Another Porsche Boxster engine failure..
Discussion
Maybe this has been covered before (I've been reading this thread in fits and starts in between less intellectually-demanding activities
)... Might the apparent prevalence of issues with 996 and Boxster engines not be as much due to the larger production volumes of these cars as to some inherent design flaw in the engines themselves?
As I understand it (note: no research here, so feel free to curse me for a lackwit dilettante), after Wiedeking took over and chainsawed the factory-floor stock shelves, etc., Porsche started producing many more cars than had been the case before. New production techniques meant that costs could be trimmed, and prevailing economic conditions and brand awareness put Porsche in the perfect place to serve an increasing demand for their cars with an increasing output from their newly-efficient factories.
My point is this: even if the rate of severe failures was halved (from, say, 1% in 993s to 0.5% in 996s - again, note these are made-up numbers) this could easily be masked by the factory producing over double the number of 996s. In actual fact (as I understand it) 996 volumes are over 10 times greater than 993 volumes, so could this be the main driver in the apparent rise in failure rates rather than some hitherto hidden basic incompetence on Porsche's part?
As an aside, I rather suspect that the 996 is doomed to be another 964 - fundamentally unloved in a market which (probably irrationally) prefers its predecessor and successor. But nevertheless, a cracking ownership proposition.
As for the OP, well... Buy the ticket, take the ride. I got a warranty on my 928, because in a year that involved buying the car, I knew I couldn't fund a new engine. Next year I probably won't, but I shan't blame Porsche if it goes "bang".
)... Might the apparent prevalence of issues with 996 and Boxster engines not be as much due to the larger production volumes of these cars as to some inherent design flaw in the engines themselves?As I understand it (note: no research here, so feel free to curse me for a lackwit dilettante), after Wiedeking took over and chainsawed the factory-floor stock shelves, etc., Porsche started producing many more cars than had been the case before. New production techniques meant that costs could be trimmed, and prevailing economic conditions and brand awareness put Porsche in the perfect place to serve an increasing demand for their cars with an increasing output from their newly-efficient factories.
My point is this: even if the rate of severe failures was halved (from, say, 1% in 993s to 0.5% in 996s - again, note these are made-up numbers) this could easily be masked by the factory producing over double the number of 996s. In actual fact (as I understand it) 996 volumes are over 10 times greater than 993 volumes, so could this be the main driver in the apparent rise in failure rates rather than some hitherto hidden basic incompetence on Porsche's part?
As an aside, I rather suspect that the 996 is doomed to be another 964 - fundamentally unloved in a market which (probably irrationally) prefers its predecessor and successor. But nevertheless, a cracking ownership proposition.
As for the OP, well... Buy the ticket, take the ride. I got a warranty on my 928, because in a year that involved buying the car, I knew I couldn't fund a new engine. Next year I probably won't, but I shan't blame Porsche if it goes "bang".
I've often considered consolidating my company E92 and my lairy weekend car for a 911 so have found this to be a fascinating discussion!
If I did so then I'd follow the same logic as always - you either a) buy the best warranty you can, or b) stash a greater amount of money away to fix it if it breaks and then blow it on upgrades or a big holiday if it doesn't.
My own car is older and simpler so I choose option b whereas my brother for example, is more risk averse and actually swapped his BMW trade-up plans across to an Audi S4 when they doubled their M-Car warranty costs. That Porsche even agree cover cars to such a high mileage and that this costs *half* that of a comparative warranty on an M3 seems to demonstrate incredible product confidence to me.
The bottom line is that expensive cars are expensive to run - even if they're cheap.
df
If I did so then I'd follow the same logic as always - you either a) buy the best warranty you can, or b) stash a greater amount of money away to fix it if it breaks and then blow it on upgrades or a big holiday if it doesn't.
My own car is older and simpler so I choose option b whereas my brother for example, is more risk averse and actually swapped his BMW trade-up plans across to an Audi S4 when they doubled their M-Car warranty costs. That Porsche even agree cover cars to such a high mileage and that this costs *half* that of a comparative warranty on an M3 seems to demonstrate incredible product confidence to me.
The bottom line is that expensive cars are expensive to run - even if they're cheap.
df
Quaint said:
Maybe this has been covered before (I've been reading this thread in fits and starts in between less intellectually-demanding activities )... Might the apparent prevalence of issues with 996 and Boxster engines not be as much due to the larger production volumes of these cars as to some inherent design flaw in the engines themselves?
