Video Part 8 "The 3.8L Scoring Duo" is out
12-17-2019, 02:30 PM
#76
Pro
Really cool picture father and daughter project. When I lived in the southern USA very impressed by intelligence and creativity of kids and teens there. We're in western USA now and my 5-yr-old daughter is off the scale creative and competent, there's hope for the future.
12-17-2019, 04:24 PM
#77
The following users liked this post:
Doug H (12-18-2019)
12-17-2019, 04:30 PM
#78
Rennlist Member
Hmm, really makes me want to sell my 997 and get a second 928 as my daily. No doubt the 928 has its issues too, notably thrust bearing failure on the automatic transmission cars from 85 on, but that is very preventable. The 928 engine (clean sheet Porsche design BTW) is known to be just about bullet proof, and known to go for hundreds of thousands of miles if maintained properly. Whole different breed of car, and not "modern", but a great Porsche nevertheless. Maybe I should simply stop reading these threads
12-17-2019, 04:43 PM
#79
Burning Brakes
Hmm, really makes me want to sell my 997 and get a second 928 as my daily. No doubt the 928 has its issues too, notably thrust bearing failure on the automatic transmission cars from 85 on, but that is very preventable. The 928 engine (clean sheet Porsche design BTW) is known to be just about bullet proof, and known to go for hundreds of thousands of miles if maintained properly. Whole different breed of car, and not "modern", but a great Porsche nevertheless. Maybe I should simply stop reading these threads
12-17-2019, 04:44 PM
#80
Drifting
Seems to me after watching the bore scoring series that the biggest contributing variable in the equation is the materials composition of the bore. Since this is a common denominator among the M96 and M97 engines, wouldn't it be fair to say, that this is not about chance or luck, but about reality of what we've been given and in time, the engine will need to be rebuilt with nikasil plating that has proven itself in the Mezger engines?
Certainly many people will be able to use their car for a long productive run. Hell, my buddy beats the crap out of his 997, redlines it from start up, maybe changes his oil every 15-20,000 kms and only maintains it when something brakes and his car has no signs of scoring. Me, who drove my car according to all common wisdom, changed the oil every 5000kms, had scoring at less than 80k (45k miles). Luck of the draw it seems
12-17-2019, 04:46 PM
#81
Drifting
12-17-2019, 04:47 PM
#82
Three Wheelin'
This isn't Ava's first rodeo.. At age 8 she has already built engines, knows the 4 strokes of a 4 stroke engine, and loves this stuff.
It took her 30 minutes to swap these pistons, and pins to achieve the tightest balance possible, then we removed minimal material to zero out the delta between all 6 pistons.
12-17-2019, 06:34 PM
#83
Former Vendor
Teaching her things is about the only thing I care about now. She has her own engine program, but not with Porsche engines. You'll see some of it in the future.
12-18-2019, 12:02 AM
#84
Nordschleife Master
Join Date: Mar 2003
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Yes but being that definitive will drive certain people on here crazy.
Certainly many people will be able to use their car for a long productive run. Hell, my buddy beats the crap out of his 997, redlines it from start up, maybe changes his oil every 15-20,000 kms and only maintains it when something brakes and his car has no signs of scoring. Me, who drove my car according to all common wisdom, changed the oil every 5000kms, had scoring at less than 80k (45k miles). Luck of the draw it seems
Certainly many people will be able to use their car for a long productive run. Hell, my buddy beats the crap out of his 997, redlines it from start up, maybe changes his oil every 15-20,000 kms and only maintains it when something brakes and his car has no signs of scoring. Me, who drove my car according to all common wisdom, changed the oil every 5000kms, had scoring at less than 80k (45k miles). Luck of the draw it seems
12-18-2019, 12:06 AM
#85
Nordschleife Master
Join Date: Mar 2003
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Seems to me after watching the bore scoring series that the biggest contributing variable in the equation is the materials composition of the bore. Since this is a common denominator among the M96 and M97 engines, wouldn't it be fair to say, that this is not about chance or luck, but about reality of what we've been given and in time, the engine will need to be rebuilt with nikasil plating that has proven itself in the Mezger engines?
