Lokasil 1, 2 and Gen 2 9A1 engines
11-03-2017, 09:56 AM
#31
Burning Brakes
"The shrinkage we have measured in 9A1 engines is reality - the cause can be debated. It may be that what we have measured (a final piston clearance of say 0.0004" and 0.0006" in some cylinders) is the final complete distortion and will not get any worse - therefore as long as owners do not rag the engine from cold - they will never experience a seizure. Or they may continue to shrink until they all do - only time will tell."
Is this at the bottom of cylinder, everything at room temperature ? Assume thrust axis also.
Incredibly small....typical would be at least 2x these clearances, maybe more, depending on forge versus cast and amount of ovality ground into piston intentionally. Invar struts used to stabilize temp induced size changes of pistons ?
You say about as small a clearance as they get, as if more than this, seizure would result (no meaningful measurement then possible).
Have you ever measured a new engine in same directions, conditions, orientations, temperature ? I assume you have, since you are seeing aged engines with less clearances in this very critical area than new ones. I guess one could say all engine running clearances are critical though.
Looks like a 0W-40 oil is called for, as too thick at startup will hamper lubrication too long in warm up phase.
If I bought an 80K mile 9A1 car, I would (now after reading this) place a 100W bulb under the oil pan the night before I started the car in the morning, just to make the oil a little thinner at start up.
Help me on this.....if you raise the block temp to say 140 or so, along with the piston, does the clearance get higher or stay about the same (0.0004 inches).
Is this at the bottom of cylinder, everything at room temperature ? Assume thrust axis also.
Incredibly small....typical would be at least 2x these clearances, maybe more, depending on forge versus cast and amount of ovality ground into piston intentionally. Invar struts used to stabilize temp induced size changes of pistons ?
You say about as small a clearance as they get, as if more than this, seizure would result (no meaningful measurement then possible).
Have you ever measured a new engine in same directions, conditions, orientations, temperature ? I assume you have, since you are seeing aged engines with less clearances in this very critical area than new ones. I guess one could say all engine running clearances are critical though.
Looks like a 0W-40 oil is called for, as too thick at startup will hamper lubrication too long in warm up phase.
If I bought an 80K mile 9A1 car, I would (now after reading this) place a 100W bulb under the oil pan the night before I started the car in the morning, just to make the oil a little thinner at start up.
Help me on this.....if you raise the block temp to say 140 or so, along with the piston, does the clearance get higher or stay about the same (0.0004 inches).
Last edited by Ericson38; 11-03-2017 at 10:31 AM.
11-03-2017, 10:24 AM
#32
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11-03-2017, 12:47 PM
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11-03-2017, 01:33 PM
#34
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Bruce in Philly
11-03-2017, 01:35 PM
#35
11-03-2017, 02:30 PM
#36
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Baz, Thank you for the information. Do you know if the new 718 4 cylinder shares the same closed deck design as the 9A1. I assume it does. I wonder if it would heat cycle the same with less cylinder.
Jw
Jw
11-05-2017, 07:36 AM
#37
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Thread Starter
Although I try hard to exercise patience and tolerance in explaining technical issues when others with less knowledge, research time, and experience of stripping hundreds of examples over many years – post challenges – I am too busy right now to find the time to respond – sorry – please accept these brief answers for now.
Bruce in Philly – yes the 9A1 has proven of similar reliability to the older engines that Porsche developed its superb reputation for – the only reason for mentioning this potential fault is that if it is caused by stress releasing creep then it would only surface after a long period of reliability anyway (therefore making earlier reliability irrelevant) and especially because there is something that can be done to minimise or eliminate it – as long as owners warm up first.
Cosm3os, DC911s – you would be unlikely to spot anything imminent with M96/7 or 9A1 engines – the failures happen too quickly in seconds – but at least you can usually still use the M96/7 for several thousand miles before it really needs repairing – giving time to assess rebuild options.
JKW911 – your experience seems to support the above statement.