Yes, this has been covered before, in fact this thread covers it well too - only one engine design exhibits the RMS, cylinder wall and intermediate shaft failures to a noticeable extent, other engines have generally random and far less serious issues (although personally RMS is a small issue). )... Might the apparent prevalence of issues with 996 and Boxster engines not be as much due to the larger production volumes of these cars as to some inherent design flaw in the engines themselves?Fundamentally (in my own view) I think the cylinders are not strong enough and that the intermediate shaft design is not robust enough. In addition the RMS is caused IMO by the double crank-case design (Frame + cover) being too weak/misaligned.
In fact Ford had a 'similar' problem when the bean counters changed the cast ali crank case to save 50p to a flattened case and a steel bolted sump. All is fine as long as you never ever loosened those sump bolts, at which point the case twisted and the engine was scrap.
Can anyone confirm the 2008 911 moves away from the M96/M97 open-deck double-shell crank case engine design?
It has been reported that the new engine has a one piece crankcase and no intermediate shaft and also that it has thicker cylinder walls - but I cannot confirm this yet.
The reduction of hands on engineering experience of younger designers compared to older ones like me (who had to fix our bicycles our motorbikes and our 1st car engines ourselves or not drive at all) can often be seen in modern designs. Frequently we can forsee a problem before it is even showing itself and are usdually right. It is not the fault of modern designers - they are simply generally (and of course there are exceptions) less practical and more education based and have less opportunity to find out at a practical level what works and what does not. I would welcome comment from any other engine builders or engineers on this subject as I am sure they too have seem the consequnces of a wealthier society and the lack of hands on experience of the younger generation - on basic engineering abilities.
So almost any tradditional engineer that saw the cam chain design on the 944 S, S2 and 968 that would imediately say - it will be a weak spot (which it turned out to be).
Similarly the Boxster and 996 engines and gearboxes have what I would call a few weird ideas that I (and others) would have questioned if we were involved at the design stage and probably altered - and these include the cylinder wall thickness, intermediate shaft bearing shields (and gearbox bearing shields) and intermediate shaft spindle size, the cut outs just where you don't want then in the cylinder head gaskets, the RMS not being located in line (or fitted ino a seperate cover that could be aligned afterwards or an extension to the crank carrier), the double tapered tensioner spindle, using the cam cover to lock down the camshafts, the assembly method for the pistons etc, the very narrow con rod and main bearing shells (when there is space for them to be wider), etc etc.
I was similarly amazed when I realised that the reason for the 996 cylinder walls being thinner than the Boxster range was basically because they used the same casting as the Boxster S but with bigger cylinder bores (rather than investing in a different core tool). I would have thought that the quantities and extra power being developed would have made the provision of a new core tool essential.
Please don't accuse this of being a big headed comment just saying "I know better" or "arn't I clever" because these items would honestly be looked at with concern by any experienced (and probably older) engine - engineer - and at least questioned (and probably revised). They are not rocket science and very basic and obvious.
What does surprise me though is that - if lots of people can so quickly identify these problem areas (even before they are proven to be a problem) then why were they in the original design - and more importantly why was nothing done to cure the problems more quickly (as the spares supply and warranty claims must have made Porsche aware of them a long time ago) or is this due to the politics within big engineering businesses getting in the way? (or fear of admission resulting in expensive and harmful publicity).
I am often confused when I see things like this and always at first assume it is because they know something I don't and that they will be proven right but then - more often than not - the reverse happens. I don't always get it right first time though as I also 1st thought that the RMS issue was all caused by misalignment of the crankshaft and reported this on here years ago (after testing a few with a clock guage) - but since then I also think the fact that there are 2 chains pumping oil at up to 45mph directly onto the seal (unlike most engine designs) at the rear crank end) contributes to its weakness. In view of this it is surprising that the new seal for the 997 (that can be retrofitted to other earlier models) - while being able to accomodate slight misalignment has discarded the lip spring - becoming another of these "mysteries of engineering decision making" that have held back this engine for years.
In comparison I always marvel at the cleverness and simplicity of the engine designs of the original 911 and 944 (with the Lancaster balance shafts) and I guess while they were developed over many years, Porsche had to bring out something new and water cooled that was better than that long development route achieved - which would always be very hard 1st time.
