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Discussion Starter #1
https://www.youtube.com/watch?v=Jv-5gF9QZfA&sns=em

Ford Performance Engineers developed a balanced combination of high end, 580 horsepower and strong mid-range torque with the Cobra Jet intake manifold, unique camshafts and fully CNC ported GT350 cylinder heads.

"I have never experienced an engine that can handle such abuse. I have used this motor in 2 different vehicles since it was launched. I have used it in naturally aspirated form and also put boost to it making 700HP and 900HP to the wheels. We set the rev limit at 7800 RPM and it lives on. One motor is going on 3 years old. Despite the constant abuse, I have never experienced a failure with the Aluminator XS. I would consider it bulletproof."- Vaughn Gittin, Jr.


Ford Performance 5.2L Aluminator XS Crate Engine -- M-6007-A52XS
 

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Discussion Starter #3 (Edited)
A dozen years of technology improvement certainly helps. Still missing a couple of cylinders. :)
Agreed
The Mustang sells in enough volume that it has a much better business case for continued development.
It would still be interesting to see what Ford keyed on to acheive high rpm reliability.
Could it be as simple as a well engineered crankshaft that addresses torsional harmonics and resonant vibration while at high rpm

I can see that the ROI for engineering and development for the s85 would be a much tougher sell to BMW (for profit) management at the relatively low production volume.

Some additional resources may have been available during the v10 F1 engine program but that ended early.

Once the high speed engine concept was determined to not be economical for the future no further development investment was likely made.


I keep thinking back to the non destructive testing of the s85 crankshaft design via statistical analysis:

http://www.m5board.com/vbulletin/attachments/e60-m5-e61-m5-touring-discussion/453017d1407024816-s85-crankshaft-design-optimization-presentation-um07_bmw_hinderer_06.pdf

Back then simulation and modeling software was inferior to current state of art.

But could have been a necessary cost saving in order to make the business case for the e60 m5
 

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Discussion Starter #5 (Edited)
in the vid Justin Pawlak corroborates "no failures" even though he leaves rev limiter at 8500 rpm and uses off the shelf crate motor with no dry sump.

I find this amazing, perhaps i am too easily impressed

No way with VW diesel gate etc a big corporation would allow lies about this, way too much to loose for perhaps a few extra crate motors sold.
These may be loss leaders anyway to support racing and mod community, thus no sense mis-representing the performance.

I can see the motivator when trying to sell $130,000 vettes but look at all the class actions GM got in return.

Just not worth it, risking a 100-yr + brand
 

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Discussion Starter #7
I don't think revving high has a significant effect on reliability.

Honda engines have been revving to 9000 rpms from much earlier without any reliability issues.

Granted, but much smaller lighter pistons and connecting rods thus much less load on bearings.

I was looking to compare a motor that had heavier reciprocating assembly thus bearing loads similar too or greater than s85 for any clues on what works at this level of bearing stress.


however the small displacement Honda 4-cyl and 6-cyl are still interesting since they did use F1 tech as well, perhaps better at making it work in a production car than BMW:


"The forged steel crankshaft is micro-finished, an extremely precise finishing process developed originally from the Formula One engine program to reduce friction and enhance durability. The metallurgy of the main bearings is also a direct result of Honda's F1 program of the late eighties and early nineties. The surface of the bearings has a unique, pyramidal structure, allowing space for enhanced oil retention and resulting in lower friction and improved long-term durability."


Honda F20C engine | Why it is so special, tuning and specs
 

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I don't think revving high has a significant effect on reliability.

Honda engines have been revving to 9000 rpms from much earlier without any reliability issues.
A good point. However, like Ticat mentioned, the loads of a light 4-cyl can't be compared, not only internally, but externally also.
Keep in mind the F20C DID have reliability problems, which is a reason that they dropped the fuel cut from 9000 rpm to 8200 in the F22C1, which I believe was in 2004. Obviously a slightly larger displacement motor (.2L), but they also needed to drop the compression a bit, too - and we're talking only a 2800 lb car.
Another apples to oranges comparison would be a ZX14 or similar. A 1.4L motor that revs to 11,000 rpm with 12.3:1 compression. Obviously, that can run all day because the internals are so light, and it only needs to push around 600 lbs (plus rider, of course).
 

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A good point. However, like Ticat mentioned, the loads of a light 4-cyl can't be compared, not only internally, but externally also.
Keep in mind the F20C DID have reliability problems, which is a reason that they dropped the fuel cut from 9000 rpm to 8200 in the F22C1, which I believe was in 2004. Obviously a slightly larger displacement motor (.2L), but they also needed to drop the compression a bit, too - and we're talking only a 2800 lb car.
Another apples to oranges comparison would be a ZX14 or similar. A 1.4L motor that revs to 11,000 rpm with 12.3:1 compression. Obviously, that can run all day because the internals are so light, and it only needs to push around 600 lbs (plus rider, of course).

I am not aware of any reliability problems with the F20C.

I thought they reduced the engine speed on the F22C because of the piston velocity and not because of the rpms.

I agree on the weight of the internals being a factor. But the weight of the vehicle is rather irrelevant.
 
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