Doug H – yes YOU ARE WRONG! While I should not speak for Flat 6, our rebuilt engines are most certainly not less reliable than a new Porsche replacement (as hundreds of rebuilds over more than a decade and the resulting positive responses on the Internet support). If you put an engine with the same faults that instigated the failure back into the car – it should be equally reliable for a while but eventually likely to suffer the same faults. Note also “many manufacturers” (I cannot comment about Porsche) have different tolerances and rebuild specifications for after-market products and there have (for example) been a number of replacement bottom ends that have failed very early on in the UK. We replace the IMS with a proven solution and the cylinders with aerospace quality Nikasil replacements that are far superior, will run reliably with any piston coating (or without it) and convert the block to a closed deck design (so no distortion, seizing or scoring) – and all this for far less than the cost of a new replacement.
Bruce in Philly – I agree with some of your points (specifically about the financial problems at the time) but not all designs that are cheaper to produce need to be inferior and there are good aspects of the design as well. There were far more new ideas included together than Porsche were used to after decades of slow meticulous improvements of the original air cooled and 944/68 designs and a very small number simply didn’t prove as good.
The Bruce – All post 3.2 engines have thinner cylinders but the later engines (Cayman S, 3.6 and 3.8) do not go oval as quickly or crack as often as the early 3.4’s so the change to the stronger Lokasil type seems to coincide with this model run (but then the larger silicon particle size combined with the introduction of plastic coatings – combined to introduce mutual problems).
ASTR – thanks for your support – you are probably aware or our unique technical background, years of warning about potential problems that time proved right (typical of which was the advice to replace the cam chains on 944S, S2 and 968 engines by 70K to delay the need for new camshafts), unique manufacturing experience and facilities in house and of solving problems with reliable solutions.
Wayne Smith – You would hope that owners would know to warm up first but the ones we have failure experience of – did not – partially because either they found the cars to be bullet proof and got used to getting away with that treatment or because they simply didn’t care – but it is interesting that the nature of the creep we measured would catch them out eventually.
Ericson38 – I do hope you don’t think we are amateurs! – Of course we measured the cylinders all over – all 6 cylinders in 4 engines that had failed (all that had gone oval at the bottom in the thrust direction leaving the miniscule clearances). We also bought a low mileage engine from a crashed car that had not seized and found that similarly shrinking in the same direction with the same variance between different cylinders and to a size consistent with gradual creep (although not yet as far as the higher mileage ones that had failed). We have also bought a high mileage car still running OK to verify the symptoms. Good engineers can reliably diagnose cause from effect in relatively small numbers (made easier if not restrained by internal politics or potential claim consequences) and able to concentrate on solutions which in themselves are always easier when the evidence is obvious (something the original designers did not benefit from). In other words “it is easy to be clever after the event”. We could not manage a time warp back to 2009/10 (to measure a new unused engine) but the fact that the cylinders are oval (and you cannot machine an oval bore) implies that they have changed shape – and if that was not the case why would they not have failed sooner? Thinner oil may indeed help but is probably not necessary if the owners simply warm up the engines before getting the pistons too hot (so they don’t expand quicker than the cylinders) by which time a thicker oil will be thin.
Hackers-Pschorr – Late 2008.
JWYR I don’t yet know enough about the 718 4 but assume it may have moved on to plasma sprayed cylinder bore finishes – that should be superior to anything except Nikasil (but cheaper than Nikasil). This new process should become the natural solution once the production process is perfected and volumes make it viable – although the change to electric drive may well stifle development.
In Conclusion – while we accept that everyone has a right to an opinion and that we are not automatically right every time – it would help us continue to provide such well researched information for the benefit of owners – if responders would just stop and think for a short while about things before launching into questioning our posts or trying to devalue them by often irrelevant side issues posted by those with little or no experience of engineering and without the benefit of looking critically at hundreds of engines and finding out about their background from the owners. We have spent a lot of time and money checking this out, presently have 5 different cars under test for various projects and do so professionally.
