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Message: Re: Porsche tried many times unsuccessfully to develop a 4-valve technology on . . .
Changed By: John Brown of SE SoDak
Change Date: December 30, 2010 02:35PM
Re: Porsche tried many times unsuccessfully to develop a 4-valve technology on . . .
Change Date: December 30, 2010 02:35PM
Re: Porsche tried many times unsuccessfully to develop a 4-valve technology on . . .
their air cooled engines. The 4-valve heads experienced too much extreme heat and the valves & guides couldn't tolerate that. 4-valve engines were necessary for modern engines to breathe sufficiently to satisfy emission requirements. Also, the greater heat ranges of air cooled engines make engine management much more challenging, again especially in regards to controlling emissions.
All of this and probably more in addition to the noise issues.
For what it's worth here, Harley-Davidson is experiencing the same challenges with their Twin Cam and Evolution lines of 2-valve, air cooled engines. Their newest model, the VRSC or V-Rod bike, employs a water-cooled, 4-valve engine developed at Weissach by Porsche. For Harley as well as for Porsche, water cooling is the way of the future. (along with all of the unintended consequences that will be inevitable). I hope H-D can learn from Porsche's expeniences . . .
All of this and probably more in addition to the noise issues.
For what it's worth here, Harley-Davidson is experiencing the same challenges with their Twin Cam and Evolution lines of 2-valve, air cooled engines. Their newest model, the VRSC or V-Rod bike, employs a water-cooled, 4-valve engine developed at Weissach by Porsche. For Harley as well as for Porsche, water cooling is the way of the future. (along with all of the unintended consequences that will be inevitable). I hope H-D can learn from Porsche's expeniences . . .
Changed By: John Brown of SE SoDak
Change Date: December 30, 2010 02:29PM
Re: Porsche tried many times unsuccessfully to develop a 4-valve technology on . . .
Change Date: December 30, 2010 02:29PM
Re: Porsche tried many times unsuccessfully to develop a 4-valve technology on . . .
their air cooled engines. The 4-valve heads experienced too much extreme heat and the valves & guides couldn't tolerate that. 4-valve engines were necessary for modern engines to breathe sufficiently to satisfy emission requirements. Also, the greater heat ranges of air cooled engines make engine management much more challenging, again especially in regards to controlling emissions.
All of this and probably more in addition to the noise issues.
For what it's worth here, Harley-Davidson is experiencing the same challenges with their Twin Cam and Evolution lines of 2-valve, air cooled engines. Their newest model, the VRSC or V-Rod bike, employs a water-cooled, 4-valve engine developed at Weissach by Porsche. For Harley as well as for Porsche, water cooling is the way of the future.
All of this and probably more in addition to the noise issues.
For what it's worth here, Harley-Davidson is experiencing the same challenges with their Twin Cam and Evolution lines of 2-valve, air cooled engines. Their newest model, the VRSC or V-Rod bike, employs a water-cooled, 4-valve engine developed at Weissach by Porsche. For Harley as well as for Porsche, water cooling is the way of the future.
Original Message
Author: John Brown of SE SoDakDate: December 30, 2010 02:28PM
Re: Porsche tried many times unsuccessfully to develop a 4-valve technology on . . .
their air cooled engines. The 4-valve heads experienced too much extreme heat and the valves & guides couldn't tolerate that. 4-valve engines were necessary for modern engines to breathe sufficiently to satisfy emission requirements. Also, the greater heat ranges of air cooled engines make engine management much more challenging, again especially in regards controlling emissions.
All of this and probably more in addition to the noise issues.
For what it's worth here, Harley-Davidson is experiencing the same challenges with their Twin Cam and Evolution lines of 2-valve, air cooled engines. Their newest model, the VRSC or V-Rod bike, employs a water-cooled, 4-valve engine developed at Weissach by Porsche. For Harley as well as for Porsche, water cooling is the way of the future.
All of this and probably more in addition to the noise issues.
For what it's worth here, Harley-Davidson is experiencing the same challenges with their Twin Cam and Evolution lines of 2-valve, air cooled engines. Their newest model, the VRSC or V-Rod bike, employs a water-cooled, 4-valve engine developed at Weissach by Porsche. For Harley as well as for Porsche, water cooling is the way of the future.