Sometimes similar businesses employ people of a similar age that move up and on for many years (handicapping the development of younger subordinates) and then all retire more or less together - leaving a void (similar can happen in football teams) and there is a need to rebuild from another generation who inevitably don't have the same experience (and the introduction of Japanese engineering to cut production costs must have caused many dissagreements in house I am sure). Todays students are every bit as clever (perhaps more so) and with proper guidance can become absolutely brilliant - but they need to bang their fingers with a hammer a few times in the process.
I hadn't thought of the increased sales numbers for the Boxster and 996 influencing failure quantities (very clever of that man) because even 993's, 944's and early 911's had some isolated failures - and perhaps the numbers refelct little worse in the end results anyway? What were the actual numbers - anyone got a clue?
All in all I still think a few problems with such a new design were inevitable, the cars are great, the engine problems minimal and manageable and used cars prices have fallen to reflect the situation (as they do) resulting in them being good buys (if some protection can be managed for a major failure). It is just a shame Porsche didn't reflect their role in selling cars with these inherent weaknesses by simply reducing/subsidising the prices of parts neccessary to repair them, providing short blocks or subsidising replacement engine prices (which they clearly could have so easily afforded).
Baz
The reduction of hands on engineering experience of younger designers compared to older ones like me (who had to fix our bicycles our motorbikes and our 1st car engines ourselves or not drive at all) can often be seen in modern designs. Frequently we can forsee a problem before it is even showing itself and are usdually right. It is not the fault of modern designers - they are simply generally (and of course there are exceptions) less practical and more education based and have less opportunity to find out at a practical level what works and what does not. I would welcome comment from any other engine builders or engineers on this subject as I am sure they too have seem the consequnces of a wealthier society and the lack of hands on experience of the younger generation - on basic engineering abilities.
So almost any tradditional engineer that saw the cam chain design on the 944 S, S2 and 968 that would imediately say - it will be a weak spot (which it turned out to be).
Similarly the Boxster and 996 engines and gearboxes have what I would call a few weird ideas that I (and others) would have questioned if we were involved at the design stage and probably altered - and these include the cylinder wall thickness, intermediate shaft bearing shields (and gearbox bearing shields) and intermediate shaft spindle size, the cut outs just where you don't want then in the cylinder head gaskets, the RMS not being located in line (or fitted ino a seperate cover that could be aligned afterwards or an extension to the crank carrier), the double tapered tensioner spindle, using the cam cover to lock down the camshafts, the assembly method for the pistons etc, the very narrow con rod and main bearing shells (when there is space for them to be wider), etc etc.
I was similarly amazed when I realised that the reason for the 996 cylinder walls being thinner than the Boxster range was basically because they used the same casting as the Boxster S but with bigger cylinder bores (rather than investing in a different core tool). I would have thought that the quantities and extra power being developed would have made the provision of a new core tool essential.
Please don't accuse this of being a big headed comment just saying "I know better" or "arn't I clever" because these items would honestly be looked at with concern by any experienced (and probably older) engine - engineer - and at least questioned (and probably revised). They are not rocket science and very basic and obvious.
What does surprise me though is that - if lots of people can so quickly identify these problem areas (even before they are proven to be a problem) then why were they in the original design - and more importantly why was nothing done to cure the problems more quickly (as the spares supply and warranty claims must have made Porsche aware of them a long time ago) or is this due to the politics within big engineering businesses getting in the way? (or fear of admission resulting in expensive and harmful publicity).
I am often confused when I see things like this and always at first assume it is because they know something I don't and that they will be proven right but then - more often than not - the reverse happens. I don't always get it right first time though as I also 1st thought that the RMS issue was all caused by misalignment of the crankshaft and reported this on here years ago (after testing a few with a clock guage) - but since then I also think the fact that there are 2 chains pumping oil at up to 45mph directly onto the seal (unlike most engine designs) at the rear crank end) contributes to its weakness. In view of this it is surprising that the new seal for the 997 (that can be retrofitted to other earlier models) - while being able to accomodate slight misalignment has discarded the lip spring - becoming another of these "mysteries of engineering decision making" that have held back this engine for years.
In comparison I always marvel at the cleverness and simplicity of the engine designs of the original 911 and 944 (with the Lancaster balance shafts) and I guess while they were developed over many years, Porsche had to bring out something new and water cooled that was better than that long development route achieved - which would always be very hard 1st time.
