Ian I do not come here to "debate" I leave that to the politicians....look where that gets us..!!! (-:
I come here to learn, and boy have I learned a lot...THANKS... Trying to remember any or all of it is the hard part.. Duh!
Seems obvious that the inefficiency of the AOS system is the issue with the DI engines...Quite where Porsche or anyone else might go with that who knows..?
Seems taking a step back might be the next step forward... if you get what I mean... ? (-:
IF the inlet tract and valves HAVE to be de-coked at circa 70k miles to overcome a considerable drop of in efficiency (?)... Forgive me but that does not seem to be...err...terribly efficient..?
The idea that spark plug threads are required to project into the combustion chamber for some reason seems to hint at cost cutting in the design process...?
So the exposed threads pick up carbon, which causes problems when trying to remove the spark plugs..?
How so, would seem to be the next question..? On trying to remove the plugs does the carbon jamb in the cylinder head threads risking damage to them as opposed to the harder material of the spark plug threads..?
Is the process for removal one of working the plugs back and forward to try to release the carbon from the exposed threads allowing the spark plug to be removed and the freed off carbon to end up where ..???
I guess my simplistic thought processes might lead me to add a couple of extra compression washers to the spark plug to ensure that the threads did not end up in the combustion chamber to collect carbon deposits...
Another rather obvious thought might be that perhaps Porsche engineers decided for that the best performance outcomes the PRECISE point at which the spark MUST be generated is in the present position in the combustion chamber...? IF that were the case, the exposed threads that seem to hold carbon so well, could be removed from the spark plug body and that area of the spark plug body smoothed off, similar to diesel pre-heat plugs..?
My thinking on the risks relative to the disruption to the engine ancillaries and bank balance involved in the de-coke process was more related to items that may be broken or damaged to get at the inlet tract, the stuck injector being one example, but it seems to me that water cooled Porsches have rather a lot of gubbins that requires to be disturbed, unbolted, unplugged and removed, compared to simpler designs of the past..Shrug..! Jeez even one electrical connection on a sensor disturbed, can cause issues, let alone a broken/corroded bolt or stud....?
All that aside... on using compression via a slow turn on the engine.... As you guys know I have never put hands on a water cooled 911, but I have used pressure to remove and replace valve springs on a Porsche engine to avoid removing the head, I think I explained the process some time back on this forum.. Combine that with an injector imitating a missile mentioned previously, and it seems possible that a bit of thinking out of the box might be worth a try...ONLY if the forces in play are WELL understood...
Compressed air can be used to start diesel engines the size of a house, so spitting out an injector seems a possibility, as to how that process might be controlled.... there may be ways and means worth trying...? (-:
Ian, if you are reading this, I am flattered, please take no time to reply to my innate ramblings.... I am as ever just thinking in type, in an attempt to keep my brain from seizing up..
ld: