Is the 928 100% a Porsche design?
#61
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#62
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#63
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Reason why alusil worked better in Porsche engines than on Vega motor was casting process. Problem in Vega was that when block was cast two materials would not stay uniformly mixed until casting solidified. This lead to uneven casting where silicone wasn't present in needed quntity on some spots. Result was same as what happens when overbored 928 cylinder walls aren't properly done.
Famous Cosworth DFV 3L F1 V8 engine had solved this problem already years before Vega problems by turning casting upside down during its cool down period. This made sure material distribution was uniform in areas where it mattered. Porsche or more likely actually Mahle solved same problem by controling how casting cooled down. Same process has been used in many other engines. More info about the process is available for example in this document.
https://trid.trb.org/view.aspx?id=197260
http://papers.sae.org/830003/
http://www.w124performance.com/docs/...nditioning.pdf
Famous Cosworth DFV 3L F1 V8 engine had solved this problem already years before Vega problems by turning casting upside down during its cool down period. This made sure material distribution was uniform in areas where it mattered. Porsche or more likely actually Mahle solved same problem by controling how casting cooled down. Same process has been used in many other engines. More info about the process is available for example in this document.
https://trid.trb.org/view.aspx?id=197260
http://papers.sae.org/830003/
http://www.w124performance.com/docs/...nditioning.pdf
#64
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#65
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The Bosch CIS injection used on the early cars has traceable history to the Kugelfisher (sp?) mechanical injection found in some 1960's M-B cars, among others. Bosch bought the company and rights, refining it into the CIS system we all know and love.
Remember also that Porsche was contracting assembly services to M-B for some of their performance models. They had hands-on (literally) access to the developments at M-B. I can speculate that the decision to build the 928 was influenced by the number of premium-priced S500 they assembled for Mercedes.
Last but not least, engineers and even more so designers/drafters are a shifting labor pool. As Tony Lapine and his group came over from GM in Europe, I'm sure that group also included folks who had penned designs for other companies including M-B. Safe to say I think that the styling and a lot of the execution was revolutionary, a massive amount was/is evolutionary. Consider that engineering is a science of avoiding making the same mistakes again. The design and engineering target that is the 928 undoubtedly started with a list of requirements, and also a list of things that were to be avoided.
Remember also that Porsche was contracting assembly services to M-B for some of their performance models. They had hands-on (literally) access to the developments at M-B. I can speculate that the decision to build the 928 was influenced by the number of premium-priced S500 they assembled for Mercedes.
Last but not least, engineers and even more so designers/drafters are a shifting labor pool. As Tony Lapine and his group came over from GM in Europe, I'm sure that group also included folks who had penned designs for other companies including M-B. Safe to say I think that the styling and a lot of the execution was revolutionary, a massive amount was/is evolutionary. Consider that engineering is a science of avoiding making the same mistakes again. The design and engineering target that is the 928 undoubtedly started with a list of requirements, and also a list of things that were to be avoided.
#66
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The core of my question really was, and is, are there any parts on the 928 that were designed by another auto manufacture and either used as is or modified for use in the 928? So for example, parts designed and built by Bosch don't count because Bosch doesn't build cars. So far the only part identified that meets this criteria is the automatic transmission, which has its roots in a MB design and was not a 100% clean sheet design by the big brains at Porsche.
I find this thread completely fascinating. Not only about all the details, but I am blown away by the depth of knowledge that you guys have.
#67
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If Bosch doesn't count, does Porsche count? Plenty of small parts from the 911 bin found their way into various areas of the 928. That was back on page 1-ish. If by page 5 we haven't beat this to death, one could say that the 'clean-sheet' became stained along the way with some small leftovers from the 911. But - only a complete **** retentive would make note of it.
Wait - whut? gggrrrrrrrrr.
Wait - whut? gggrrrrrrrrr.
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Interesting read is the Porsche type 542 , the FIRST 4 door Porsche , First with a water cooled V-6 yes V -6 at 120 degrees no less ! , quite a history .....it was nearly "clean sheet" too !
#69
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On another couple of notes while I'm in the mood, the follow-on from BMW which was a similar design process was the BMW 850. Although not as divorced from the prev line as the 928 was, going in a complete different direction with engine/trans layout, and switching from air to water cooling, the 850 project spent a shilt-load of money on design and development. It was one of BMWs greatest financial flops on record.
The 928 was as different from prev cars from Porsche as it could possibly be. Which is what engenders the 'clean-sheet' kind of statements. Compared to today's badge engineered crapola from the big 3 in the US where entire platforms are shared across lines it was definitely and departure of certain magnitude.
The 928 was as different from prev cars from Porsche as it could possibly be. Which is what engenders the 'clean-sheet' kind of statements. Compared to today's badge engineered crapola from the big 3 in the US where entire platforms are shared across lines it was definitely and departure of certain magnitude.
#70
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Reason why alusil worked better in Porsche engines than on Vega motor was casting process. Problem in Vega was that when block was cast two materials would not stay uniformly mixed until casting solidified. This lead to uneven casting where silicone wasn't present in needed quntity on some spots. Result was same as what happens when overbored 928 cylinder walls aren't properly done.
Famous Cosworth DFV 3L F1 V8 engine had solved this problem already years before Vega problems by turning casting upside down during its cool down period. This made sure material distribution was uniform in areas where it mattered. Porsche or more likely actually Mahle solved same problem by controling how casting cooled down. Same process has been used in many other engines. More info about the process is available for example in this document.
https://trid.trb.org/view.aspx?id=197260
http://papers.sae.org/830003/
http://www.w124performance.com/docs/...nditioning.pdf
Famous Cosworth DFV 3L F1 V8 engine had solved this problem already years before Vega problems by turning casting upside down during its cool down period. This made sure material distribution was uniform in areas where it mattered. Porsche or more likely actually Mahle solved same problem by controling how casting cooled down. Same process has been used in many other engines. More info about the process is available for example in this document.
https://trid.trb.org/view.aspx?id=197260
http://papers.sae.org/830003/
http://www.w124performance.com/docs/...nditioning.pdf
Yep,,, that was a "unique and original" Porsche engineering process
Last edited by DoubleNutz; 05-04-2016 at 05:11 PM.
#71
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If Bosch doesn't count, does Porsche count? Plenty of small parts from the 911 bin found their way into various areas of the 928. That was back on page 1-ish. If by page 5 we haven't beat this to death, one could say that the 'clean-sheet' became stained along the way with some small leftovers from the 911. But - only a complete **** retentive would make note of it.
Wait - whut? gggrrrrrrrrr.
Wait - whut? gggrrrrrrrrr.
Last I checked Bosch is is not an automobile manufacturer... or could I be wrong in that someone is driving a Bosch out there.
Of course Porsche used some of its racing and heritage engineering from the 911 to design the 928, why wouldn't they???
#72
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#73
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It is never been unusual for Porsche to do this, it fact, it is my understanding that Porsche has even contracted with BMW to build body parts for the 996 and had help from Toyota to design the 996 and Boxster.
#74
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The Porsche name is credited for many engineering firsts industry wide across all automobile manufacturers for something that may be built today under another manufacturer marque.
#75
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