We make it as clear as possible what is evidential and what is opinion. The evidence is that early M96 engines cracked bores and later M96/7 ones didn’t (despite greater loads) but scored. Researching from the manufacturer themselves revealed differences that are consistent with the outcome. 9A1 engines that we have measured have shrinking bores (FACT) they all failed after a considerable number of heat cycles (that promote aged stress relieving), have a large part of the casting adjacent that could explain it and seized in short journeys under fast use in very cold weather. Our resulting comments and advice might not be right but until proven otherwise it is surely better to take note and warm up the cars first and also better that we continue to research the problem and have decided to develop solutions – as we did for the previous model’s faults – that have since saved a lot of people a lot of money, restored their faith in the marque and minimised the harm such failures could do.
Baz
Bruce in Philly – yes the 9A1 has proven of similar reliability to the older engines that Porsche developed its superb reputation for – the only reason for mentioning this potential fault is that if it is caused by stress releasing creep then it would only surface after a long period of reliability anyway (therefore making earlier reliability irrelevant) and especially because there is something that can be done to minimise or eliminate it – as long as owners warm up first.
Cosm3os, DC911s – you would be unlikely to spot anything imminent with M96/7 or 9A1 engines – the failures happen too quickly in seconds – but at least you can usually still use the M96/7 for several thousand miles before it really needs repairing – giving time to assess rebuild options.
JKW911 – your experience seems to support the above statement.
Doug H – yes YOU ARE WRONG! While I should not speak for Flat 6, our rebuilt engines are most certainly not less reliable than a new Porsche replacement (as hundreds of rebuilds over more than a decade and the resulting positive responses on the Internet support). If you put an engine with the same faults that instigated the failure back into the car – it should be equally reliable for a while but eventually likely to suffer the same faults. Note also “many manufacturers” (I cannot comment about Porsche) have different tolerances and rebuild specifications for after-market products and there have (for example) been a number of replacement bottom ends that have failed very early on in the UK. We replace the IMS with a proven solution and the cylinders with aerospace quality Nikasil replacements that are far superior, will run reliably with any piston coating (or without it) and convert the block to a closed deck design (so no distortion, seizing or scoring) – and all this for far less than the cost of a new replacement.
Bruce in Philly – I agree with some of your points (specifically about the financial problems at the time) but not all designs that are cheaper to produce need to be inferior and there are good aspects of the design as well. There were far more new ideas included together than Porsche were used to after decades of slow meticulous improvements of the original air cooled and 944/68 designs and a very small number simply didn’t prove as good.
The Bruce – All post 3.2 engines have thinner cylinders but the later engines (Cayman S, 3.6 and 3.8) do not go oval as quickly or crack as often as the early 3.4’s so the change to the stronger Lokasil type seems to coincide with this model run (but then the larger silicon particle size combined with the introduction of plastic coatings – combined to introduce mutual problems).
ASTR – thanks for your support – you are probably aware or our unique technical background, years of warning about potential problems that time proved right (typical of which was the advice to replace the cam chains on 944S, S2 and 968 engines by 70K to delay the need for new camshafts), unique manufacturing experience and facilities in house and of solving problems with reliable solutions.
Wayne Smith – You would hope that owners would know to warm up first but the ones we have failure experience of – did not – partially because either they found the cars to be bullet proof and got used to getting away with that treatment or because they simply didn’t care – but it is interesting that the nature of the creep we measured would catch them out eventually.
