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Werthers
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All DI engines have the same adverse effects of carbon buildup.
Not entirely true...

I mentioned the word "excessive" in my previous post as that is the issue with some of the BMW MINI DI engine in particular the early models... cars eating their engines after 20,000 miles is not normal and not all DI engined cars do this, quite a few early R56s have, Keano's has done it twice (luckily under warranty for both).

Pretty sure you or someone else already mentioned other car companies have found solutions to this.
 

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Themis
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Discussion Starter #362
Not entirely true...

I mentioned the word "excessive" in my previous post as that is the issue with some of the BMW MINI DI engine in particular the early models... cars eating their engines after 20,000 miles is not normal and not all DI engined cars do this, quite a few early R56s have, Keano's has done it twice (luckily under warranty for both).

Pretty sure you or someone else already mentioned other car companies have found solutions to this.
Would you like to share with me your personal experiences with other cars "not having the same adverse effects of carbon buildup"?
I would be really interested in this, since you've mentioned...
Just beware, my personal list is big...
 

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Werthers
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Would you like to share with me your personal experiences with other cars "not having the same adverse effects of carbon buildup"?
I would be really interested in this, since you've mentioned...
Just beware, my personal list is big...
My point was the earlier cars, hence BMW re-designing the N14 engine with revisions to reduce the carbon build up. Like many things, when you buy the first round of products from a company that have not been tested in the long term you always risk buying something that is not guaranteed to work properly in 3 years time. That is also why the price of early R56s in the UK are very cheap at the moment, they look attractive to people who don't understand about these issues, pretty sure the N18 engine will be better protected than my engine is to carbon build up, sure it wont be completely removed but it wont be as bad as mine. With time, research and development these problems can and will be resolved but to simply generalise and throw all DI engines into one bag of fail is simply not true.
 

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Themis
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Discussion Starter #364
My point was the earlier cars, hence BMW re-designing the N14 engine with revisions to reduce the carbon build up. Like many things, when you buy the first round of products from a company that have not been tested in the long term you always risk buying something that is not guaranteed to work properly in 3 years time. That is also why the price of early R56s in the UK are very cheap at the moment, they look attractive to people who don't understand about these issues, pretty sure the N18 engine will be better protected than my engine is to carbon build up, sure it wont be completely removed but it wont be as bad as mine. With time, research and development these problems can and will be resolved but to simply generalise and throw all DI engines into one bag of fail is simply not true.
George you are talking generally here and I am talking specifically...there is a huge difference between us...
You want to talk specifically about the small changes they made over the years trying to resolve the underlying problem of carbon build up? I would be more than happy to get into this technical discussion.

Don't misunderstand me, whatever I share here, either I have seen it with my own eyes, or I have owned it. That's how much specific I like to be...
 

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Werthers
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6,596 Posts
George you are talking generally here and I am talking specifically...there is a huge difference between us...
You want to talk specifically about the small changes they made over the years trying to resolve the underlying problem of carbon build up? I would be more than happy to get into this technical discussion.

Don't misunderstand me, whatever I share here, either I have seen it with my own eyes, or I have owned it. That's how much specific I like to be...
I just picked up on the comment:

All DI engines have the same adverse effects of carbon buildup.
Only stating that things are slowly getting better but yes for people like us with the original poor design we have pretty much no choice but to either sell the car or work towards a solution, sadly this solution comes at a cost and a cost that many regular users cannot afford. I guess we are lucky to have members like you on board :)
 

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Well here is what I did. And this is pretty old.

So after reading through all the posts about catch cans and our PVC system I decided this is the easiest thing to do.

First I contacted our good pal from the other side of the pond CZAR and purchased to of the caps from him. I received them in the mail today and got right on installing them.

First I removed to hose from the crankcase to the manifold and put in the two caps.



Then I went to the local auto parts store and picked up a neoprene plug and a breather filter (to substitute till I can get an appropriate length hose to run under the car)

This is the end result.