Sometimes similar businesses employ people of a similar age that move up and on for many years (handicapping the development of younger subordinates) and then all retire more or less together - leaving a void (similar can happen in football teams) and there is a need to rebuild from another generation who inevitably don't have the same experience (and the introduction of Japanese engineering to cut production costs must have caused many dissagreements in house I am sure). Todays students are every bit as clever (perhaps more so) and with proper guidance can become absolutely brilliant - but they need to bang their fingers with a hammer a few times in the process.
I hadn't thought of the increased sales numbers for the Boxster and 996 influencing failure quantities (very clever of that man) because even 993's, 944's and early 911's had some isolated failures - and perhaps the numbers refelct little worse in the end results anyway? What were the actual numbers - anyone got a clue?
All in all I still think a few problems with such a new design were inevitable, the cars are great, the engine problems minimal and manageable and used cars prices have fallen to reflect the situation (as they do) resulting in them being good buys (if some protection can be managed for a major failure). It is just a shame Porsche didn't reflect their role in selling cars with these inherent weaknesses by simply reducing/subsidising the prices of parts neccessary to repair them, providing short blocks or subsidising replacement engine prices (which they clearly could have so easily afforded).
Baz
hartech said:
Lots of stuff asking why things aren't perfect when they get designed.
I've spent the last twentysomething years designing electronic and electromechanical things so although not engine related, all designs end up not going quite as they should do some of the time.There's plenty of reasons why but whenever something in the way of a new technology is introduced then the risk level is increased. In an ideal situation before designing something you know what the production capability is. Take a simple turned part, to be made on a lathe. If you've made plenty of similar parts in the past then you've got statistical data available showing how capable the process is, you'll know what tolerances the new part will have in reality. If its a new process then you'll have some idea but the theory won't always tell the full story.
There's a choice here, either build a production spec machine at a lot of expense and run it as it would be used in production in order to get the data you really need to use in the design or you make some assumptions. It's rare due to cost that this solution is used so assumptions are made that aren't always as good as they should be. Sometimes there are calculated gambles, lets remove some weight from these parts as it reduces material and hence cheaper, lighter means better in a sports car but the computer analysis says it will be ok, the couple of test pieces work ok but as no company will put together a full production machine just to test a process at the start of the design then when the production line starts to run in earnest some problems are encountered. Sometimes this is spotted very early on and a good solution is found to improve things to an acceptable level. The worse incidence on one of my designs was only noticed when we'd already got 15000 units in the field and the line had been running for two years. I've had other designs that have been fine at prototype stage and when first run down a production line just don't work. If it can go wrong then it will on a production line. Materials are used that aren't to spec, parts end up out of tolerance and decisions are made whether to scrap lots of expensive parts or use them in the belief of some rough calculations. Ideally you'd spend longer on the decision but the cost of a stopped production line is very high.
So lets take something a little more realistic. Something simple like a metal tube that needs to be kept within certain size limits, needs a certain amount of strength both axially and radially and needs good surface hardness. It also needs to be dimensionally very accurate and there's cost and weight limits in place too, everyone wants good value.
There's plenty of ways of getting to the end result, use a hard material that's turned to size, is expensive, slow to produce as you can't turn hard materials as quickly as soft ones, the harder material is more expensive and heavier.
So a cheaper, lighter, weaker material is used, quick and easy to machine and then a surface hardening is used. The longer the hardening process is run for then deeper the hardening. More expensive, takes longer on the line so fewer units can be produced. Ideally you'd set the hardness thickness sufficient that the part won't wear out but just how thick should that be? in an engine scenario, is that 100,000 miles, 200k, 500k? what about the possibility that there won't be oil there occasionally, it happens, engines are started cold, some more than others, on a cylinder liner the cylinder won't be perfectly round, the piston also won't be perfectly round. The temperatures that the engine is operated at will change the size of the parts as they expand with heat and some compromises and decisions will get made that are sometimes regretted several years later.
Ideally you'd design a car that nothing broke on until it got to a known mileage and then everything would cease and you'd dispose of scrap pile. Real life doesn't work like that, some parts will wear out long before the designers had envisaged, some will carry on forever, there's a of cars out there with 300k+ miles on them, there's plenty more that have had something gone wrong much much earlier.
None of what I've written so far covered the personalities involved, people wishing their initial ideas would work and make it into the final design, the interactions between the management who want the design budget to be minimized, the marketing people that want to spend more on the launch than was spent on the design, the production engineer that hasn't quite grasped a minor but important issue and ends up weakening a part during the manufacturing process.