Ericson38 – I do hope you don’t think we are amateurs! – Of course we measured the cylinders all over – all 6 cylinders in 4 engines that had failed (all that had gone oval at the bottom in the thrust direction leaving the miniscule clearances). We also bought a low mileage engine from a crashed car that had not seized and found that similarly shrinking in the same direction with the same variance between different cylinders and to a size consistent with gradual creep (although not yet as far as the higher mileage ones that had failed). We have also bought a high mileage car still running OK to verify the symptoms. Good engineers can reliably diagnose cause from effect in relatively small numbers (made easier if not restrained by internal politics or potential claim consequences) and able to concentrate on solutions which in themselves are always easier when the evidence is obvious (something the original designers did not benefit from). In other words “it is easy to be clever after the event”. We could not manage a time warp back to 2009/10 (to measure a new unused engine) but the fact that the cylinders are oval (and you cannot machine an oval bore) implies that they have changed shape – and if that was not the case why would they not have failed sooner? Thinner oil may indeed help but is probably not necessary if the owners simply warm up the engines before getting the pistons too hot (so they don’t expand quicker than the cylinders) by which time a thicker oil will be thin.
Hackers-Pschorr – Late 2008.
JWYR I don’t yet know enough about the 718 4 but assume it may have moved on to plasma sprayed cylinder bore finishes – that should be superior to anything except Nikasil (but cheaper than Nikasil). This new process should become the natural solution once the production process is perfected and volumes make it viable – although the change to electric drive may well stifle development.
In Conclusion – while we accept that everyone has a right to an opinion and that we are not automatically right every time – it would help us continue to provide such well researched information for the benefit of owners – if responders would just stop and think for a short while about things before launching into questioning our posts or trying to devalue them by often irrelevant side issues posted by those with little or no experience of engineering and without the benefit of looking critically at hundreds of engines and finding out about their background from the owners. We have spent a lot of time and money checking this out, presently have 5 different cars under test for various projects and do so professionally.
We make it as clear as possible what is evidential and what is opinion. The evidence is that early M96 engines cracked bores and later M96/7 ones didn’t (despite greater loads) but scored. Researching from the manufacturer themselves revealed differences that are consistent with the outcome. 9A1 engines that we have measured have shrinking bores (FACT) they all failed after a considerable number of heat cycles (that promote aged stress relieving), have a large part of the casting adjacent that could explain it and seized in short journeys under fast use in very cold weather. Our resulting comments and advice might not be right but until proven otherwise it is surely better to take note and warm up the cars first and also better that we continue to research the problem and have decided to develop solutions – as we did for the previous model’s faults – that have since saved a lot of people a lot of money, restored their faith in the marque and minimised the harm such failures could do.
Baz
11-05-2017, 09:49 AM
#38
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Baz:
If my engine grenaded out of warranty and I was forced to come out of pocket $25k, I would in all likelihood pick the route that provided a big boost in performance (i.e., you or Fat 6 rebuild to 4.0) as it takes some of the sting out of spending $25k on a used car versus paying $25k to return the car to its original condition.
You, however, are saying that the catastrophic failures are related to heat cycles over extended periods of time that perhaps cannot be easily replicated in bench testing by an OEM such as Porsche.
If true, how do you guys have the ability to perform such testing on your rebuilds to ensure your rebuilds won't be even more prone to similar long term catastrophic failure, especially when increasing the capacity and power of the previously used, failed engines. Simply saying none ever failed is cool and all, but I doubt you guys have anywhere near as many rebuilds out there as Porsche factory engines that have endured nearly as many heat cycles as the Porsche factory engine to develop an informed opinion of whether your rebuilds are more or less reliable long term than a new factory replacement.
Look, I totally get the option of going to a 4.0 and increasing performance when confronted with having to blow $25k after a catastrophic failure. I would likely go that route myself just to take some of the sting out, but not sure you guys have the data or bench testing to claim your rebuilds would be more reliable than a factory replacement engine over long term use.
If my engine grenaded out of warranty and I was forced to come out of pocket $25k, I would in all likelihood pick the route that provided a big boost in performance (i.e., you or Fat 6 rebuild to 4.0) as it takes some of the sting out of spending $25k on a used car versus paying $25k to return the car to its original condition.
You, however, are saying that the catastrophic failures are related to heat cycles over extended periods of time that perhaps cannot be easily replicated in bench testing by an OEM such as Porsche.