I have a longer hose now so all the crankcase gasses are come out of the front port and away into the air under the car. Not in my motor at all. If any of you are worried that this may cause positive pressure in your valve cover or crank case it wont. This is why,

So after all this talk about the PCV system I decided to go grab my valve cover and do a little investigating. Thanks to CZAR for cutting apart one of his valve covers and taking a bunch of pictures (which I tactfully acquired), I can give an even more detailed explanation of what is going on.

Ok so first we have the underside of the valve cover. As you can see in the picture below there are two ways for air to enter/exit the valve cover. The orange circle is a one way valve that will only let air into the valve cover. The white rectangle is an open port that will let air in or out. Mainly this is for air extraction. The white is just a paper towel I stuffed in the port so it would be more visible in the picture.


This is a picture of the extraction area of the PCV system


A view of the extraction port from the top side of the valve cover.


Open and closed flaps on the intake side of the PCV system.



Some pictures of this baffle thing.





Open and closed flaps on the manifold side of the PCV system.



Now that you have seen all the components, I will try to explain how this whole thing works. I sacrificed my lungs and braincells for this, so enjoy.

1. Either the rear or front PCV port can use vacuum to extract air from the valve cover. However neither port can force air into the valve cover.

2.When you block off one port the other is still able to extract air from the valve cover. The front port is more free flowing then the rear.

3.Blocking off the rear port will not cause pressure to build in the valve cover. The pressure will be able to escape from front port.

4.The orange one way valve is slightly confusing. It can only circulate air from the extraction port not air from outside. I think it is used as a way for oil to condense and drain back into the head. That way only fumes escape.

That pretty much sums it up. This should put all of the "PCV system" threads to rest. Questions? Ask away.

Additionally an explanation from CZAR

Firstly let me explain a little about the PCV, PCV is an acronym for Positive crankcase ventilation, inside the cam cover there are a few entrapment passages and direction chambers, which do their best to separate the suspended oil particles from the passing vapour, this vapour is then vacuum drawn from the cam cover passageways through a valve flap, the first direction is through the rear PCV line into the intake manifold, next, when the vacuum draw from the turbo (building boost pressure) is greater than the vacuum draw of the induction stroke from the pistons, the rear PCV valve flap is closed, as is the diaphragm in the cam cover, this then changes the direction flow of the vapour, and the vapour is vacuum drawn through the passenger side PCV valve flap into the air intake flow pre-turbo, once off boost and steady throttle is resumed then the vapour is once again vacuum drawn through the rear PCV line.

Now the actual valve flaps themselves are merely free falling self closing rubber diaphragms, there is no spring or piston actuation on either valve flap, however there is a sprung chamber diaphragm, which opens/closes under the vacuum draw from both the inlet manifold and turbo vacuum draw, this dictates the flow direction, and in the later re-designed cam cover allows excess pressure to vent through the inbuilt pressure release sprung valve.

There you have it. No more carbon buildup.
 

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Themis
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1,791 Posts
Discussion Starter #368 (Edited)
Great info mate...thanks for sharing.
I hope Roger is not mad, cause you've used all of his pictures regarding the head cover anatomy...(hopefully he can chime in).
These photos are not new to me, been following Roger's feedback since day one, but also did my own anatomy on my first head cover (the one without the pressure relief valve) and understood how it's working.

However, since I see that you are also using the later design head cover (with the small relief valve) i want to ask some questions...have you seen the anatomy of that? Do you know if it's using the same design internally? Does it have free moving flaps inside each port like the previous design?
Sadly the answer to all of these questions is: NO.
So, you can't rely on the anatomy of the previous design head cover to build your solution incorporating a different design cover...I won't say what's inside the new cover yet...but there are not free moving flaps for sure...

Another argument that I have is the blocking of the top port (the one operated in vacuum = the more frequently working one) how do you relieve the crankcase gases when you've blocked that port? Remember the right port is opened in boost conditions...you really create a positive pressure inside the head cover and force the one and only working port to open and relieve excess pressure...so this port is "constantly" open and the transition of open to closed will drive your free moving flap mad...why didn't you remove it then?

