CALLING ALL DS3 OWNERS WITH THE THP ENGINE !!!....Who's had new engines ??

[cyclone]

In GDI engines no, as there is no fuel present to wash the backs of the inlet valves, and so we need and want as much of the oil particles to fall out of suspension as possible, that said in regular port injection it's not as critical, due to the fuel wash effect. That's my point any oil that makes it passed the separator and into the external PVC line is going to hit those valves whether it is suspended or not again there is no other place for it to go. So why let it fall out of suspension.
It doesn't matter whether the oil particles are in suspension or heavy settled liquid, even distribution will take place, as you have the same vacuum pull and sequence from all cylinders. Negative, that liquid film will not I repeat not travel evenly, in the perfect theoretical world yes but real world no it does not. Remember back to carbureted and TBI wet manifold systems and the even distribution problems that went along with them. Only now it's oil instead of fuel.
This cylinder head wasn't so much of a redesign to combat the carbon issue, it was simply a logical progression when you introduce dual vanos and inlet valve lift control. Maybe maybe not would have to be there to know but from all this you may have been. Were you? Come on you can tell us.

[Czar]

In GDI engines no, as there is no fuel present to wash the backs of the inlet valves, and so we need and want as much of the oil particles to fall out of suspension as possible, that said in regular port injection it's not as critical, due to the fuel wash effect. That's my point any oil that makes it passed the separator and into the external PVC line is going to hit those valves whether it is suspended or not again there is no other place for it to go. So why let it fall out of suspension. Because the longer it stays out of suspension the better, and coagulation will start to take place, this coagulation of the liquid oil is further aided from debris particle collection which escapes the air filtration process, and any already formed soft coagulated particles from within the engine itself.
It doesn't matter whether the oil particles are in suspension or heavy settled liquid, even distribution will take place, as you have the same vacuum pull and sequence from all cylinders. Negative, that liquid film will not I repeat not travel evenly, in the perfect theoretical world yes but real world no it does not. Remember back to carbureted and TBI wet manifold systems and the even distribution problems that went along with them. Only now it's oil instead of fuel. I remember all too well, however you can't associate offset unguided open plenum NA fuelling, with centrally guided forced induction dry air pressure feeds, with a central location even distribution will be better managed, than any offset, as was back in the good old days, you refer to.
This cylinder head wasn't so much of a redesign to combat the carbon issue, it was simply a logical progression when you introduce dual vanos and inlet valve lift control. Maybe maybe not would have to be there to know but from all this you may have been. Were you? Come on you can tell us.

Lets just say, I have lots of involvement on various platforms.

[Gazza]

So does all this mean that the PCV is not the cause of the engine stuttering? If not, then what is? Mine has 2,500 miles and is getting worse every day!!!

[Czar]

So does all this mean that the PCV is not the cause of the engine stuttering? If not, then what is? Mine has 2,500 miles and is getting worse every day!!!

Whoa stop, this is taking many directions now, PCV is an acronym for positive crankcase ventilation, inside the 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, 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 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 as for your engine stutter, there are many symptoms to this, insufficient fuel pressure, ignition issues, timing issues, temperature sensor failures, pressure load/convertor sensors, etc etc etc, that said, when excess carbon is built up on the inlet valves, and this takes many thousands of miles, this can lead to throttle hesitation.

[cyclone]

yah carbs kind of miss them "not really". Actually I like the rough analogy especially when the engineers have implemented the same solutions "the port injection of the PVC gas i.e. RCZ". Wonder if the future holds a way to directly inject the blow by and bypass the valves altogether?

And that coagulation business sounds scary in my intake track. You talking about the same kind of sludge that can build with a blown head gasket?

Ha I think this conversation would be better over a pint.

[Czar]

yah carbs kind of miss them "not really". Actually I like the rough analogy especially when the engineers have implemented the same solutions "the port injection of the PVC gas i.e. RCZ". Wonder if the future holds a way to directly inject the blow by and bypass the valves altogether?

And that coagulation business sounds scary in my intake track. You talking about the same kind of sludge that can build with a blown head gasket?

Ha I think this conversation would be better over a pint.

Carburettors were and are fantastic if, you had a single venturi for each individual cylinder, like ITB's, as for crankcase gaseous vapour bypassing the inlet valves, currently there is no other solution other than further development of oil/air separation within the cam cover/cylinder head entrapment passages, if your talking about emulsified oil/water mix, the creamy sludge, then no, the coagulation of oil will always happen, however it is nothing to worry about in your intake tract, whilst there are oil particles present in the air flow, there will always be an amount of liquid oil in the lowest points of the air intake tract, and over time, through many engine/air heat cycles, a small amount of coagulation will take place.

[Ragnarok]

Looks like this thread is for me. I have a Racing which was diagnosed to have a broken piston nro. 2. According to service, a large part had disintegrated from the piston.
15k miles on it.

[pmatil]

Ugh sounds bad. Any hope on getting at least part of it under warranty?

[Ragnarok]

Ugh sounds bad. Any hope on getting at least part of it under warranty?

Factory warranty is still valid so it should (better) go under that.