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Someone earlier called it a race engine. (Won't mention names, but it wasn't me) But wierdly, it's the only v10 street engine with no racing history.
 

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It was me
I am sticking with my opinion

short stroke, same bore centers as F1 motor
Same Dual Rad individual head cooling process
Same foundry as F1 motor
Tested to 10,000 rpm
Block good for a lot more hp
 

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Clearances are looser, not tighter under race conditions
High RPM doesn't go with loose clearances, that will break the oil film. Race engines do have tight clearances pistons and bearings.
The S85 is NOT a race engine
ok let's call it street race engine or high performance engine.
There is even no high performance engine porsche back in the days of the natually aspirated era untill 2010, high performance engine 100hp/liter, only 996 with a twin turbo can be faster than any M3 or M5 despite the aerodynamic of the porsche. The E39 M5 with KNN filters,back exhaust box, and a software change will blow any 966 twin turbo ( This is proven fact ).
 

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oh, and my 02 996 IS faster than a n an M3, and out handles and out brakes one while returning better mpg, without valve adjustments, rear tub tearing, suspension dramas, etc. Your ignorance is shining through!
 

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I view the S85/65 as great big motorcycle engines. They are NOT bespoke race engines due to the fact that the bore spacing is whatever, or they are cast in the same foundry (probably Becker BTW).
Again, generally, larger clearances go with thicker oil and vice versa. These two fundamentals are important to correct bearing function, and all the other various things that are mentioned can not usually countermeasure incorrect choices in these two fundamentals.
 

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Correct
Race engines do not have to idle smoothly or pass emissions, l am still not going let go of the idea that there was some technology transfer from F1 program
 

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Actually emissions measurements are not uncommonly taken during development. This gives one a measure of bore distortion (HC). Obviously no F's are given about NOx!
 

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If we're talking f1 or endurance racing, I'm betting emissions are addressed. In the 80s fuel limits were placed on cars and Porsche began using catalytic converters on their racing cars. This stuff may not be important to Americans, but certainly to Europeans. I still remember seeing the light weight Audi A2 diesel that did north of 100 mpg. Audi was just as fond of that as they were their R8 Lemans racers of the time.
 

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Audi cheated like F with the diesels in the LeMans racing. They always went faster at night, hmmm.

In F1 and endurance racing engine development, emissions test equipment is used as I laid out.

Porsche most definitely did not use catalytic converters in their mid to late 00's P2 V8 prototype cars I can tell you that.
 

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The faster at night thing isn't unusual. You should know better than that. The air is colder, so more oxygen rich. All the cats become faster. As long as a driver feels comfortable, they run faster. Crazy comment, really. Curious, did you look at the Porsche exhaust? I actually wrenched on a GT1 back in the late 90s and they still had them then.
 

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Uh, no the faster at night thing was a big difference on the Audis. The rules stated that no visible exhaust gases are permissible. Hard to see Hans and Jurgen rolling coal at night.

I didn't comment on the Porsche GT class cars, I commented on their prototype class cars.
 

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This appears to have devolved into a Porsche thread but back to the S85, I dont think there are any of the engineers that worked on developing the S85 on this board so why bicker about the origins? It has a bearing issue I think we all agree just as we can agree we are all here because there is something alluring about a n/a V10 200mph family car.

As to lineage, BMW marketed it as being bread from their F1 experience, whether that was fact based in mechanical engineering or marketing based on the same number of cylinders doesn't really matter to the rod bearings.
 

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Marketing, for sure, however I can tell you that the people that did the F1 engine were indeed involved in the S85. I had hoped to get to the bottom of it with a friend of mine at Indy, but this pandemic thing kind of got in the way.

Thank you for getting thread back on track I was starting to worry that "bystanders might not know the difference"...
 

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My bearing comments were in regards to not only the s85, but the rest of BMW's engines since. If this was limited to a limed short run production engine, that's one thing, but it appears to be an issue for all engines produced after the s85. BMW needs to be challenged on this as it really isn't reasonable.
 
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