What happens when you've altered the cylinder pressure via a tuned map? Is the one and only port sufficient venting to atmosphere the excess crankcase gases? If you put this combo in track, will it perform well?

And the last one is the open filter venting to atmosphere...potentially dripping large quantities of oil on the ground, or on the undertray, maybe the turbo or the DP :sad:...don't know where you've positioned it finally but the first picture you posted doesn't seem like a good spot.

Another thought of mine is: why vent crankcase gases from one port when you could potentially have two of them? 1<2...

Finally...is that an open air filter on your intake?

Have a goodnight everyone.
 

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I hope Roger is not mad, cause you've used all of his pictures regarding the head cover anatomy...(hopefully he can chime in). Roger (Czar) doesn't mind the use of his images, if it helps the community understand, and that any use of my images in forum posts are stated as such.

However, since I see that you are also using the later design head cover (with the small relief valve) i want to ask some questions...have you seen the anatomy of that? Do you know if it's using the same design internally? Does it have free moving flaps inside each port like the previous design?
Sadly the answer to all of these questions is: NO.
So, you can't rely on the anatomy of the previous design head cover to build your solution incorporating a different design cover...I won't say what's inside the new cover yet...but there are not free moving flaps for sure... In the revised cylinder head camshaft cover they are now cylindrical free opening/closing port valves, as apposed to the early flat oblong free falling (opening/closing) valve flaps, as seen in my images.

Another argument that I have is the blocking of the top port (the one operated in vacuum = the more frequently working one) how do you relieve the crankcase gases when you've blocked that port? Remember the right port is opened in boost conditions...you really create a positive pressure inside the head cover and force the one and only working port to open and relieve excess pressure...so this port is "constantly" open and the transition of open to closed will drive your free moving flap mad...why didn't you remove it then?

What happens when you've altered the cylinder pressure via a tuned map? Is the one and only port sufficient venting to atmosphere the excess crankcase gases? If you put this combo in track, will it perform well?

And the last one is the open filter venting to atmosphere...potentially dripping large quantities of oil on the ground, or on the undertray, maybe the turbo or the DP :sad:...don't know where you've positioned it finally but the first picture you posted doesn't seem like a good spot.

Another thought of mine is: why vent crankcase gases from one port when you could potentially have two of them? 1<2...

Finally...is that an open air filter on your intake?

Have a goodnight everyone.
.
 

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S13 Race developements
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366 Posts
greatthread themis. great work. invaluable info here. this info will be useful for the tuning mini community for many years. keep it up and good luck with your build.
did you hybrid your turbo?
 

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Great info mate...thanks for sharing.
I hope Roger is not mad, cause you've used all of his pictures regarding the head cover anatomy...(hopefully he can chime in).
These photos are not new to me, been following Roger's feedback since day one, but also did my own anatomy on my first head cover (the one without the pressure relief valve) and understood how it's working.

However, since I see that you are also using the later design head cover (with the small relief valve) i want to ask some questions...have you seen the anatomy of that? Do you know if it's using the same design internally? Does it have free moving flaps inside each port like the previous design?
Sadly the answer to all of these questions is: NO.
So, you can't rely on the anatomy of the previous design head cover to build your solution incorporating a different design cover...I won't say what's inside the new cover yet...but there are not free moving flaps for sure...

CZAR and I have the same valve cover. Well for what counts anyway. I visually saw the flaps; they are rectangular and free moving.

Another argument that I have is the blocking of the top port (the one operated in vacuum = the more frequently working one) how do you relieve the crankcase gases when you've blocked that port? Remember the right port is opened in boost conditions...you really create a positive pressure inside the head cover and force the one and only working port to open and relieve excess pressure...so this port is "constantly" open and the transition of open to closed will drive your free moving flap mad...why didn't you remove it then?

Both ports will operate under vacuum. The crankcase gasses would be relieved out of the front port. It opens under vacuum or internal pressure. It wasn't really possible to remove. I thought about that.

What happens when you've altered the cylinder pressure via a tuned map? Is the one and only port sufficient venting to atmosphere the excess crankcase gases? If you put this combo in track, will it perform well?

