Originally Posted by saintnoir
Okay i finally found a couple of machine shops that i can get valve stems made.One does nothing but prototypes the other is curious on making them in small run batches.
What i was hoping to find out is what the going rate is on them,and if anyone had pictures of broken ones so i can show them the failure points?
G7 valve stems are solid hardened steel with a plastic ring. I can't see any situation that would cause the valve stem to 'fail'. Like doc said, the plastic ring gets deformed over time and then ceases to make a good air tight seal. Also of note, you can't simply machine a valve stem like the OEM parts. They have the machined stem that is then overmolded with the plastic part. That way there is metal on both sides so the plastic can't fall off. Then you have the sealed spring and stem part of the valve stem. It would be very costly to reproduce OEM style valves IMHO.
I've toyed with the idea of making some solid delrin valve stems like a longer A1 D-lite valve stem and use Speed/A4 spring retainers. A valve stem like that could be machined easily. I would look into that if you are interested in making replacement valves for the G7.