If true, how do you guys have the ability to perform such testing on your rebuilds to ensure your rebuilds won't be even more prone to similar long term catastrophic failure, especially when increasing the capacity and power of the previously used, failed engines. Simply saying none ever failed is cool and all, but I doubt you guys have anywhere near as many rebuilds out there as Porsche factory engines that have endured nearly as many heat cycles as the Porsche factory engine to develop an informed opinion of whether your rebuilds are more or less reliable long term than a new factory replacement.
Look, I totally get the option of going to a 4.0 and increasing performance when confronted with having to blow $25k after a catastrophic failure. I would likely go that route myself just to take some of the sting out, but not sure you guys have the data or bench testing to claim your rebuilds would be more reliable than a factory replacement engine over long term use.
11-05-2017, 09:49 AM
#39
Burning Brakes
Thanks for the reply. This is the first I ever heard of cylinder - piston clearances decreasing in a specific dimension with time and miles. But you found it.
Since overall the cylinder circumference in this lower area of the bore has to increase with miles and wear, the orthogonal clearance measurement (90 deg from the wrist pin axis) would be going up, and that I think would possibly increase blowby, if the ring pack's travel zone extends this far down.
Since overall the cylinder circumference in this lower area of the bore has to increase with miles and wear, the orthogonal clearance measurement (90 deg from the wrist pin axis) would be going up, and that I think would possibly increase blowby, if the ring pack's travel zone extends this far down.
11-05-2017, 11:29 AM
#40
Baz, Thank you for sharing !
I have 3 questions (which can be relevant to many RLs)
1. I have a 997.1 c2s 2005 TIP S.
The engine has been replaced by "Recall".
Anyway, today, I have a new M97 engine with upgraded IMS, "large" (original by PORSCHE).
Is there another difference in the engines?
Can I be calm?
2. Does the engine reliability affect the use of Tiptronic s than a manual transmission system?
3. Which engine oil do you recommend? Today I use Mobil 1 5W50.
Many thanks
I have 3 questions (which can be relevant to many RLs)
1. I have a 997.1 c2s 2005 TIP S.
The engine has been replaced by "Recall".
Anyway, today, I have a new M97 engine with upgraded IMS, "large" (original by PORSCHE).
Is there another difference in the engines?
Can I be calm?
2. Does the engine reliability affect the use of Tiptronic s than a manual transmission system?
3. Which engine oil do you recommend? Today I use Mobil 1 5W50.
Many thanks
11-05-2017, 01:42 PM
#41
Baz ... Thank you for initiating this discussion and continuing to share your experience.
As you know, these things will always create controversy. Part of science is filtering out banter and the red herrings. You are in a far better position to do that than any of us. Stay strong 8) And enjoy your (partial) retirement.
While we have your attention, I have heard from a very knowledgeable respected friend that the 9A1 possibly suffers from worn chain guides (Pete ... please correct me if I've got any of this wrong!!!). Based on your teardowns and other observations, do you feel these should be a part of a standard maintenance replacement program?
Please everyone ... this is only a question. I'm not wanting to create panic here, and this is not an attack on the 9A1 motor.
To define my car within a data table ... I daily drive my 2010 C4S PDK with 105K miles a minimum of 50 miles a day and have done more 600 plus miles in a day trips than I can count. The PDK easily allows me to keep the revs below 3000 until the oil temperature stabilizes. I live in a temperate climate (San Francisco Bay area) which is where the car grew up before me (it has been 3 years and 70K miles under my stewardship). Pre-knowledge of cold climate problems (and salt corrosion) made this history part of my shopping list. So extreme cold is not something the car has endured. I cannot account for how the car was treated during its first 35K miles, but I suspect it was with gentle hands. I have changed oil every 5K miles ... 7.5 US quarts out and the same back in each time. No additions between changes. Mobil 0W40. Oil level is maintained one full mark below full (2/3 on the indicator).
Back on topic ... My other commute option is my F250 pickup truck, which makes a lousy choice. In other words, taking the 997 out of service for a couple days is painful ... and I haven't done so to check my chain guides. I know the above is a lousy partial excuse for doing nothing, but I can't offer a data point here. Should I panic?!?!
