[Chefcg1]

Oil Catch Can idea similar to ar design.
This is by no means a bash or even a comparison to their unit. I’m just offering what I think is comparable unit at a much more reasonable cost.
This OCC idea was put together after my search for a quality reasonably priced unit to install along with my resent purchase of a Helix IC. I have used several different units over the years in various vehicles that I have owned and always went back to my home made unit after the purchased units leaked. During my search I came along the new ar design OCC unit that has been recently introduced. I noticed from the pictures on their web site and noticed that it looked just like the units I used to make. I want to say again this is NOT a bash of ar design’s OCC. I just wanted to give the BMW enthusiasts a quality cost effective alternative.
The parts:
OCC= Schrader Bellows 3/8” Pneumatic air filter. Cost free (I have had this sitting in its box for probably 8 years and had forgotten about it.) Alternatives would be pretty much any 3/8” Pneumatic air filter from companies like Parker or Wilkerson. They range in price from $29-$75, but all pretty much have the same 5 micron filter and do the same thing. Lots of good choices on eBay and if you can’t wait Sears and Home depot offer them.
¾” to ½” reducing coupling (McMaster.com, 5047K28, $2.33)
1” to ½” reducing coupling (McMaster.com, 53055K147, $4.27)
2X Brass 90deg. Elbow, ½” hose ID X 3/8” NPT Male Pipe (McMaster.com, 53525K21, $7.11)
1’ of ¾” Heater hose (Advance Auto Parts, $1.49)
1’ of 1” Heater hose (Advance Auto Parts, $1.69)
2X 6’ Heater hose ” Heater hose (Advance Auto Parts, $11.18)
6x #12 hose clamps (fits hoses ½ to 1 ¼”) (Advance Auto Parts, $6.87)
My total cost $34.94
If you have to purchase a pneumatic filter for aprox $50 your total cost is still around $85.
I have not installed mine yet as I’m waiting on the delivery of my IC today and some warmer weather. With the amount of hose I purchased I have plenty of mounting options and I will update with Pictures when I do the install.

[ar design]

Originally Posted by Chefcg1

Oil Catch Can idea similar to ar design.
This is by no means a bash or even a comparison to their unit. I’m just offering what I think is comparable unit at a much more reasonable cost.
This OCC idea was put together after my search for a quality reasonably priced unit to install along with my resent purchase of a Helix IC. I have used several different units over the years in various vehicles that I have owned and always went back to my home made unit after the purchased units leaked. During my search I came along the new ar design OCC unit that has been recently introduced. I noticed from the pictures on their web site and noticed that it looked just like the units I used to make. I want to say again this is NOT a bash of ar design’s OCC. I just wanted to give the BMW enthusiasts a quality cost effective alternative.
The parts:
OCC= Schrader Bellows 3/8” Pneumatic air filter. Cost free (I have had this sitting in its box for probably 8 years and had forgotten about it.) Alternatives would be pretty much any 3/8” Pneumatic air filter from companies like Parker or Wilkerson. They range in price from $29-$75, but all pretty much have the same 5 micron filter and do the same thing. Lots of good choices on eBay and if you can’t wait Sears and Home depot offer them.
¾” to ½” reducing coupling (McMaster.com, 5047K28, $2.33)
1” to ½” reducing coupling (McMaster.com, 53055K147, $4.27)
2X Brass 90deg. Elbow, ½” hose ID X 3/8” NPT Male Pipe (McMaster.com, 53525K21, $7.11)
1’ of ¾” Heater hose (Advance Auto Parts, $1.49)
1’ of 1” Heater hose (Advance Auto Parts, $1.69)
2X 6’ Heater hose ” Heater hose (Advance Auto Parts, $11.18)
6x #12 hose clamps (fits hoses ½ to 1 ¼”) (Advance Auto Parts, $6.87)
My total cost $34.94
If you have to purchase a pneumatic filter for aprox $50 your total cost is still around $85.
I have not installed mine yet as I’m waiting on the delivery of my IC today and some warmer weather. With the amount of hose I purchased I have plenty of mounting options and I will update with Pictures when I do the install.

Looks nice. Just FYI, that filter probably flows right around 80-100CFM, nowhere near what the engine needs...... These things have a LOT of PCV flow....

[Chefcg1]

Originally Posted by ar design

Looks nice. Just FYI, that filter probably flows right around 80-100CFM, nowhere near what the engine needs...... These things have a LOT of PCV flow....

what is the recommended cfm flow?

