Oil catch can, would it be better with a breather?

[Sycostang67]

I'm sorry if this has been discussed in length, but you cant do a search for "catch can" because it splits the words and gives you tons of results that have nothing to do with what I need to know. I am preparing to change out my intake and want to add a catch can in-line with the CDR hose. Most of the cans I see use a pretty small hose, I think 5/16" was the biggest. I understand the worry of restriction in using a smaller hose and am wondering if using a catch can with a breather on it might help. I want to retain the CDR, run the hose to the can and then back to the intake to avoid the extra smoke caused by an RDT. I figured on stuffing the can with steel wool as well. Most of the cans I have looked at I can at least change the hose fittings to be a bit bigger, but I don't think I can get them as big as the current CDR hose.

I was looking at something like this...
http://www.amazon.com/Universal-Rac...qid=1395446931&sr=1-15&keywords=oil+catch+can

...or this kind with a breather.
http://www.amazon.com/DPT-DPT-OCT-A...ds=oil+catch+can+with+breather#productDetails

 

[79jasper]

http://ocnav.com/cars/oil_separator.html


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[CDX825]

Id stick with something closed. The breather one would end up being messy I'm sure.

Problem I see is you need one with at least 3/4" connections. Anything smaller and Id be afraid of over pressurizing the crankcase.

Maybe try making one out of PVC or ABS pipe

 

[drinkypoo]

The slickest catch can I ever saw was square, laser-cut and folded stainless, mig welded at the seams. With an internal baffle with holes in it, which also folded in before welding.

I have a metal cutter on my road and a MIG in my garage so I'd probably try to do something like.

A plastic can of oil hovering over the engine? What could possibly go wrong?

I'd stick with the 1" connections and I'd go to a muffler shop and have them make me something if necessary.

A GM CDR has a nipple out, easier for modding

 

[jaluhn83]

Ideally you want it to drain into the oil pan below the oil level - that would be the hard part since you need a tap into the bottom of the pan. The volvo gassers that I've worked with use an oil separator that's basically just a baffle with the narrow 180* bend - the idea being that air makes the turn and oil droplets don't, hit the bottom/condense and then drain back into the pan. One of my long term goals is to build something similar for the idi, but I haven't gotten that far yet.

 

[drinkypoo]

Any pressure drop will cause some oil to fall out of the air. I got a nifty upgraded crankcase breather hose for my 300SD, which runs from the top of the valve cover to an oil separator in the middle of the air filter housing. It has a serpentine path in it, which causes a whole series of little pressure drops. You'd need two or three of those rigs for the 7.3 though, and the oil sep is integral to the air filter housing. The air sep there is just a can with a drain in the middle, and a port back out of the top for the gases to flow up through and then down a little plastic pipe into the intake right before the turbo. Guess they wanted to make sure it stayed lubricated

 

[jaluhn83]

I'm pressure it's not the pressure drop, is the sudden change in direction. Pressure shouldn't have anything to do with oil mist in the air. A sudden change of direction will make it fall out, since the air can turn much quicker than the oil droplets can. Same reason centrifugal filters in heavy equipment, cyclone separators (sawdust separation for example) and steam separators on boilers all work.

 

[Sycostang67]

Id stick with something closed. The breather one would end up being messy I'm sure.

Problem I see is you need one with at least 3/4" connections. Anything smaller and Id be afraid of over pressurizing the crankcase.

Maybe try making one out of PVC or ABS pipe

That gives me an idea.

The slickest catch can I ever saw was square, laser-cut and folded stainless, mig welded at the seams. With an internal baffle with holes in it, which also folded in before welding.

I have a metal cutter on my road and a MIG in my garage so I'd probably try to do something like.

A plastic can of oil hovering over the engine? What could possibly go wrong?

I'd stick with the 1" connections and I'd go to a muffler shop and have them make me something if necessary.

A GM CDR has a nipple out, easier for modding

Some of this pipe should stand up to decent temps though right? I have no intention of mounting it near the motor, most likely on the inner fender away from heat or possibly in front of the core support.

 

[Sycostang67]

I went shopping today, PVC is only good to 140*, CPVC is good to 200* but unavailable in anything larger 1" diameter. I am now going to try some stove pipe which is good between 400-600*. The smallest and sturdiest I could find was a 6"x6" piece. I got two end caps for it. I will seal the hell out of the lower half with some leak testing before I toss it in. The top will clamp on and I will reinforce the roof with some extra metal to help hold the fittings and the baffle. I need to find some one inch 90* hose fittings now. I will hit up some fitting shops later this week.

 

[jaluhn83]

ABS or PVC should be fine. I used washing machine drain hose for a while and it worked ok though it would get soft.

The crankcase vapors aren't going to be that hot and they'll cool quickly. Ambient heat in the engine compartment is more of an issue.

There's very minimal pressure on the system (unless you have major issues) so all you need is something strong enough to support itself. Those temp rating on PCV are for pressurized service, ie hot water. In this application it'll be fine pretty much up to the point where the pipe melts which is something like 400+*.

 

[88beast]

ok well for refrence heres some pics of mine, and i have not gotten above the low line on the cans sight tube yet so it must be working, also no oil slick below. 100 miles or so on the setup ok no pics i dont think i have any, but running from the drivers vc up to the top of the firewall then to the pass fender is enough to have the oil drain back mostly.

 

[Sycostang67]

ABS or PVC should be fine. I used washing machine drain hose for a while and it worked ok though it would get soft.

The crankcase vapors aren't going to be that hot and they'll cool quickly. Ambient heat in the engine compartment is more of an issue.

There's very minimal pressure on the system (unless you have major issues) so all you need is something strong enough to support itself. Those temp rating on PCV are for pressurized service, ie hot water. In this application it'll be fine pretty much up to the point where the pipe melts which is something like 400+*.

Really, that would be great as I found the parts to make a really nice setup with the PVC. The stove pipe could be pretty good but was going to end up larger than I wanted. I plan to have the can mounted on the passenger side fender well, where the factory jack sits. I figured that would be far enough away from serious heat and I could always build a heat shield around it if necessary.

I was also planning on putting a baffle on the inside, like on the underside of a valve cover, just a plate with some holes in it. Would I still need to put steel wool in the container if I have the baffle or would both be better?

 

[Alacrity Machine]

I own AlacrityMachine. And i'm actually working on building catch cans that will work with the IDI cause i'd like one on my truck to. I'll have to post up a rendering. So what i want to do is potentially bolt the CDR valve direct to the catch can and then just run a hose straight to the CDR from the valve cover. From the catch can to the intake. Fairly basic setup. I'll post pics of the rendering if anyone wants to see. I wanna try and sell the whole kit even a fitting for non turbo valve covers to a 3/4 hose for like 150.00 I haven't quoted it all out though i might be able to go cheaper. Just saw this figured id give my two cents.

 

[RLDSL]

check out the Racor CCV It's made for diesels and has an automatic return in the bottom to drain back oil to the crankcase when not pressurized ( you can braze a nipple to the oil dipstick tube)

 

[Sycostang67]

I think I have everything I need to construct this thing. I have some 4" diameter PVC with a solid bottom cap and a female adapter top with a plug that I can remove should I need to clean the inside out. I have a small brass drain valve for the bottom and pipe fittings for the sides that will allow me to run 1" hose from the CDR and back to the intake. I also have some tin I will use to form a baffle. I will run this through my regular intake for now until I replace it in the next month or two. When that happens, all I should have to do is mount my extra 90* 1" elbow to the new intake pipe and shorten/lengthen the hose to accommodate it. I am hoping to get the majority of the work done this weekend.