I said "some" closed chamber designs. I was just at Shady dell speed shop a couple weeks ago and I was shown a 3 way comparison between a w2 open chamber,Indy 360-1, and 360-2. Both Indys are closed chamber but the 360-2 shape is very different than the 1
Ryan claims the chamber shape in the 2 restricts the flow compared to the 1. The 360-1 around the valves where the airflow counts looks like a w2. Ryan also told me that he has a hard time explaining chamber function to customers. Again the w2 was way ahead of its time. Also part of the benefit to a closed chamber is the ability to get a decently high compression ratio with a flat top piston which now is a lightweight piston.