Modern cars are very very complex, the manufacturing process are complex and its inevitable that in the thousands of compromises that are decided on in a design some will not be ideal. Designs evolve and these compromises can be improved over time but each time a design takes a revolutionary step then we come back to the start. In electronics, the manufacturers had just got to grips making valves when the transistor arrived. They'd just got to grips with making transistors when the IC arrived. As long as progress is being made and new ideas are introduced then we'll continue to reap the benefits of new technology but we'll also suffer the consequences of things not always going as they should.
Now, anyone got a hangover cure?
I remember reading 'Honest John' in the Telegraph a while back. He was saying the Boxster engines could be fragile. Went about as far as he could without going as far as never buy one.
It's a shame, the Boxster is a great car but this problem does need to be resolved and I think Porka will lose credibility if they do not increase the warranty to 3 years. As somebody said in a previous post you even get 3 years from Ferrari and Lambo nowdays.
It's a shame, the Boxster is a great car but this problem does need to be resolved and I think Porka will lose credibility if they do not increase the warranty to 3 years. As somebody said in a previous post you even get 3 years from Ferrari and Lambo nowdays.
bad company said:
I remember reading 'Honest John' in the Telegraph a while back. He was saying the Boxster engines could be fragile. Went about as far as he could without going as far as never buy one.
I believe he had one which went pop. Hence he's got a vested interest in the subject of M96 reliability. I am also an engineer, though not yet worked in the automotive industry. Typically large companies will often do strange things. Smaller companies unsurprisingly tend to be more agile, hence why in this country we dominate F1, because F1 demands a small(ish) band of elite engineers working to mad backs against the wall deadlines, something us Brits are very good at.
The 16v 944/968 cam belt/chain design is a good example of a situation where it should have been done right, but the engineers involved where almost certainly told point blank to do it like this so it could be a simple bolt on to the 8v engine design. Personally I wish they hadn't bothered because the result is a mess and on the 968 with its LCA adjusting plunger an even bigger mess.
Sadly in my 10 years I have only had one time ever where I got the chance to do a clean sheet design but even then this was for a bid against a customer requirement that I didn't 100% agree with. Typically you are so constrained that really I would chance my arm and say, that almost none of the design flaws one sees from most well know manufacturers these days are the fault of the design engineers.
The 16v 944/968 cam belt/chain design is a good example of a situation where it should have been done right, but the engineers involved where almost certainly told point blank to do it like this so it could be a simple bolt on to the 8v engine design. Personally I wish they hadn't bothered because the result is a mess and on the 968 with its LCA adjusting plunger an even bigger mess.
Sadly in my 10 years I have only had one time ever where I got the chance to do a clean sheet design but even then this was for a bid against a customer requirement that I didn't 100% agree with. Typically you are so constrained that really I would chance my arm and say, that almost none of the design flaws one sees from most well know manufacturers these days are the fault of the design engineers.
I guess POLITICS eventually manages to f**k everything up - as I partly agree (NJH) that Commercial decisions often constrain design engineers and I can imagine pressure from the board not to manufacture another core for the Boxster 3.2 engine (for example) but just bore it out for the 996 - but commercial managers don't know what will and will not work well and if the "engineers" stood their ground enough - they would never have got the chance to try it (and it would ultimately have proven more profitable to change it and avoid the warranty replacements and loss of reputation).
Similarly - if the commercial managers wanted a cheap way to make the 968 a double OHC 16 valve design on top of the 944 engine - the engineers didn't have to come up with the small chain drive and if they hadn't the commercial people simply couldn't have done or even considered it as an option (as they are not design engineers) - so there is always some culpability on the engineers behalf. They could have come up with alternatives like a geared drive for example and an adjusting (sliding) cam belt tensioner that adjusted the timing.