12-18-2019, 12:20 AM
#86
Nordschleife Master
Join Date: Mar 2003
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I'll share something with you. I don't even like Porsche cars anymore. What drives me is figuring things out, and developing fixes. The crap I deal with from comments on these forums makes me feel like a jerk when I drive my own Porsche's that I worked my *** off to buy over the years. Today, the cars I dreamed about owning, I have. When I get in those cars, I crank them up, and I feel like a jerk. The only exception is my old 912E, and that is probably because the car is shunned by Porsche owners, and it has a VW engine installed from the factory, and because I have owned the car for 24 years. I owned that car back when I had to take out trash at a local strip mall to afford to buy food. I hauled trash in a 1962 VW bus with no back window, and the charging system didn't work. Some nights if I forgot to charge the battery earlier in thee day, I'd have to drive home without any headlights, else the coil didn't have enough energy to provide spark to keep the engine running. It is lonely at the top, but it sure was a bitch, at the bottom.
Today I drove the 912E to pick my daughter up from school, and on the way I decided to sell every other Porsche that I own. I then realized that I cannot even sell the damn cars without having to worry about some jackass buying them that can't be pleased.
12-18-2019, 02:11 AM
#87
Nordschleife Master
I'll share something with you. I don't even like Porsche cars anymore. What drives me is figuring things out, and developing fixes. The crap I deal with from comments on these forums makes me feel like a jerk when I drive my own Porsche's that I worked my *** off to buy over the years. Today, the cars I dreamed about owning, I have. When I get in those cars, I crank them up, and I feel like a jerk. The only exception is my old 912E, and that is probably because the car is shunned by Porsche owners, and it has a VW engine installed from the factory, and because I have owned the car for 24 years. I owned that car back when I had to take out trash at a local strip mall to afford to buy food. I hauled trash in a 1962 VW bus with no back window, and the charging system didn't work. Some nights if I forgot to charge the battery earlier in thee day, I'd have to drive home without any headlights, else the coil didn't have enough energy to provide spark to keep the engine running. It is lonely at the top, but it sure was a bitch, at the bottom.
Today I drove the 912E to pick my daughter up from school, and on the way I decided to sell every other Porsche that I own. I then realized that I cannot even sell the damn cars without having to worry about some jackass buying them that can't be pleased.
Today I drove the 912E to pick my daughter up from school, and on the way I decided to sell every other Porsche that I own. I then realized that I cannot even sell the damn cars without having to worry about some jackass buying them that can't be pleased.
As for selling them, there I couldn't agree more. Had my near flawless GTS on the market a while ago. High end after market wheels, OEM GT2 seats and a replaced rear bumper that's not even showing up on Carfax. Yet going by the offers and accompanied comments you'd think I was selling something that belonged on a wholesale auction site. Took it off the market and will keep it until it's ready to be scrapped. Best decision I ever made in terms of selling a car.
12-18-2019, 05:11 AM
#88
I think it is great that there are (at least) two well-established specialists sharing their knowledge on this forum and taking the time to respond to questions asked.
Of course they have a financial interest, but if you have the necessary expertise and solutions why would that be a bad thing?
They are not forcing anyone who feels that the messages are all about fear-mongering to have an engine rebuild.
I do agree however that the tone of Jake Raby's posts is sometimes overly dramatic and showing a bit of a Calimero-complex.
That probably doesn't help in getting the message across. Nevertheless, he is without doubt an expert in his domain and I enjoyed watching the video's that were made available.
Of course they have a financial interest, but if you have the necessary expertise and solutions why would that be a bad thing?
They are not forcing anyone who feels that the messages are all about fear-mongering to have an engine rebuild.
I do agree however that the tone of Jake Raby's posts is sometimes overly dramatic and showing a bit of a Calimero-complex.
