Thankfully that other horrible thread was locked by DiD. I posted with a reasonable question that was completey ignored by those who had hijacked it.
Here's my question:
Am I doing any damage, or losing some performance if I install my catchcan as per the M7 installation guide and cap the grey line coming from the supercharger?

thanks

 

Careful, your new thread might get hijacked as well....

On a more serious note (in particular, about your question), you may create some problems with the emission control system if you cap off the grey line. I don't know for sure, since I have not done a before and after SMOG test (and I won't, because if the car fails the test, then a flag gets set in the DMV file for my car and all kinds of misery ensues), but that is what immediately comes to mind.

Hope your thread doesn't get hijacked, though.

 

This may help with the debate. Based on it's placement in the induction path there will be lower pressure here than the other pickup point that is ahead of the throttle body. Under conditions other than WOT you will get better venting than from the location pre-TB.
There was mention of a check valve in this grey line. Does anybody know where? The PCV valve does exactly that so are there 2 such valves or what? I'm not quite clear on this one.
My 2¢ is I'd rather leave this tube operational since it is; A. directly linked to the PCV and B. under a lower pressure environment.
Will capping this off do harm? I don't know but I do know that the PCV will not function as well.
So far everyone has "T"d in the other vent line post PCV. Has there been any consideration for doing it pre PCV? You could then cap off the inlet in the airbox to TB tube.



Compliments to jlm for the pic and leaving it up so it isn't a broken link

Hijacked?

 

obehave:
I was thinking along the lines of your last question: Could we come up with a OCC venting path that used the vacuum in the grey line rather than from the inlet tube pre-TB? We could cap or plug this line, and still have the gases being drawn out of the tappet cover, through the OCC and back into the system via the grey line.
I sketched a diagram of the routing Im thinking of (please excuse the drawing--I just got my tablet and this is my first attempt at drawing with it!):


Cheers,

 

Just looked at this a little closer.
"So far everyone has "T"d in the other vent line post PCV. Has there been any consideration for doing it pre PCV? You could then cap off the inlet in the airbox to TB tube."
Doing this pre PCV would be a PITA.

The routing would be simple. A "T" in front of the PCV. The vertical leg to the PCV, the right side from the vent side of the valve cover, the left side going to the inlet of the OCC. The outlet of the OCC to the grey tubing.

I do have to wonder though why it is routed the way it is.

 

Aren't you describing what I have drawn (poorly, I know, sorry)? You would cap the take-off from the inlet tube pre-TB?
And just to be clear, the PCV is the fitting in the valve cover on the left side near the "MINI" badge?
cheers,

 

That's odd. I didn't see the drawing at work when I posted

Now I do. But yea, that's what I was yapping about.

 

This is a nicer thread.

 

I think I've said this in the last thread, but I think it got lost in the off-topic postings. The grey line pulls vacuum out of the valve cover, thru the PCV valve. If you connect your OCC as you describe in the picture, then you should be fine as long as you don't use the collapsable tubing as supplied by ALTA. Find some tubing that wont succumb to the vacuum, and also made of a material that won't be degradable by the vapors and oil.

 

gandini, This is a good way to have it hooked up. After the last thread there was no way to state the simple but elegant. Another way is to connect to the PVC, to the can, to the grey line. This way there is some crankcase relief ( It does need air ). That's why the air filter is used. If no air is available you may find more oil in the OCC because there is no air to displace the movement in the lower end. IMHO this is the best way to hook up an OCC..... I've been wrong before...

Thank you, Thank you, Thank you.

 

I agree with all that.
gandini, a picture is worth one thousand and one words on NAM thanks.

 

Deleted.

 

Thanks for your help!

gandini, thanks for taking your time to draw the picutre. It is EXACTLY what I was looking for on page one of the "last" thread.

The OCC is on the to do list.

 

I re-installed my M7 OCC today--from the M7 routing to the one I sketched. I will report how it goes as I commute this week. It's a little neater, as you don't have two lines going underneath or behind the IC, just one from the RHS breather.
chuckt: I am concerned about pulling vapor from lower down in the crankcase, and am considering going back to the setup you suggest. This is the neatest line setup also

Cheers,

 

If you leave the breather alone ( from the VC to the intake ) there is a baffle to prevent oil from being sucked out by the intake. The bottom end needs air, after all it is a big pump...

 

Deleted.

 

One thing being forgotten in the discussion here is the fact that you're not venting the valve cover. You are venting the entire engine. The main reason for this venting in the first place was that with the engine totally sealed you will build up positive pressure and this needs to be relieved.

There is always blow by on the compression stroke no matter how good the rings seal.

Here's a good read which reminded me of why I chose the routing I did for my OCC.
Which leads me to agree with some post sfrom a while back that running 2 OCCs is another viable option and may be the better plan.

 

Deleted.

 

Your crankcase isn't under a vacuum.
I wouldn't seal off the breather. Like it's name denotes it breathes so at different times it's either under positive or mild negative pressure.
Mostly positive which would be the reason for the baffle in the valve cover than and the fact that a lot of oil splashes around in there

Even pre PCV days there was an inlet breather and a vent tube. Spewing crap into the atmosphere

The link I posted earlier explains this much better than I can.

 

It is not a good idea to seal off the breather. BMW, or for that mater, no manufacturer seals the engine. Eventualy a seal or a gasket will fail.The original "OCC", now dead, thread addressed this problem with the 2 can set up. IMHO you don't need a second can to collect vapor. Most VC after market breathers ( drill holes in the cover - bolt on to the cover are a rare find today - even they had baffels ) are hardley wet after heavy use & you will hardley notice much wet on the intake tube on your mini.

 

Deleted.

 

Look I'm really not trying to argue but this point needs to be clear. The crankcase is not under negative pressure. Read the link again.
Yes there is negative pressure on the grey line. That negative pressure it strongest at idle. At this time the PCV is closed. The PCV flows the most gas, from the crankcase but into the induction path, at WOT when there is the least amount of negative pressure in that grey line ( basically none since you're really at or darned near atmospheric).

There is no time that I have ever heard of the crankcase being under negative pressure. Maybe, just maybe, a defective PCV could cause this but I am assuming we are discussing properly functioning components.

I am agreeing that the breather needs to be open, no debate there.

 

I wanted to be clear here. I am only talking about the grey vacuum tube. The line to the driver's side should not have been included in my definition The tee to tie the lines together should not be done. Again, as I stated in the "other" thread, the two occ installation as shown in its first post would be the preferred setup.

Another thing to throw into the mix, is that if you're twin-charged, then you're supplying pressurized air to the grey line (from the pre-supercharger side). Again, if you choose to tee the lines together, this would then pressurize the valve cover area by bypassing the one-way valve. Not a good situation.

Without an OCC installed, I watched closely as my car ran numerous times on the dyno with the twin-charge setup. At the higher PSIs, the valve cover area really pushes out a tonne of vapor. When I first saw it I thought something was wrong such as an major exhaust leak, or a blown seal etc. But I was informed by Hubie, that it is quite normal for some the combustion chamber gasses escape along the valve shafts into the valve cover area. Then being blown to atmosphere (what I saw) thru the driver's side valve cover vent line.

 

I must be brain dead on this issue, but do I understand that we should be 1) replumbing the OCC to match gandini's hand drawn picture as a better option from the one Alta suggested and 2) in a perfect world we would want to do 2 OCC's

Thanks

 

1= No
2= Yes

JMO


Further debate to follow