Seeing more 997.2 failures? I am...
03-06-2019, 09:43 AM
#46
Bruce, Lokasil was the solution to their problems of fast machining a block with high silicon only in the areas of the cylinders and helped them recover their finances but created some minor issues that damaged the reputation of that model run.
But once they abandoned Lokasil they didn't need the high pressure castings and so they could return to a closed deck block, get rid of the IMS, remove the crankshaft overhang at the flywheel end and machine all the crankshaft bearings and RMS in one pass making sure they were all in line. All of these earlier issues were not good design practice (including the IMS sealed bearing) and they got rid of them all in one go, making a much better cylinder block and engine (although more expensive to produce).
Baz
But once they abandoned Lokasil they didn't need the high pressure castings and so they could return to a closed deck block, get rid of the IMS, remove the crankshaft overhang at the flywheel end and machine all the crankshaft bearings and RMS in one pass making sure they were all in line. All of these earlier issues were not good design practice (including the IMS sealed bearing) and they got rid of them all in one go, making a much better cylinder block and engine (although more expensive to produce).
Baz
03-06-2019, 10:04 AM
#47
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Bruce, Lokasil was the solution to their problems of fast machining a block with high silicon only in the areas of the cylinders and helped them recover their finances but created some minor issues that damaged the reputation of that model run.
But once they abandoned Lokasil they didn't need the high pressure castings and so they could return to a closed deck block, get rid of the IMS, remove the crankshaft overhang at the flywheel end and machine all the crankshaft bearings and RMS in one pass making sure they were all in line. All of these earlier issues were not good design practice (including the IMS sealed bearing) and they got rid of them all in one go, making a much better cylinder block and engine (although more expensive to produce).
Baz
But once they abandoned Lokasil they didn't need the high pressure castings and so they could return to a closed deck block, get rid of the IMS, remove the crankshaft overhang at the flywheel end and machine all the crankshaft bearings and RMS in one pass making sure they were all in line. All of these earlier issues were not good design practice (including the IMS sealed bearing) and they got rid of them all in one go, making a much better cylinder block and engine (although more expensive to produce).
Baz
Peace
Bruce in Philly
03-07-2019, 10:12 AM
#49
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I see what ya did there!! ^^
03-07-2019, 10:13 AM
#50
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I just ordered some Driven DI40. Got an email that said it was backordered from LN. Hope the "2 weeks" prediction is correct. I need to do an oil change soon.
Hoping the switch will give me peace of mind and work to protect the engine better.
Thanks for the info.
David
Hoping the switch will give me peace of mind and work to protect the engine better.
Thanks for the info.
David
03-07-2019, 06:17 PM
#51
An IMS shaft to transfer energy in an engine is not problematic. Porsche has been using an intermediate shaft successfully since the '60s. The problematic part was a "lifetime" sealed bearing at one end. The original, 30 year IMS design had a plain bearing at each end. A plain bearing is a pressurized oil fed bearing. Speculation is that Porsche did away with the oil feed on one end to cut costs (it is "correct" at the other end BTW). Baz notes that the "best" option is to install an oil feed system... what the engine should have had all along. The "repair" from Porsche should have been to redesign this bearing. Instead, they designed an entirely new block. Why they did this and not fix the M96/M97 block is a bit of a mystery to me. Maybe some new innovations came along such as eliminating the shaft among others but I just don;t know and have not read much about this decision.
Like you, I wonder why Porsche waited 10 years to truly fix the problem, especially when they were finally making so much darn money. This, I believe, was a strategic decision to "cash in" on the brand. The brand carried the ill will through this period. This is of course a risky business decision but they did the "right" thing from the investor's perspective. In other words, they delayed the true repair to save even more hard money at the possible expense of hurting the brand (which apparently did not happen). Heck, I had two failures and then what did I do? I rewarded them by buying another. If I felt there was another substitute, I would never have purchased another one but there are really no short wheel base, relatively light, multi-use, unique looking, luxury sport cars out there. (Actually Porsche isn't either, its become a GT car, but that is another flame-invoking subject.)
Peace
Bruce in Philly
Like you, I wonder why Porsche waited 10 years to truly fix the problem, especially when they were finally making so much darn money. This, I believe, was a strategic decision to "cash in" on the brand. The brand carried the ill will through this period. This is of course a risky business decision but they did the "right" thing from the investor's perspective. In other words, they delayed the true repair to save even more hard money at the possible expense of hurting the brand (which apparently did not happen). Heck, I had two failures and then what did I do? I rewarded them by buying another. If I felt there was another substitute, I would never have purchased another one but there are really no short wheel base, relatively light, multi-use, unique looking, luxury sport cars out there. (Actually Porsche isn't either, its become a GT car, but that is another flame-invoking subject.)
Peace
Bruce in Philly
Last edited by user 72902; 03-10-2019 at 06:38 AM.