That probably doesn't help in getting the message across. Nevertheless, he is without doubt an expert in his domain and I enjoyed watching the video's that were made available.
12-18-2019, 08:11 AM
#89
996.2/Nutty Professor, yes Porsche and most manufacturers knew all about silicon deposition but planned to use hard coated pistons with it that were proven to work with Alusil (944/968). The Lokasil material is a source of the problem because Alusil forms silicon particles when the mixture is over saturated and they are therefore very evenly distributed and naturally bonded in the matrix. Lokasil does not create such even dispersion or bonding quality (in our opinion). But the hard-coated original pistons could stand the gradually released particles and the increased clearances brought about through bores migrating oval helped increase the clearance space - no bore scoring problems in the first range of engines up to the last 996 3.4's - nothing to criticise Porsche for in those f irst engines regarding bore scoring.
The problem of bore scoring emerged when clearances were kept closer (by changing the silicon particle mix and size to reduce creeping ovality and increase hoop stress resistance) and the particle size of Lokasil 2 was increased while at the same time the piston coating was forced to be changed to something softer. Those that have seen the final piston coating picture in our report (showing the coating bubbled away from the aluminium piston face underneath but still in tact) will be able to work out two important logical conclusions, (1) that the bonding was poor and (2) that the first piece of Lokasil grit that gets trapped between the bore and that patch will tear it away from the piston leaving uncoated aluminium to try and resist the impact of the next particle release which every expert agrees it cannot do!
Going back to Alusil with the Gen 2 9A1 meant that it could survive with a piston coating better than plastic coatings in Lokasil but made by a different process to the original hard coated pistons and the change to a closed deck block was also made possible as the casting didn't need to be designed to withstand high pressure casting and therefore could be constructed with sand cores.
The new piston coating (Ferrotec) we find not as hard or durable as the old coatings but seems to be perfect for the Gen 2 engines until something else causes a seizure when it deteriorates more quickly and dramatically as a result.
So - yes - you are right about the bore material but the piston coating has an equal influence because they work OK while the coating is in-tact and in place. It is only when the gradual release of gritty particles wears it away, or plucks poorly bonded parts away and exposes the bare aluminium piston face to the next particle loss - that scoring starts. Hence failure becomes more time and original quality based with some driving performance differences clouding the issue.
So yes - it wouldn't happen if particles were not released from the bore material (but it was always accepted that that was why all hypereutectic cylinders needed hard coated pistons). KS stopped supply of hard coated pistons when the manufacturing process was outlawed on H & S grounds in Europe and you can imagine the problem that created for Porsche - invested in a range of engines that KS believed needed hard coated pistons and no such product available any more? The plastic coated pistons were the best compromise they could find to maintain production but not as good as the original specifications.
As for driving styles - I have mentioned many times that it is high torque that impacts more than high revs because all bore scoring (or as it is more often described - "scuffing") is a well known and researched phenomenon that is at lower revs and higher torque, because it takes longer for the piston to rise and fall in the bore at lower revs and there is more time for the thrust forces to squeeze out the oil film - reducing its thickness. The inertia of the piston is also lower at low revs so the combination of the two enables the piston face to run harder and closer to the cylinder wall and that increases the grinding effect of the lose silicon particles into the piston coating.
At high revs the splash oil that was deposited on the bore by TDC has less time to be squeezed out (by improved hydrodynamic forces as piston speeds increase) and maintains a thicker oil film while the increased inertia of the piston reduces its impact on the bore.
As a result when we race these engines although they have our replaced cylinders we also fitted one with top support rings but retained the Lokasil bores and proved that at racing speeds the pistons do last longer (although rebuilds are usually needed after 1 to 2K racing anyway).