Commercial people do make stupid decisions all the time. The best I ever had to endure was as Engine Development Director of Armstrong Equipment plc over 25 years ago and attending a board meeting to discuss (amongst other things) progress of the planned production of the next years moto cross machine. While well into production the governing body of the sport made a rule change on safety grounds to outlaw plastic fuel tanks and set a minimum front fork leg diameter - both of which would need replacing. The Chairman refused permission on the grounds that we had already presented a budget which he had approved and he couldn't sanction something that would result in a production loss. We on the other hand pointed out then that several hundred motorbikes would never have a market to sell into and remain unsold. Left with the choice of resigning or doing what he wanted (having done absolutely nothing wrong and with families to support) - after arguing hard - all present eventually reluctantly but meekly complied - finished the bikes - they didn't sell - the MD was eventually fired and they were eventually modified by which time they were a season out of date and had to be discounted etc. So I know only too well the stupidity of British Management decisions and the pressure they bring to bear - in fact it was the frustration of living within such impossible environments that led to me giving up my last employed job as general manager of a public limited aerospace company and returning to the relatively straightforward role of managing a small business with no outside interference, in a field I always loved - with my favourite car - a Porsche. A return to sanity and a huge amount of pleasure and satisfaction as well.
Perhaps a more likely scenario at Porsche would be that the older established engineers (who put quality in front of profitability) refusing to carry on with the new ideology and took early retirement - while a younger design team (frustratingly kept in th ebackground for too long by the old timers past success but promising the earth) came in to show how it could be done - only to get a few minor things wrong but then politically being unable or unwilling to admit it and get on with early design improvements/changes to fix a few expected minor weaknesses? Perhaps we will read an interesting book from those inside the establishment - one day entitled "The battle between Quality and Cost at Porsche)?
Those new engineers (or the Japanese consultants - if rumours are right) did a superb job by making a car even faster and better than its predecessor, a better drive, reduced emissions, while also reducing manufacturing costs by perhaps £5K to £10K/car and transforming Porsche from a lame duck sports car manufacturer to the most profitable in the World. The reliability resulting is little different to previous models - but it is just so frustrating that they couldn't have quickly changed a few minor details and supported owners more when trouble struck to minimise the consequences and return public perception of the marque where it always was - as it would have been so easy to do!
Baz
Similarly - if the commercial managers wanted a cheap way to make the 968 a double OHC 16 valve design on top of the 944 engine - the engineers didn't have to come up with the small chain drive and if they hadn't the commercial people simply couldn't have done or even considered it as an option (as they are not design engineers) - so there is always some culpability on the engineers behalf. They could have come up with alternatives like a geared drive for example and an adjusting (sliding) cam belt tensioner that adjusted the timing.
Commercial people do make stupid decisions all the time. The best I ever had to endure was as Engine Development Director of Armstrong Equipment plc over 25 years ago and attending a board meeting to discuss (amongst other things) progress of the planned production of the next years moto cross machine. While well into production the governing body of the sport made a rule change on safety grounds to outlaw plastic fuel tanks and set a minimum front fork leg diameter - both of which would need replacing. The Chairman refused permission on the grounds that we had already presented a budget which he had approved and he couldn't sanction something that would result in a production loss. We on the other hand pointed out then that several hundred motorbikes would never have a market to sell into and remain unsold. Left with the choice of resigning or doing what he wanted (having done absolutely nothing wrong and with families to support) - after arguing hard - all present eventually reluctantly but meekly complied - finished the bikes - they didn't sell - the MD was eventually fired and they were eventually modified by which time they were a season out of date and had to be discounted etc. So I know only too well the stupidity of British Management decisions and the pressure they bring to bear - in fact it was the frustration of living within such impossible environments that led to me giving up my last employed job as general manager of a public limited aerospace company and returning to the relatively straightforward role of managing a small business with no outside interference, in a field I always loved - with my favourite car - a Porsche. A return to sanity and a huge amount of pleasure and satisfaction as well.
Perhaps a more likely scenario at Porsche would be that the older established engineers (who put quality in front of profitability) refusing to carry on with the new ideology and took early retirement - while a younger design team (frustratingly kept in th ebackground for too long by the old timers past success but promising the earth) came in to show how it could be done - only to get a few minor things wrong but then politically being unable or unwilling to admit it and get on with early design improvements/changes to fix a few expected minor weaknesses? Perhaps we will read an interesting book from those inside the establishment - one day entitled "The battle between Quality and Cost at Porsche)?
Those new engineers (or the Japanese consultants - if rumours are right) did a superb job by making a car even faster and better than its predecessor, a better drive, reduced emissions, while also reducing manufacturing costs by perhaps £5K to £10K/car and transforming Porsche from a lame duck sports car manufacturer to the most profitable in the World. The reliability resulting is little different to previous models - but it is just so frustrating that they couldn't have quickly changed a few minor details and supported owners more when trouble struck to minimise the consequences and return public perception of the marque where it always was - as it would have been so easy to do!
