's the easiest way i know of.

 

[kenamond]

I'm thinking that your going to fill that tbe up really fast. When my PCV valve went out i was blowing a half cup of oil out everytime i hammered on it with boost over 9psi. If you're wanting to stay on a budget, just do like we do on our motard bikes. Get you a small piece of PVC pipe (2'' diameter) and 2 end caps for it. make yourself a small sealed can out of the three pieces of PVC, then add some fittings to it. One for suction from the turbo on the intake, then one from the VC to the can. make sure the 2 lines are seperated good enough that you're not going to suck oil straight from one to the other. There's several ways to do that.My favorite way is accomplished by making the line from the VC extend into the can (from top facing bottom) and then having the one making the suction/vacum just mounted flush at the top of the "can"(again facing down), that's the easiest way i know of.

But with a properly functioning check valve on the PCV line (either good PCV valve or separate check valve), you don't have to worry about that; you just have blowby pushing fumes out the VC breather. I've been thinking of the PVC pipe/caps idea, since anyone could fab that up. Paint it black and fab a bracket and be done with it for a few bucks.

 

[turboglenn]

I'm not saying do one thing over another for any reason, i just explained how we build catch cans for our motard converted dirtbikes when we race indoors. If you feel you don't need a catch can, don't use one. I like them, i use them, but i won't pay 80-100 bucks for one, so i'd rather make it from supplies i can get at home depot. And yes, if the PCV is good it won't blow a ton of oil out any of the lines unless you've got massive blow by. But last week when my PCV valve went bad i was blowing at least a half cup of oil out everytime i got on it.

 

[kenamond]

I'm not saying do one thing over another for any reason, i just explained how we build catch cans for our motard converted dirtbikes when we race indoors. If you feel you don't need a catch can, don't use one. I like them, i use them, but i won't pay 80-100 bucks for one, so i'd rather make it from supplies i can get at home depot. And yes, if the PCV is good it won't blow a ton of oil out any of the lines unless you've got massive blow by. But last week when my PCV valve went bad i was blowing at least a half cup of oil out everytime i got on it.

Chill dude . I like the idea of a cheap catch can. I was just saying that if folks get their PCV valve fixed, they won't have to worry about quarts of oil going into the intake. Actually, I'm trying to get my kids ready so I can go to the hardware store and get what I need to make a PVC can. I have a design in mind that I think will work well and be about as cheap as you can get.

 

[turboglenn]

Chill dude . I like the idea of a cheap catch can. I was just saying that if folks get their PCV valve fixed, they won't have to worry about quarts of oil going into the intake. Actually, I'm trying to get my kids ready so I can go to the hardware store and get what I need to make a PVC can. I have a design in mind that I think will work well and be about as cheap as you can get.

Sorry i didn't mean to sound rude or pissed off. I was just in a hurry to get out the door and go get lunch. You're right, with a good working PCV you won't have a ton of oil spewing out of the motor. I was just trying to tell people how to make one cheap that actually works instead of trying to be SUPER CHEAP and not even having any type of can for your can if you catch my drift. Although not pretty, the PCV catch can has served me good for years on end. I actually use the same one on one of my bikes, i swap it from the car to the bike before I load the bike in the truck and go. Then when i get home and unload the bikes i just throw it back in the car

 

[Icarus]

I was basing my capacity off the S2000 site linked somewhewre in the "stupid PCV" thread. It was talking about the Husky catch can and I think he stated that he blew a tablespoon a week. I was not thinking 1/2 cup at a time, Mobil must love you. I don't think I'm having that severe of problem, but I think it's time to go down and look at some HD Performance parts and see if I can make something in between my idea and a traditional catch can (maybe PVC).

 

[gorf]

I'm thinking that your going to fill that tbe up really fast. When my PCV valve went out i was blowing a half cup of oil out everytime i hammered on it with boost over 9psi. If you're wanting to stay on a budget, just do like we do on our motard bikes. Get you a small piece of PVC pipe (2'' diameter) and 2 end caps for it. make yourself a small sealed can out of the three pieces of PVC, then add some fittings to it. One for suction from the turbo on the intake, then one from the VC to the can. make sure the 2 lines are seperated good enough that you're not going to suck oil straight from one to the other. There's several ways to do that.My favorite way is accomplished by making the line from the VC extend into the can (from top facing bottom) and then having the one making the suction/vacum just mounted flush at the top of the "can"(again facing down), that's the easiest way i know of.

That is basically what I did but I used a 8 inch long piece of 1 inch pvc. With just open lines, I still got oil in my intake. You need to add some filter material to the inside top so the vapors hit something and condense. I also used a pvc cap on the bottom so I can drain the oil out.

 

[kenamond]

I was basing my capacity off the S2000 site linked somewhewre in the "stupid PCV" thread. It was talking about the Husky catch can and I think he stated that he blew a tablespoon a week. I was not thinking 1/2 cup at a time, Mobil must love you. I don't think I'm having that severe of problem, but I think it's time to go down and look at some HD Performance parts and see if I can make something in between my idea and a traditional catch can (maybe PVC).

That is basically what I did but I used a 8 inch long piece of 1 inch pvc. With just open lines, I still got oil in my intake. You need to add some filter material to the inside top so the vapors hit something and condense. I also used a pvc cap on the bottom so I can drain the oil out.

I got a threaded PVC coupler (maybe 1"ID?), two threaded end caps, and two 5/16" barb fittings. I'm not sure of the exact part names, but the coupler has a hex shape molded into the midsection, and both end caps have hex heads. I also picked up a small sheet of aluminum to make a bracket. I plan on drilling the two end caps much like a BLTer and threading the fittings into the end caps with a dab of RTV on the threads. If the threads of the caps don't seal well enough to the coupler (oil leaks out), then I'll seal with RTV or grease or something. This is for the VC breather, so it never sees much pressure, and I only care about oil leaking. The unit will mount vertically, and the VC breather line will go to the bottom and the intake pipe line will go to the top. I'll stuff it with 000 steel wool. The bracket will hold it vertically and probably screw into the flat face of the top endcap; the bracket will "fork" around the fitting and screw into the cap with a few screws.

When you're idling, the lower hose will be sucking. If there's any oil in the can, it should suck it back into the VC. I'll test this out by starting off with the can half-full of some Mobil 1, start the car, let it idle for a handful of seconds, then check the level of the can. If that works, the volume of the can might not be an issue...you just need enough volume that shifting or otherwise letting off the throttle can drain the oil back to the VC.

Anyway, that's all on the drawing board, so I don't know what snags I'll run into.

 

[dalatinromeo]

The Stupid PCV Valve Thread is too long for me to read I read like 3 pages and stopped.

And maybe I missed it here, so whats the answer, which is better a homemade or a professional one like from RRE??

 

[kenamond]

The Stupid PCV Valve Thread is too long for me to read I read like 3 pages and stopped.

And maybe I missed it here, so whats the answer, which is better a homemade or a professional one like from RRE??

As long as the catch can is sealed (one input, one output), has filtering media, and doesn't leak, homemade is fine. It might not look as pretty, though, but that depends on how you make your own, what you make it out of, whether you paint or polish it, etc. And it has to withstand fuel and oil (on the inside), heat (throughout), and water (on the outside) without deteriorating/cracking/corroding.

 

[gsxtasy]

I'm interested in your results Mack, keep us posted, and maybe a pic of the finished product?