This ironically means that driving it like you stole it will extend the life of the bore to piston faces more than high throttle openings at lower revs. This also explains why we get a higher proportion of tiptronics failing sooner on average than manuals - because most often drivers pull away in second and with high torque. We proved that most tiptronic drivers spend more time at higher torque and lower revs than manual drivers who change up at a higher rev point and obviously use first gear to pull away. I guess that in the UK we have a higher proportion of manuals cars to tiptronics than in the USA? so this observation might not have been as easy to spot over there?
All the above (and much more) we have explained in our various posts, our reports and on our web-site in various forms for many years - but still the same questions appear - which is why we tried to encourage owners to read our full report (however long and difficult that may prove to be compared to admittedly much easer to watch and well produced videos) since it helps explain our version of the situation without requiring me to regurgitate the same stuff again and again while others continually confuse the situation by repeating irrelevancies we have disproved.
You are going to hate me for saying this but it does bring to mind Plato or Aristotle in 300 BC trying to persuade everyone that the earth was not flat but round when it took until 1500 AD for Magellan to prove them right by sailing round it, or Aristarchus promoting the theory that the Earth goes round the Sun (around 300 BC) when it took 18 centuries (until 1532 AD) for Capernicus to create a predictive model to prove it).
Go ahead an accuse me now of arrogance but gradually – and in time – you will find that what you may have previously believed about the whole subject of bore scoring is probably wrong and that what our research proved was right (or at least closer to the truth).
All this makes little difference to the provisions for fixing failed engines – some are good – some are not – some are different but OK – the customers make their choices.
We do not provide this information to try and change anyone’s mind about who is best to got to for repairs or what solution to approve – it is just that when we see advice that our research has shown to be wrong we feel it is our duty to inform the public what we think and let them decide which of conflicting explanations to believe and what to do about it.
It is unfortunate that this is interpreted as commercial rivalry as we have no reason to indulge in anything like that at all (and have great respect for the work some of our competitors do (including Jake and Charles @ LN) – we just simply have a perfect right to explain what we think causes various issues, make our findings available to the public and if others disagree with us they also have a perfect right to present their alternatives and we are happy for the public to make their own minds what to do next.
We neither seek to discredit anyone else trying to help owners with these very unfortunate problems nor take work from them – but doing nothing about answers to questions raised on the Internet when we see explanations that we believe to be wrong or misleading would not be in the publics interests and we feel we have a responsibility in these circumstances to make our genuinely held beliefs available for consideration – that’s all!
As you can see – my plan that my reports would cut down on the amount of time needed to respond to each individual question – has already failed miserably – please consider reading a copy before asking more questions for which the answers have already been provided in great detail in that report.
In response to the “Calimero complex” accusation may I respond by admitting that when we “experts” respond we take huge risks with public trolls and other fake experts trying to pull us down, people who are simply confused and standing their corner and ignorance that wants us to spend hours proving things to them for free plus those generally totally fed up that their Porsche has really let them down and want to take it out on anyone remotely involved open to public. Added to that are competitors doing a less reliable job but desperately wanting to get more work and discredit those who appear to be strong in the market.
I have every sympathy with Jake because he puts it out there and opens himself to criticism (and often wonder why I bother as well) – but we are in possession of the results of time and expertise spent delving into these subjects and I keep trying to maintain a calm frame of mind and continue to help people when they can be so difficult and depressing to deal with.
Charles, Jake and I have discussed trying to form a technology exchange partnership before but found too many obstacles in our path – due largely to being so far apart and from different cultural backgrounds – but I have no desire to do anything else other than convey what we know when questions are asked and try not to create conflict between us when the results differ – they are brilliant at what they do and the USA is lucky to have them available – but like all experts we naturally have our differences!
We thought that presenting what we found out in a report subject to a NDA would minimise any unnecessary public conflict (as it would not be on a public forum) and it would be good if others declined to try and fuel problems between us and just accepted our differences and made up their own minds about the best outcome for them.