Baz
hartech said:
I guess POLITICS eventually manages to f**k everything up - as I partly agree (NJH) that Commercial decisions often constrain design engineers and I can imagine pressure from the board not to manufacture another core for the Boxster 3.2 engine (for example) but just bore it out for the 996 - but commercial managers don't know what will and will not work well and if the "engineers" stood their ground enough - they would never have got the chance to try it (and it would ultimately have proven more profitable to change it and avoid the warranty replacements and loss of reputation).
Similarly - if the commercial managers wanted a cheap way to make the 968 a double OHC 16 valve design on top of the 944 engine - the engineers didn't have to come up with the small chain drive and if they hadn't the commercial people simply couldn't have done or even considered it as an option (as they are not design engineers) - so there is always some culpability on the engineers behalf. They could have come up with alternatives like a geared drive for example and an adjusting (sliding) cam belt tensioner that adjusted the timing.
Baz
I know it is OT in a way but with the 16v 4 pot motors personally I wouldn't have bothered. I reckon a 3 litre 8v with the pulse tuned inlet manifold like on the 968 and MAF instead of AFM would have been good for circa 200 Bhp (2.5 at 160 ish so not a massive jump to give something with 20% more displacement an extra 10 or so horses on top). The crazy thing is I can't see how the complexity they ended up with saved much money unless they where seriously worried about re-tooling etc, NRE/NRC and having to offset that against perhaps a short production run. For sure it is not the design one would propose as a long term change, what is most disapointing though is that it doesn't compare well with the massive power obtainable from the 4v head design used on the MB 190 cosworth engines. I heard once that Porsche had always intended for the 16v motor to be turbocharged. Even of this is true it makes no sense whatsoever on marketing grounds so makes it a somewhat difficult rumour to believe even if the source is reliable.Similarly - if the commercial managers wanted a cheap way to make the 968 a double OHC 16 valve design on top of the 944 engine - the engineers didn't have to come up with the small chain drive and if they hadn't the commercial people simply couldn't have done or even considered it as an option (as they are not design engineers) - so there is always some culpability on the engineers behalf. They could have come up with alternatives like a geared drive for example and an adjusting (sliding) cam belt tensioner that adjusted the timing.
Baz
Porsche had been running with low profits and minimal investment for years but I think they always intended a 3 litre turbo to be a 2 valve head because (a) it doesn't really need more valves as the forced charge still fills the engine and with such a large swept volume revs would always be limited, and (b) the 2.7 944 8 valve engine had a different block casting and a different mating head casting (but the same shape as the 3 litre S2 block and sharing the same head gasket) which enabled the 968S to be a 3 litre 8 valve turbo. It seems they would have only spent their precious limited investment funds on changing the 2.7 block and head if they had some other plan/reason - otherwise for just a short production run they could have left it as it was (as they only changed the stroke).
Baz
Baz
"and for those that think this is not a common problem and that its blown out of proportion by the internet - call any independant and they will fill you in. The garage that looked at mine claimed to have 4 996s and a couple of boxsters in that week with the failed engines, and that was no different than a normal week."
as someone thinking about buying their first porsche,I initially decided to do some research and found Pistonheads....last week i went to my local indi (very, very well known) and the proprieter himself tells me he has NEVER had a car back with catastrophic engine failure and if they are looked after properly they won't fail...so he's either telling fibs, or this is blown out of all proportion....
all leaves a really bad smell in the air.....S4 me thinks..
as someone thinking about buying their first porsche,I initially decided to do some research and found Pistonheads....last week i went to my local indi (very, very well known) and the proprieter himself tells me he has NEVER had a car back with catastrophic engine failure and if they are looked after properly they won't fail...so he's either telling fibs, or this is blown out of all proportion....
all leaves a really bad smell in the air.....S4 me thinks..
matthall said:
the proprieter himself tells me he has NEVER had a car back with catastrophic engine failure and if they are looked after properly they won't fail...so he's either telling fibs, or this is blown out of all proportion....
Well "if they are looked after properly they won't fail" is certainly and provably false by the number of 'properly looked after' cars failing.After all, the cylinder walls don't know if you had it serviced yesterday at an OPC, they just remember the compressions affecting the metal shape and strength until they give way.
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