03-10-2019, 08:16 AM
#52
With Porsche reportedly probably going out of business in the early '90's and the family reportedly stumping up the main to try and save the company and with the biggest issue being extremely old fashioned production methods and engine designs not suited to modern mass production techniques - the "rescue" had to optimise a relatively small cash injection to cover the cost of tooling and production methods that quickly turned a profit.
Designing an engine for multiple capacities was part of the plan to optimise tooling but also using the same heads for both banks was another obvious way to half costs - but meant they had to have a drive from both ends of the cylinder block.
I think this is why they ended up with the overhung flywheel end and that end of the IMS needing support at the flywheel flange end of the block where it would indeed be costly to drill long holes in to provide an oil feed (or the additional cost of external feeds).
I think this is probably why we ended up with the IMS bearing.
However the shaft could have had a solid oil fed bearing inboard and allow the chain sprockets to overhang.
I still have no idea why it had seals (or more accurately shields) except if it was to prolong shelf life to increase production runs by protecting the bearing from dust and the elements or why after fitting the much larger and more solid later bearing - it retained those shields unless it was to make sure the bearing was free from condensation between building it and someone buying and driving it?
Both the cylinder block and crank carrier are of course in 2 parts each.
Baz
.
Designing an engine for multiple capacities was part of the plan to optimise tooling but also using the same heads for both banks was another obvious way to half costs - but meant they had to have a drive from both ends of the cylinder block.
I think this is why they ended up with the overhung flywheel end and that end of the IMS needing support at the flywheel flange end of the block where it would indeed be costly to drill long holes in to provide an oil feed (or the additional cost of external feeds).
I think this is probably why we ended up with the IMS bearing.
However the shaft could have had a solid oil fed bearing inboard and allow the chain sprockets to overhang.
I still have no idea why it had seals (or more accurately shields) except if it was to prolong shelf life to increase production runs by protecting the bearing from dust and the elements or why after fitting the much larger and more solid later bearing - it retained those shields unless it was to make sure the bearing was free from condensation between building it and someone buying and driving it?
Both the cylinder block and crank carrier are of course in 2 parts each.
Baz
.
03-23-2019, 02:26 PM
#54
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997.2 cooked
Finally bought my 1st Porsche. 2009 9114S. From a dealer last year. 60,000km.... 1 year to the date I start it up for a 1st spring drive and rough idle. Have it towed in to dealership (not one I purchased from) and apparently I have to replace the short block. $ 70,0000 for the car an a year later 14k for engine work.
CPO of course ended last July (4 months after purchasing). So Unhappy... never a warning light, noise nothing. It had under CPO both cooking fans replaced (seized), high pressure fuel pump (failed), new brakes, new cooling lines (with fans),.. this was my “get into Porsche car” ... drive for a couple years and move up to a 2013 or up...
CPO of course ended last July (4 months after purchasing). So Unhappy... never a warning light, noise nothing. It had under CPO both cooking fans replaced (seized), high pressure fuel pump (failed), new brakes, new cooling lines (with fans),.. this was my “get into Porsche car” ... drive for a couple years and move up to a 2013 or up...
03-23-2019, 02:38 PM
#55
Finally bought my 1st Porsche. 2009 9114S. From a dealer last year. 60,000km.... 1 year to the date I start it up for a 1st spring drive and rough idle. Have it towed in to dealership (not one I purchased from) and apparently I have to replace the short block. $ 70,0000 for the car an a year later 14k for engine work.
CPO of course ended last July (4 months after purchasing). So Unhappy... never a warning light, noise nothing. It had under CPO both cooking fans replaced (seized), high pressure fuel pump (failed), new brakes, new cooling lines (with fans),.. this was my “get into Porsche car” ... drive for a couple years and move up to a 2013 or up...
CPO of course ended last July (4 months after purchasing). So Unhappy... never a warning light, noise nothing. It had under CPO both cooking fans replaced (seized), high pressure fuel pump (failed), new brakes, new cooling lines (with fans),.. this was my “get into Porsche car” ... drive for a couple years and move up to a 2013 or up...
03-23-2019, 03:29 PM
#57
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Any discussion of Toyota and Porsche should also include the Boxster. Boxster saved Porsches **** but is was the Toyota engineers they hired to teach them how to cut costs and make it very profitable. Transaxel era hurt Porsche real bad and they needed a lower cost car. And to bring the 911 back.
03-23-2019, 04:16 PM
#58
What really stabilized the company before VW took over Porsche was the introduction of their Cayenne and then moving into the luxury sport sedan market with the Panamera. The sports car market, whether the 911, the Boxster or a Corvette, is extremely cyclical and dangerous to a company that makes only sports cars.
Now that Porsche makes more SUVs than sports cars, will the brand lose focus and be just another luxury brand?
Now that Porsche makes more SUVs than sports cars, will the brand lose focus and be just another luxury brand?
03-23-2019, 05:31 PM
#59
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So horrible for a 1st and maybe last Porsche...
