I note that this is an old thread from a time before I had joined the forum,and I have to admit to being a bit of a Porsche enthusiast for many years thus given I am up for any excuse to avoid the weeding task that is next on the "to do" list, I am more than happy to share my Porsche thinking lest this topic heading be beamed up by someone looking to buy a second third fourth hand or more Porsche 911..
From the outset I admit to never having put a spanner to a mid 80`s on Porsche, thus my opinion may be worth nothing, though I have restored in varying degrees 60`s to 80`s air cooled 911`s having owned a few, even did a bit on a friends 928 which was a very impressive machine in it`s day, but as madmax noted, it seems those who may hold more fundamentalist ideals can create enough of a fuss to restrict, change and perhaps even determine market values of potentially "iconic" sports cars in time...? The 928 was a high tec beast compared with the 911s of the time, it is old hat by today`s standards, I think the main complaints were that it was to big to be a true sports car and not..err.. air cooled.... though note that today`s 911`s are much the same size and perhaps weight as the 928, not to mention the obvious..
I ever thought Porsche to be no more than souped up VW`s at a time when Lotus was for me the ultimate in auto-motion... In time I owned and restored a few Lotus cars and became aware of some of the ..err..less than ideal aspects of their design, which did not advantage those trying to keep them on the road as they aged, given so many may had endured a rather hard life .. I fell into Porsche ownership as the result of circumstance at a time when I had moved on from the possible fragility of sports cars and had looked towards GT ownership.... Nah, not the usual GT`s of the era, but the real deal, perhaps an AM V8 or similar, I ended up with a pair of Interceptors, 6286cc of American muscle in a rather stylish body..... I had flirted with a CV8 some years previously and remembered well the ROAR of that big V8 which was a tad different from the souped up Mini`s I ran at the time..
Sorry for the thread drift, but then I do tend to ramble on somewhat...
Back to Porsche, I swapped my interceptor during the UK fuel Crisis of the 70`s and having by that time been educated to some degree that perhaps there was something to Porsche other than a souped up VW, I found a sixties 912 in much need of repair with no MOT and no chance of getting one without major work, the owner happy to do a deal.... Only then did I really begin to learn about what an old air cooled Porsche was really like to own.. Nuts and bolts that I would expect to be seized and break as soon as I put a spanner to them would unscrew, my appreciation of superior engineering design and construction grew right down to the feel of the switchgear, however this was one rusted out old car so much the same as all the Brit iron, it had it`s weaknesses... In time I came to own another couple of 911 SC Porsches both of which had broken valve springs when I bought them... I put that down to the mix of the old Bosch rotor arm with built in rev limiter that seized over time and that like any performance engine in the hands of those expecting the time to change up the box was determined by the engine beginning to run out of steam as the revs rose, which of course does not happen in an engine designed for REAL performance..prepared to rev up the range until something breaks..!!! Fortunately air cooled Porsches have dual valve springs an inner and an outer, the outer brakes leaving the weaker inner to perform solo.. I gained experience on refitting valve springs without removing the head..
I ran air cooled Porsche cars for circa 10 years, before returning to m/cycling to enjoy the roads hereabouts, then one day I found myself following a Vintage Bentley down the side of Loch Tay, which caused me to consider a possible alternative to cold knees.. On returning home I jumped on the then new to me internet and found the MSCC DG, and amongst those present was a prominent Canadian Morganeer who convinced me that my thinking on acquiring a +8 was definitely the way to go... the rest they say is history..
However in recent times I began to think to return to Porsche ownership as I had an ever stiffening knee and getting in and out of my Morgan was becoming difficult thus a replacement may need to be considered, and logically enough a 911 took pole position..
I spent quite a bit of time researching 911s and still had a few Porsche friends with whom I chatted, though the interweb is full of information and working one`s way through it and the disinformation can take time...fortunately time enough for my leg to miraculously un-stiffen it`s self..
I had thought to buy a modern Porsche though the more I read of the water cooled 911 issues, the less keen I became.... Sure, it may only be between 1-3% of water-cooled Porsches that may have engine issues, and of course the folk who turn up on the web are perhaps likely to be those looking to air a grievance, justified or otherwise.... BUT, I suspect the chance of suffering something untoward that may be VERY expensive to resolve may put folk off, more so when it seems Porsche created something that looks like a perhaps needed insurance scheme for their cars against engine failure as well as other parts of the car, but it seems the engine issues were perhaps attracting attention in time..? It seems that if the IMS goes even at car park speeds the engine can become unrepairable given the possible level of internal destruction....For me that kinda reduced my ardour for other than an air cooled Porsche...?
One other aspect of the Porsche market is that it seems to have attracted rather a lot of "rough trade" with all sorts of tricks and traps to catch the unwary to separate customers from their hard earned while they are wearing those rose tinted glasses and rather vulnerable having a head full of hype perpetuated by the motoring press keen to keep themselves in a job.... hmm..?
So buying a Porsche may be potentially be more of a minefield than many other sports cars.....?
I have read recently of someone who had as a kid set his sights on buying a 911 2.4s and in recent times paid out circa £235k for a 911 described as exactly such, from a supposed specialist Porsche dealer... and later found out that the car was perhaps best described as a bitsa...
Scary stuff indeed. Lots of time and legal stuff later he received a refund, the car is seemingly still out there..?? Yup when the market decides something is rare, collectable or in some way special, it is perhaps best to buy from a REAL specialist...?
There are "stories" of goings on even within the official dealership, with a Porsche experience day car being sold through the dealership network without informing the customer that the car has been used as one might expect on a Porsche experience day...? Again in time an alternative deal was seemingly worked out after the buyer found out the cars background... Hmm...?
My own thinking is that the build quality of the early air cooled cars may not be there in the water cooled cars in some areas , thinking of simple stuff like breaking exhaust manifold to head studs, that corrode considerably requiring the heads to be drilled to fit replacement fixings and such like stuff right up to the last of the 997s and perhaps beyond... but if you want real engineering insight to the possible issues try beaming up this URL created by an engineer who REALLY knows his stuff when it comes to 911s, it is a bit long but an interesting insight none the less...?
https://www.hartech.org/images/downloads/Hartech%20Porsche%20Buyers%20Guide.pdfAs for a non original Porsche dealership where you might have some confidence, these guys apparently have a good name.
http://www.911virgin.com/porsche/buyingtips/I have no connection with either..
That`s about it, other than to say perhaps my Morgan may in time be accompanied or replaced with/by a 3.2 Carrera as the Porsche of choice, or perhaps a 964 or 993 if I have to ..I do like to see the tops of the wings from the drivers seat, and listen to the wale in the tail, though perhaps not quite a substitute for the long bonnet of my Morgan and it`s V8 rumble at this present time...
You know it makes sense! 
