Another legitimate Oil Catch Can question...
 

Hey all,

New to the site, but not to cars :thumbsup: I've been looking into what necessary adjustments need to be made to the 2010 Clubman S I just bought, and I'm seeing very clearly that oil catch cans are a must. I've read just about every thread, and I still have a few questions...

1. I want to do it once, and do it right. Do we need 2 separate cans, or will that boost tap system work? I don't fully understand the boost tap, does it prevent all flow through that line? I'd prefer to put an OCC in line and let the system work as intended. Am I wrong?

2. I want to do it right, but on the cheap if I can :lol: Looking at this can, are the inlet / outlet sizes enough for flow? They appear to be .5" (15mm). I know I'll have to find adapters to fit the stock hoses, but I'm concerned that it would add a restriction in the system.

3. Would either of these catch cans see boost pressure if used in conjunction with the stock PCV valves? I feel that the passenger side could be an issue in this regard.

I know this dead horse is sufficiently beaten, but I just can't make heads or tails of these two issues. Help?

Don't mean to spoil the party here but these catch cans are band aid solution to carbon buildup. What a huge waste of money. Catch cans are getting treated like they're a gift from God for the N14 and N18 engines when they catch only a fraction of the oil vapors in the crankcase ventilation system. I think one vendor is even charging over $239 for a kit. What a load of sh1t.

The best way to kill the problem is to convert your breather system to a vent to atmosphere setup. Not exactly legal and will fail a vehicle inspection, but it solves the problem. The only other way to alleviate the problem is to manually clean the intake ports/valves by hand or by doing a walnut blasting from time to time.

I'd have to agree with Shane: if you want to dress up your engine bay, get a catch can, but don't expect any true function from them.

Really? I get a lot of buildup in my OCC and have to empty it regularly.

So the issue is that this is really only a negligible amount of what actually gets passed the OCC and into the engine?

Yep.

I was afraid of that... I've been designing some wild oil baffling to go in one of those cans but I was afraid it would do no good. Besides, there's hardly any room under the hoods of these cars! I'm coming from a '99 A4 where there's room everywhere.

So, for a vent-to-atmosphere set-up... just hack both hoses in half, and put breather filters on the ends? I would probably route them down behind the block to not draw attention. If my thinking is correct...

- 1 line with filter from passenger valve cover port
- 1 line with filter from manifold port
- 1 line with filter from driver valve cover port
- 1 line with filter to intake port

Will this make my car smell? My A4 was catless, and I was looking forward to a non-stinky car!

Not good news. I thought all along I was saving my engine from massive carbon buildup.

So anyone care to elaborate in more detail on the vent to air fix? Is it easily reversible for inspection time?

This! I'm going to keep my stock hoses just in case. I really hope it doesn't make the car smell though.

I'm wondering the same, but having the OCC installed for over a year I can say that it made the car smell anyway so if the vent to air method actually works it's a good trade off.

I'm hoping that depending on where the hoses are routed that it won't smell worse than the odor added by the OCC when it begins to fill up.

How much of that is really just condensation? It looks nasty as hell, but water vapor will easily get burned up in the engine. That thin film of oil it catches is usually very small. I can't imagine all the gunk that can would collect in the winter with the large temperature difference between the ambient air and crankcase vapors. What a pain.

So did you just cap the manifold port and the intake port, and then run a line under the car from both sides of the valve cover?

I'd say that the jury is still out on this one. Just about every bit of information out there about OCCs is just opinion. I haven't seen one single documented report comparing rates of carbon build-up with and without an OCC. I want to see an OCC installed on a recently de-carboned engine with a follow up inspection after 20-30k miles. Of course, we can't afford to wait around a couple of years for the results. I know my BSH can traps a helluva lot of crap and that crap isn't getting to my valves. I also know that the can isn't catching everything; that would require something on the scale of a cryo trap! bikerbob951 is correct that all these cans could use some design improvement - I plan to increase the surface area in my can with some extra metal mesh. So, I can only say that, in my opinion, a good OCC is better than nothing.

As sensitive as this emissions system is to pressure/vacuum, wouldn't opening everything up to atmospheric pressure start throwing cells? Maybe adding a conventional PVC valve(s) would help. I'd love to see some serious discussion on this issue. I'd like to not have to spring for water/meth injection. fun fun fun

Jon in SC

I was wondering the same thing about throwing CEL codes... I wonder if placing a generic PCV valve in-line for both valve cover lines would help when venting to atmosphere.

There is already a PVC valve on the outlet to the intake manifold (built into the valve cover, so probably just need one on the turbo intake side. I was thinking about leaving my OCC in place (intake manifold port of valve cover is already blocked off with BSH dual-boost tap), venting the OCC to atmosphere through a conventional PVC valve, and blocking the vent intake to the turbo inlet pipe. This would prevent any oil from reaching the intake manifold and still be a little more environmentally friendly.

Jon in SC

True, a lot is water condensation but a lot is also oil. And agreed, it's a big pain having to empty it all the time but was something I was willing to do in lieu of severe carbon buildup.

If the amount of oil it's capturing is negligible in comparison to what still gets into the engine than I would agree it's not worth the hassle.

How is that determined though?

Attachment 160120

So here's what I'm thinking now. Don't make fun of my MS paint skills! At least I would be catching most of the gross stuff before it goes on the street. Two questions with this set up though

1. With two inlets and one outlet, will this cause a restriction in the system? I don't believe it will, but I have no idea. The line out would probably be 1"dia. to help with flow.

2. Both valve cover ports are connected to some sort of vacuum in their stock configuration. Will the absence of significant vacuum cause an issue in this set-up?

That is, essentially, what I plan to do (hopefully, this weekend).

1. I don't believe there would be any restriction. There's not much of a flow involved anyways, unless you had excessive blowby.

2. Absence of vacuum shouldn't be an issue. More conventional systems just rely on combustion induced pressure within the valve cover to expel vapor through the PVC. Lower flow might allow more condensation within the valve cover though. Probably a good idea to check under the oil filler cap ocassionally. Also, make sure your vent line terminates low, at bottom of engine. Good Stuff!

Jon in SC

Someone had mentioned water/meth kit: Isn't it true that SOME water is required for it to help in preventing carbon build up? Seems like most meth kit users end up with 100% methanol(different makes seem to respond to different mixtures but MINIs supposedly do best on 100%). And are we certain that it is going to prevent future build ups? I know that it won't clean what is currently present but how sure are we on future prevention? I'm in the midst of installing my Aquamist and going back and forth on mixture(planning on getting Jan to meth tune regardless)

I don't know about 100% meth usage, but I once used 80/20 meth/water in a Saab. When we removed the head to replace the head gasket, and after about 30k miles, the valves, pistons, and head looked like new.

Jon in SC

I'm glad I am not the only one saying this. As for the person with that MS Paint diagram, what are you using a catch can for? and the green PCV valves.

Have you read the entire thread? ......... Just sayin.

Really you are "just asking" if you are "just saying" the things you imply are not well... I'm sure you even know what you imply since you are using a saying that makes you sound like you have no idea what you are talking about. You are only saying it with no proof or knowledge of the thing you say.

I suppose I could of rephrased my statement to the following. "I'm glad that someone else who isn't a sheep agrees with me; it's nice to have another reputable form member on my side."

Also I bought an extra oil cap and I am going to tap it for pressure. Then we will have a better idea of what is happening.

In the olden days, cars had a Draft Tube that went from a space connected to the crankcase and led under the car, where the air passing under the car, flowing past the end of the draft tube caused a low pressure area that would help draw the crankcase gases out.

I've seen photos of owner's installations that had a filter or screen on the end of the vent to atmosphere. I don't think that would be a good idea as a screen or filter would not promote a low pressure and could get blocked by condensed oil or water.

Dave

I have an Aquamist and I'm running an 80/20 mixture. From what I understand the water provides the cooling benefit whereas the alcohol provides pre-detonation and cleaning benefits.

I know some run 100% methanol but most Mini owners run a mixture.
You'll get the best benefits by having it custom tuned as you're planning to do.

The diagram looks good to me, then again I just now learned about the vent to air method.

It doesn't have to be a catch can but the BSH has an outlet at the bottom so if you already have one you'd only have to add a connector there and then a hose.

The check valves would prevent back flow.