This is the only other failure concern I have heard on the 9A1 motor. But you are smarter than I am.
Thanks in advance for any insights you can offer us as a group.
Wayne
As you know, these things will always create controversy. Part of science is filtering out banter and the red herrings. You are in a far better position to do that than any of us. Stay strong 8) And enjoy your (partial) retirement.
While we have your attention, I have heard from a very knowledgeable respected friend that the 9A1 possibly suffers from worn chain guides (Pete ... please correct me if I've got any of this wrong!!!). Based on your teardowns and other observations, do you feel these should be a part of a standard maintenance replacement program?
Please everyone ... this is only a question. I'm not wanting to create panic here, and this is not an attack on the 9A1 motor.
To define my car within a data table ... I daily drive my 2010 C4S PDK with 105K miles a minimum of 50 miles a day and have done more 600 plus miles in a day trips than I can count. The PDK easily allows me to keep the revs below 3000 until the oil temperature stabilizes. I live in a temperate climate (San Francisco Bay area) which is where the car grew up before me (it has been 3 years and 70K miles under my stewardship). Pre-knowledge of cold climate problems (and salt corrosion) made this history part of my shopping list. So extreme cold is not something the car has endured. I cannot account for how the car was treated during its first 35K miles, but I suspect it was with gentle hands. I have changed oil every 5K miles ... 7.5 US quarts out and the same back in each time. No additions between changes. Mobil 0W40. Oil level is maintained one full mark below full (2/3 on the indicator).
Back on topic ... My other commute option is my F250 pickup truck, which makes a lousy choice. In other words, taking the 997 out of service for a couple days is painful ... and I haven't done so to check my chain guides. I know the above is a lousy partial excuse for doing nothing, but I can't offer a data point here. Should I panic?!?!
This is the only other failure concern I have heard on the 9A1 motor. But you are smarter than I am.
Thanks in advance for any insights you can offer us as a group.
Wayne
11-05-2017, 01:56 PM
#42
User
Thread Starter
Doug H - we machine out the original cylinder and fit a new thick alloy cylinder (full wet liner) that is designed to accommodate any further shrinkage (which is unlikely as the engine will probably have just about finished I expect). By the way our rebuilds are usually around £8-£10K (for the whole car job) and significantly less for just engines.
f911 - Oil choice should be PK - avoid high torque pulling away in second (bore scoring worse at low revs and high torque) if driving fast use 1st.
Wayne - Not seen any evidence yet but early days.
Baz
f911 - Oil choice should be PK - avoid high torque pulling away in second (bore scoring worse at low revs and high torque) if driving fast use 1st.
Wayne - Not seen any evidence yet but early days.
Baz
11-06-2017, 01:06 PM
#45
Rennlist Member
Great thread Baz. Doesn't get any better than this, particularly for this forum.
You mentioned seeing more bearing failures with thicker oil. Any advice on oil test results? Bad Ppm copper levels? Btw. No rush in answering this.
Just a few notes. It sucks how long it takes to warm these engines. I'm a sitting duck on the road for 15 minutes or so. Also, the balky tranny and tall first gear both conspire to make you keep the car in second at low rpms. I try to ease the throttle slowly when accelerating. Scoring seems alll but unavoidable. At least we can run till we get excessive oil consumption or piston slap.
I've got no oil consumption nor slap yet. Only just to wait for the inevitable.
You mentioned seeing more bearing failures with thicker oil. Any advice on oil test results? Bad Ppm copper levels? Btw. No rush in answering this.
Just a few notes. It sucks how long it takes to warm these engines. I'm a sitting duck on the road for 15 minutes or so. Also, the balky tranny and tall first gear both conspire to make you keep the car in second at low rpms. I try to ease the throttle slowly when accelerating. Scoring seems alll but unavoidable. At least we can run till we get excessive oil consumption or piston slap.
I've got no oil consumption nor slap yet. Only just to wait for the inevitable.