Baz
The problem of bore scoring emerged when clearances were kept closer (by changing the silicon particle mix and size to reduce creeping ovality and increase hoop stress resistance) and the particle size of Lokasil 2 was increased while at the same time the piston coating was forced to be changed to something softer. Those that have seen the final piston coating picture in our report (showing the coating bubbled away from the aluminium piston face underneath but still in tact) will be able to work out two important logical conclusions, (1) that the bonding was poor and (2) that the first piece of Lokasil grit that gets trapped between the bore and that patch will tear it away from the piston leaving uncoated aluminium to try and resist the impact of the next particle release which every expert agrees it cannot do!
Going back to Alusil with the Gen 2 9A1 meant that it could survive with a piston coating better than plastic coatings in Lokasil but made by a different process to the original hard coated pistons and the change to a closed deck block was also made possible as the casting didn't need to be designed to withstand high pressure casting and therefore could be constructed with sand cores.
The new piston coating (Ferrotec) we find not as hard or durable as the old coatings but seems to be perfect for the Gen 2 engines until something else causes a seizure when it deteriorates more quickly and dramatically as a result.
So - yes - you are right about the bore material but the piston coating has an equal influence because they work OK while the coating is in-tact and in place. It is only when the gradual release of gritty particles wears it away, or plucks poorly bonded parts away and exposes the bare aluminium piston face to the next particle loss - that scoring starts. Hence failure becomes more time and original quality based with some driving performance differences clouding the issue.
So yes - it wouldn't happen if particles were not released from the bore material (but it was always accepted that that was why all hypereutectic cylinders needed hard coated pistons). KS stopped supply of hard coated pistons when the manufacturing process was outlawed on H & S grounds in Europe and you can imagine the problem that created for Porsche - invested in a range of engines that KS believed needed hard coated pistons and no such product available any more? The plastic coated pistons were the best compromise they could find to maintain production but not as good as the original specifications.
As for driving styles - I have mentioned many times that it is high torque that impacts more than high revs because all bore scoring (or as it is more often described - "scuffing") is a well known and researched phenomenon that is at lower revs and higher torque, because it takes longer for the piston to rise and fall in the bore at lower revs and there is more time for the thrust forces to squeeze out the oil film - reducing its thickness. The inertia of the piston is also lower at low revs so the combination of the two enables the piston face to run harder and closer to the cylinder wall and that increases the grinding effect of the lose silicon particles into the piston coating.
At high revs the splash oil that was deposited on the bore by TDC has less time to be squeezed out (by improved hydrodynamic forces as piston speeds increase) and maintains a thicker oil film while the increased inertia of the piston reduces its impact on the bore.
As a result when we race these engines although they have our replaced cylinders we also fitted one with top support rings but retained the Lokasil bores and proved that at racing speeds the pistons do last longer (although rebuilds are usually needed after 1 to 2K racing anyway).
This ironically means that driving it like you stole it will extend the life of the bore to piston faces more than high throttle openings at lower revs. This also explains why we get a higher proportion of tiptronics failing sooner on average than manuals - because most often drivers pull away in second and with high torque. We proved that most tiptronic drivers spend more time at higher torque and lower revs than manual drivers who change up at a higher rev point and obviously use first gear to pull away. I guess that in the UK we have a higher proportion of manuals cars to tiptronics than in the USA? so this observation might not have been as easy to spot over there?
All the above (and much more) we have explained in our various posts, our reports and on our web-site in various forms for many years - but still the same questions appear - which is why we tried to encourage owners to read our full report (however long and difficult that may prove to be compared to admittedly much easer to watch and well produced videos) since it helps explain our version of the situation without requiring me to regurgitate the same stuff again and again while others continually confuse the situation by repeating irrelevancies we have disproved.
You are going to hate me for saying this but it does bring to mind Plato or Aristotle in 300 BC trying to persuade everyone that the earth was not flat but round when it took until 1500 AD for Magellan to prove them right by sailing round it, or Aristarchus promoting the theory that the Earth goes round the Sun (around 300 BC) when it took 18 centuries (until 1532 AD) for Capernicus to create a predictive model to prove it).
