I'm just going to chime in here. I've been running the Mejzlik 18x6 on the OS 1.60fx / BCM Pitts muffler / Perry VP30 pump. I'm getting about 9300 RPM (slightly rich) on the ground at 1000' ASL, on a 65 degree day. I'm using 15% nitro, 18% castor/synthetic Wildcat fuel. The Mejzlik spools up quickly and though I haven't tried any other props with this engine (yet) I'm very happy with the Mejzlik...and the OS in general. Flying it on a GSP Katana.

-Tom