[ar design]

Originally Posted by Chefcg1

what is the recommended cfm flow?

A lot more than a 3/8 setup like that can flow FWIW, there are very few 3/4 setups that even flow enough.....

[Chefcg1]

Originally Posted by ar design

A lot more than a 3/8 setup like that can flow FWIW, there are very few 3/4 setups that even flow enough.....

I’m a little confused and I’m not trying to start a debate, but just trying to understand better. You are saying because the inlet on the pneumatic filter is 3/8” npt that it doesn’t flow enough cfm? From what I have seen on most OCC that is more than enough. We are reducing a 1”line to ½” on one side and then a ¾” to a ½” on the other. The line going into the filter is ½” hose and we know that the inside diameter of ½” hose is actually smaller than the inside diameter of 3/8 pipe. Pretty much all the catch cans I have seen are ½”inlet and outlet and some smaller like the Riss & Mckinney. So if I understand you right you are saying those are no good or do not offer he CFM flow needed?

[JoeyFiasco]

Originally Posted by ar design

A lot more than a 3/8 setup like that can flow FWIW, there are very few 3/4 setups that even flow enough.....

if that's the case, a lot of people with the Riss Racing can are going to be pretty pissed..

[ar design]

Originally Posted by Chefcg1

I’m a little confused and I’m not trying to start a debate, but just trying to understand better. You are saying because the inlet on the pneumatic filter is 3/8” npt that it doesn’t flow enough cfm? From what I have seen on most OCC that is more than enough. We are reducing a 1”line to ½” on one side and then a ¾” to a ½” on the other. The line going into the filter is ½” hose and we know that the inside diameter of ½” hose is actually smaller than the inside diameter of 3/8 pipe. Pretty much all the catch cans I have seen are ½”inlet and outlet and some smaller like the Riss & Mckinney. So if I understand you right you are saying those are no good or do not offer he CFM flow needed?

Originally Posted by JoeyFiasco

if that's the case, a lot of people with the Riss Racing can are going to be pretty pissed..

A proper filter and a cannister with virtually no proper filtration are two totally different things....

[Chefcg1]

Originally Posted by ar design

A proper filter and a cannister with virtually no proper filtration are two totally different things....

So what is not a proper filter and not a proper canister? 5 micron filter is the same spec that you advertise? The cfm flow should be comparable to any 1/2" hose setup and a canister is just a canister as long as it can hold up to the environmental conditions that are needed without leaking. So what I'm gathering is that your OCC has better flow due to? Your 5 micron filter flow more than mine? Your hose diameter is larger?
I’m not trying to be difficult, I’m just trying o educate myself and get a better understanding of what is needed to make or purchase a safe OCC without beating around the bush and just stating the facts.

[R1000K3]

I think the use of a 5 micron filter is not needed and also introduces as risk. In case the filter is saturated with oil, which it probably always will be, it will become a huge restrictor during low temperatures when the oil in it is cold. That is one of the reasons I discarded the filter in my solution. The air compressor filter can will collect oil good enough without the use of an internal filter by the way it is designed.

[Chefcg1]

Like a said before this is not a bash on ar design and after reading back some of my posts it may seem that way. That is not my intention at all. I’m sure they put out a quality product.
What I intended to do was give a cheaper DIY option for all of us, but I do not want to propose something that is dangerous to our engines and from what I’m gathering from ar design’s comments is that what I have proposed is not sufficient thus not safe. So if anyone can shed some light on the facts of what is needed to have a safe OCC please chime in.

[Chefcg1]

Originally Posted by R1000K3

I think the use of a 5 micron filter is not needed and also introduces as risk. In case the filter is saturated with oil, which it probably always will be, it will become a huge restrictor during low temperatures when the oil in it is cold. That is one of the reasons I discarded the filter in my solution. The air compressor filter can will collect oil good enough without the use of an internal filter by the way it is designed.

I have considered that myself and I agree.

[ar design]

Originally Posted by Nick.CBR

AR,

What do you guys deem as the proper flow (in CFM) as well as the proper filtration process? This answer really doesn't really address either?

Thanks!

Nick

Frankly, not too keen on giving away hours and hours and hours of research.... I have to make a living here Bottom line - not all filters are created equal

[Chefcg1]

Originally Posted by ar design

Frankly, not too keen on giving away hours and hours and hours of research.... I have to make a living here Bottom line - not all filters are created equal

fair enough. I'm not here to take away your bread and butter.