With my tune I never had an issue from positive pressure in my valve cover. The gasses would get go out the front port.

And the last one is the open filter venting to atmosphere...potentially dripping large quantities of oil on the ground, or on the undertray, maybe the turbo or the DP :sad:...don't know where you've positioned it finally but the first picture you posted doesn't seem like a good spot.

Large quantities is a bit of an over statement. I have a longer hose running to the bottom of the car just past the steering rack. Where, when driving will be a low pressure. As for that amount of oil/oil vapor, would you rather it drip on the ground or cake onto your intake valves and pistons?

Another thought of mine is: why vent crankcase gases from one port when you could potentially have two of them? 1<2...

You could use both ports if you wanted to. I stuck with one to create a single directional flow.

Finally...is that an open air filter on your intake?

Yes, yes it is. Intake temps being a few degrease above ambient really doesn't matter. Once you pressurize it force it through an intercooler and mix it with W/M it's pretty cool.

Have a goodnight everyone.
.
 

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Themis
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1,791 Posts
Discussion Starter #372
greatthread themis. great work. invaluable info here. this info will be useful for the tuning mini community for many years. keep it up and good luck with your build.
did you hybrid your turbo?
Thanks mate, I am trying to help (myself and others)...
No, I won't hybrid it just yet...the engine needs running in for starters.
Also, I have changed a fair bit of parts and I want the turbo to be the same in order to see the gains from other parts...
I want to compare with my previously tuned stage.
It looks like someone else is going that way sooner than me...
 

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Themis
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1,791 Posts
Discussion Starter #373
Tbh Roger (Czar) I am a little disappointed by you...I was hoping for a more derailed post than that...
It will probably take you 5 minutes to write a proper solution to this problem and share it with us...and even comment on other's thoughts...
 

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Themis
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1,791 Posts
Discussion Starter #374
Just a small clarification added:

The strangest thing of all is that my engine with the above fucked up by carbon internals, had smooth torque-power curves, never misfired, consumed logical amounts of oil, wasn't hesitant whatsoever, idled fine from cold, didn't loose it's breath in track after much abuse...
All of that in 44k miles! It was just some exhaust valves were starting to leak slightly, however the intake valves (which were full of carbon) sealed perfectly!

Weird stuff going on...
Anyway, crankcase gases redirection is the solution and it is a fairly simple task...head cover redesign might be needed.
 

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Werthers
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6,596 Posts
Just a small clarification added:

The strangest thing of all is that my engine with the above fucked up by carbon internals, had smooth torque-power curves, never misfired, consumed logical amounts of oil, wasn't hesitant whatsoever, idled fine from cold, didn't loose it's breath in track after much abuse...
All of that in 44k miles! It was just some exhaust valves were starting to leak slightly, however the intake valves (which were full of carbon) sealed perfectly!

Weird stuff going on...
Anyway, crankcase gases redirection is the solution and it is a fairly simple task...head cover redesign might be needed.
This is also what I find strange... My car has 52,000 miles on the clock and I am sure it's probably full of carbon but it does not seem to heaitate, never stutters and it is always producing the same numbers on the dyno with no erratic results.

I guess the only way to know what is really being potentially lost is a full strip down an clean and then dyno the car afterwards...

I just find it a bit strange how the car still appears to work "fine" yet at the same time it's probably full of carbon.
 

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do you know what is the working min and max oil pressure in this engine according to BMW spec?

(0,7bar min....3,0bar max) = stupid oil system indeed...

lets see what can be done...anyone volunteering to help?
Realoem shows a revised oil pump , with an extra solenoid? What happened there , what was cocked up to start with ?
 

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GP Pilot 1238
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So is the consensus that running a twin OCC is pointless when in reality you can just block three of these PCV points and just drain one to the bottom of the car (or even both as Thepenl thinks) ??

Or is running a twin OCC almost as good?
 

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Werthers
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I think we should create a new thread instead of filling this with other content and leave this space for Themis and his project. I will create a new thread for ideas and plans on how to tackle carbon build up.
 
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