RE: K&B .48 vs OS 46 VXDF
I have 200+ flights with the OS 46VXDF + Turbax I + MACS tuned pipe combination and the engine has performed flawlessly for every flight. In all of those flights, I had probably 3 dead stick landings and all of them were due to either running out of fuel or a failed throttle pushrod. The engine never once blew a plug. The only maintenance issues I have had have been periodic bearing changes.
The 46 VXDF is a very reliable, robust, powerful and user friendly engine. But the most important benefit of this engine is that it is in production and currently available.
The K&B 48 has been a "phantom engine" ever since it was "released", which was a single, very limited production run. Very few engines were ever made and it has not been available for several years, with no indication that that status will ever change in the future. JHH gave up pleading with MECOA to put the engine back into production several years ago.
Further discussion on this topic is pointless. If you want to fly .46 glow DF you really only have one (realistic) choice, and that is the OS 46 VXDF with either the Turbax or Thorjet fan units.
Regards,
Peter