I will go ahead with my project and let all those who are interest know how it goes and if I have any flow issues.

[raceyBMW]

From the other forum, Terry has said flow rate is ~200CFM at peak boost, which is pretty significant. Obviously it will vary from car to car depending on how well your piston rings seated during break-in.

[F104]

a 3ltr NA aspirated engine at 6000 rpm WOT pulls in less than 1.5*100 =150 ltr/sec. That is about 300CFM.
Back to metrics so i don't need a calculator: that 1% is 1500cc/sec in 3/4" hose (about 3 cm2) gives 1500/3 = 500 cm/sec= 5m/sec = about 18 kph = about 12mph airspeed in the 3/4" breather hose. Even that looks too high to me, so breather flow is likely 2CFM or less at max rates.

[invariant]

Originally Posted by F104

a 3ltr NA aspirated engine at 6000 rpm WOT pulls in less than 1.5*100 =150 ltr/sec. That is about 300CFM.
Back to metrics so i don't need a calculator: that 1% is 1500cc/sec in 3/4" hose (about 3 cm2) gives 1500/3 = 500 cm/sec= 5m/sec = about 18 kph = about 12mph airspeed in the 3/4" breather hose. Even that looks too high to me, so breather flow is likely 2CFM or less at max rates.

So, for an FI engine at 14.7 psi boost you are moving approximately twice as much air (absolute pressure is doubled: 2 atm vs 1 atm), right?

[scheherazade]

This pertains to the crank case pressure, on the *other* side of the piston... the one *without* the bang.

Bore & stroke & cylinder_layout will give you the change in volume along a single cycle.

RPM will determine how many times you see that change in volume.

-scheherazade

[F104]

Im interested in a OCC as well but nothing exists for a 320d.

I just wanted to calculate what reasonable breather flows could be. If you leak 10% of your intake airflow then it's safe to assume you have a hole in at least one piston. So i based it on 1% of intake airflow, and then did a theoretical check if airspeeds in a (3/4" ID) breather hose would not be riculous. You don't expect 100mph in that hose.

Not many cars have 3/4" ID breather hoses so based on this exercise i think it is fair to assume 1% of intake flow at max rmp WOT is already too high for an engine in good condition.

When it come to boost pressures this won't be a simple linear calculation, and i don't have a good answer. I take a diesel with 1:18 mechanical compression ratio running at 35 psi (absolute) boost will have more leakage past the piston rings than a NA engine running at 1:10 compression ratio at 14.7 psi atmospheric pressure.

[Chefcg1]

Originally Posted by F104

a 3ltr NA aspirated engine at 6000 rpm WOT pulls in less than 1.5*100 =150 ltr/sec. That is about 300CFM.
Back to metrics so i don't need a calculator: that 1% is 1500cc/sec in 3/4" hose (about 3 cm2) gives 1500/3 = 500 cm/sec= 5m/sec = about 18 kph = about 12mph airspeed in the 3/4" breather hose. Even that looks too high to me, so breather flow is likely 2CFM or less at max rates.

so if I understand you correctly 80-100cfm flow is more than acceptable?

[Chefcg1]

I have gone back and looked at the photos on ar designs web site and it is obvious they are stepping down in size from the 1" and 3/4" hose. The logical step down would be to 1/2" hose like most others are using and myself. With that in mind using a housing that has a 1/2npt openening over a 3/8" npt opening would only net you a max 20 more scfm.
at 100psi. This link is to a page that has a comparrison of some standard filters http://www.mcmaster.com/#frls/=5w0t9r

I just can't think of any way that ar is getting 200cfm through the same size line.

[F104]

Yes i would say that is about 50 times the max cfm (as in cubic feet a minute) it would see. On the other side you do want to to slow down airspeed thru the filter, to maximize oil filtration.

But i also agree with the comment someone else made, a filter in cold weather is going to cause one hell of a restriction when coated with cold oil.

So what I have in mind: Looking at getting a cheap any car cabin radiator core instead. Great cooling of hot gasses, lots of condensation surface for the oil, and no filter which can block. Just needs a mod to drain the oil on the outlet

[raceyBMW]

This is what I was looking to get after I saw R1000K3's setup with the breather. I already have the breather on my car, but I don't think its the best solution as you have to empty the hose pretty often because of oil build-up.

http://cgi.ebay.com/ws/eBayISAPI.dll...m=300349294844