19.01.2014, 11:59
Die Firma Linamar (ex McLaren Tochter bis 2003) fertigt und assembliert diese Köpfe. Die LS7 Köpfe sind die einzigen GM Köpfe die je siamesed valve seats haben und das einsetzen der Sitze ist dadurch etwas schon mal spezielles.
hier ein paar Bilder....
![[Bild: cl3n1tgzjcqwdgtwc.jpg]](https://666kb.com/i/cl3n1tgzjcqwdgtwc.jpg)
![[Bild: cl3n2825mgtkeno7w.jpg]](https://666kb.com/i/cl3n2825mgtkeno7w.jpg)
und hier ein Originaltext, lest genau wie die Sitze gefrässt werden:
After the seats are installed, they are machined to the proper angles. On the all-important intake, starting at the combustion chamber roof, the seat angles are: 39°, 45°, 60° and 71.83° followed by a radius. The exhaust seats are cut with 38.17°, 45° and 76° angles, then a radius. In both cases, the valve face seats on the 45° portion. Each seat and radius are machined by one milling tool in a single plunge movement of the 5-axis CNC's table.
das heisst nichts anderes das alle Sitze nach einem festen CNC Programm und dessen Koordinaten gefrässt werden und nicht wie bei auf einer Serdi100 mittels Dorn geführt. Wenn es nun nur den leisesten Aufspannversatz gibt kann sich der Fehler aufakkumulieren und zum Konzentritzitätsversatz führen.
auch ganz interessant:
The same protective, CrN coating used on the connecting rods is on the intake valves but getting that coating just right was a tough task for Jim Hicks and the engineers working on the LS7 valvetrain. One of the issues they had to address was a "Ti dust wear" problem, similar in nature to what afflicted the connecting rod development. When the CrN coating wasn't right, it would fail and highly-abrasive Ti dust would develop between the valve stem and guide causing rapid guide wear. "Developing the stem coating which was going to work well with our production-style, PM guides was another challenge. Most racers use bronze guides or some other type of aftermarket guide which is cost-prohibitive. A moly-sprayed stem, which is typically used a lot on titanium valves (for racing), is very expensive. We wanted to come up with an alternative, so we worked on a chrome-nitride, vapor deposition coating. It took a little development, but it worked out really well for us. It was more cost-effective and just as good or better than the moly spray. There's some tricks to that process and we worked with Del West in developing them. The parts need to be very, very clean. The right processing steps need to be used. The coating thickness is very important and needs to be maintained to a tight tolerance. I think Del West is using it now for some of their aftermarket parts, too."
hier ein paar Bilder....
und hier ein Originaltext, lest genau wie die Sitze gefrässt werden:
After the seats are installed, they are machined to the proper angles. On the all-important intake, starting at the combustion chamber roof, the seat angles are: 39°, 45°, 60° and 71.83° followed by a radius. The exhaust seats are cut with 38.17°, 45° and 76° angles, then a radius. In both cases, the valve face seats on the 45° portion. Each seat and radius are machined by one milling tool in a single plunge movement of the 5-axis CNC's table.
das heisst nichts anderes das alle Sitze nach einem festen CNC Programm und dessen Koordinaten gefrässt werden und nicht wie bei auf einer Serdi100 mittels Dorn geführt. Wenn es nun nur den leisesten Aufspannversatz gibt kann sich der Fehler aufakkumulieren und zum Konzentritzitätsversatz führen.
auch ganz interessant:
The same protective, CrN coating used on the connecting rods is on the intake valves but getting that coating just right was a tough task for Jim Hicks and the engineers working on the LS7 valvetrain. One of the issues they had to address was a "Ti dust wear" problem, similar in nature to what afflicted the connecting rod development. When the CrN coating wasn't right, it would fail and highly-abrasive Ti dust would develop between the valve stem and guide causing rapid guide wear. "Developing the stem coating which was going to work well with our production-style, PM guides was another challenge. Most racers use bronze guides or some other type of aftermarket guide which is cost-prohibitive. A moly-sprayed stem, which is typically used a lot on titanium valves (for racing), is very expensive. We wanted to come up with an alternative, so we worked on a chrome-nitride, vapor deposition coating. It took a little development, but it worked out really well for us. It was more cost-effective and just as good or better than the moly spray. There's some tricks to that process and we worked with Del West in developing them. The parts need to be very, very clean. The right processing steps need to be used. The coating thickness is very important and needs to be maintained to a tight tolerance. I think Del West is using it now for some of their aftermarket parts, too."
_____________________________________________________________
CCRP Austria, Bundesstrasse 100, 8402 Werndorf
CCRP Austria, Bundesstrasse 100, 8402 Werndorf