991 GT3 9000 RPM Engine Tech
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991 GT3 Hydro Lifters - 9000 RPM !?
OK geeks, engineers and motorheads... Is there any detailed info floating around out there regarding the new hydraulic lifters that can deal with 9000 RPM? Any info yet on the rocker arm ratio and/or cam dynamics?
Any detailed engine "cut-ways" showing the valve train details? I can't make out the lifter or rocker design from this one. There's probably a larger version of this out there.
![](http://carsguns.com/wp-content/uploads/2013/03/porsche-991-gt3-engine.jpg)
I found Herr Preuninger's video interesting when he presented the rocker arm design as unique or somehow beyond what other engines were doing. Surely Porsche is familiar with the American V8 engine
So perhaps there is something else unique about their design?
OK geeks, engineers and motorheads... Is there any detailed info floating around out there regarding the new hydraulic lifters that can deal with 9000 RPM? Any info yet on the rocker arm ratio and/or cam dynamics?
Any detailed engine "cut-ways" showing the valve train details? I can't make out the lifter or rocker design from this one. There's probably a larger version of this out there.
![](http://carsguns.com/wp-content/uploads/2013/03/porsche-991-gt3-engine.jpg)
I found Herr Preuninger's video interesting when he presented the rocker arm design as unique or somehow beyond what other engines were doing. Surely Porsche is familiar with the American V8 engine
![Wink](https://rennlist.com/forums/images/smilies/wink.gif)
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I'm pretty sure that the Ferrari F355 had both 8500+RPM hydraulic lifters and rocker arms.
And I'm no expert on motorcycles, but I though they were using rocker arms on most of the 'special' overhead cam bikes to get the proper valve geometry - and packaging. I'd assumed that this was what Porsche was trying to do with this 9A1 derivative.
And I'm no expert on motorcycles, but I though they were using rocker arms on most of the 'special' overhead cam bikes to get the proper valve geometry - and packaging. I'd assumed that this was what Porsche was trying to do with this 9A1 derivative.
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Yes, important when going up to 9k rpm. It can be without the rocker and the hydro can be in between cam and valve directly, just like in convensional DOHC setup. But, this will make the head higher.
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i reminisce though, and found this video. for those that don't know, peter brock was killed around 10 years ago in an accident when competing in a tarmac rally.
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991 GT3 Hydro Lifters - 9000 RPM !?
OK geeks, engineers and motorheads... Is there any detailed info floating around out there regarding the new hydraulic lifters that can deal with 9000 RPM? Any info yet on the rocker arm ratio and/or cam dynamics?
Any detailed engine "cut-ways" showing the valve train details? I can't make out the lifter or rocker design from this one. There's probably a larger version of this out there.
![](http://carsguns.com/wp-content/uploads/2013/03/porsche-991-gt3-engine.jpg)
I found Herr Preuninger's video interesting when he presented the rocker arm design as unique or somehow beyond what other engines were doing. Surely Porsche is familiar with the American V8 engine
So perhaps there is something else unique about their design?
OK geeks, engineers and motorheads... Is there any detailed info floating around out there regarding the new hydraulic lifters that can deal with 9000 RPM? Any info yet on the rocker arm ratio and/or cam dynamics?
Any detailed engine "cut-ways" showing the valve train details? I can't make out the lifter or rocker design from this one. There's probably a larger version of this out there.
![](http://carsguns.com/wp-content/uploads/2013/03/porsche-991-gt3-engine.jpg)
I found Herr Preuninger's video interesting when he presented the rocker arm design as unique or somehow beyond what other engines were doing. Surely Porsche is familiar with the American V8 engine
![Wink](https://rennlist.com/forums/images/smilies/wink.gif)
I thought that the revisions to the lifter design were because in years past they had variable valve timing on intake and exhaust. The new 991 motors have variable lift and duration on the intake side and I'm assuming they went a step further on the GT3 to enhance the variable valve clearance OR they're trying to mimic what's available on the street car to create more power opportunity? Specualtion...i'm not an expert NOR am a Porsche employee. I'm just the guy in the trenches.