Go ahead an accuse me now of arrogance but gradually – and in time – you will find that what you may have previously believed about the whole subject of bore scoring is probably wrong and that what our research proved was right (or at least closer to the truth).
All this makes little difference to the provisions for fixing failed engines – some are good – some are not – some are different but OK – the customers make their choices.
We do not provide this information to try and change anyone’s mind about who is best to got to for repairs or what solution to approve – it is just that when we see advice that our research has shown to be wrong we feel it is our duty to inform the public what we think and let them decide which of conflicting explanations to believe and what to do about it.
It is unfortunate that this is interpreted as commercial rivalry as we have no reason to indulge in anything like that at all (and have great respect for the work some of our competitors do (including Jake and Charles @ LN) – we just simply have a perfect right to explain what we think causes various issues, make our findings available to the public and if others disagree with us they also have a perfect right to present their alternatives and we are happy for the public to make their own minds what to do next.
We neither seek to discredit anyone else trying to help owners with these very unfortunate problems nor take work from them – but doing nothing about answers to questions raised on the Internet when we see explanations that we believe to be wrong or misleading would not be in the publics interests and we feel we have a responsibility in these circumstances to make our genuinely held beliefs available for consideration – that’s all!
As you can see – my plan that my reports would cut down on the amount of time needed to respond to each individual question – has already failed miserably – please consider reading a copy before asking more questions for which the answers have already been provided in great detail in that report.
In response to the “Calimero complex” accusation may I respond by admitting that when we “experts” respond we take huge risks with public trolls and other fake experts trying to pull us down, people who are simply confused and standing their corner and ignorance that wants us to spend hours proving things to them for free plus those generally totally fed up that their Porsche has really let them down and want to take it out on anyone remotely involved open to public. Added to that are competitors doing a less reliable job but desperately wanting to get more work and discredit those who appear to be strong in the market.
I have every sympathy with Jake because he puts it out there and opens himself to criticism (and often wonder why I bother as well) – but we are in possession of the results of time and expertise spent delving into these subjects and I keep trying to maintain a calm frame of mind and continue to help people when they can be so difficult and depressing to deal with.
Charles, Jake and I have discussed trying to form a technology exchange partnership before but found too many obstacles in our path – due largely to being so far apart and from different cultural backgrounds – but I have no desire to do anything else other than convey what we know when questions are asked and try not to create conflict between us when the results differ – they are brilliant at what they do and the USA is lucky to have them available – but like all experts we naturally have our differences!
We thought that presenting what we found out in a report subject to a NDA would minimise any unnecessary public conflict (as it would not be on a public forum) and it would be good if others declined to try and fuel problems between us and just accepted our differences and made up their own minds about the best outcome for them.
Baz
The following users liked this post:
pro1200 (12-18-2019)
12-18-2019, 10:31 AM
#90
[...]
In response to the “Calimero complex” accusation may I respond by admitting that when we “experts” respond we take huge risks with public trolls and other fake experts trying to pull us down, people who are simply confused and standing their corner and ignorance that wants us to spend hours proving things to them for free plus those generally totally fed up that their Porsche has really let them down and want to take it out on anyone remotely involved open to public. [...]
In response to the “Calimero complex” accusation may I respond by admitting that when we “experts” respond we take huge risks with public trolls and other fake experts trying to pull us down, people who are simply confused and standing their corner and ignorance that wants us to spend hours proving things to them for free plus those generally totally fed up that their Porsche has really let them down and want to take it out on anyone remotely involved open to public. [...]
But if I read statements such as "I solve problems technically, and don't have much respect for anything that goes on in a Court room", and "I worry about my task at hand, and don't give a damn about a bunch of guys sitting around in polyester suits arguing about crap", I find that unnecessary. Respect works both ways, and those kind of blunt, populist rants detract from the technical knowledge that is - quite obviously - present.
(by the way: guess my profession -
)