Many different inverted drum valve timmings & back plate timmings have been tested. These balanced (done in a magnetic balancer); full hard & flash chrome plated on the OD, induction valves, are extremely durable. They have been tested at 32,000+ rpm with no failures. Bushing material used is B-1 or B-2 phosphor bronze. Back plates made of 2024-T351 aluminum do not require any bushing.
