The -C drive has very different internals but I will look at the feasibility of reworking the -B housing to receive the -C guts. I think it can be done. Yes, the -C bolts right up to the same adapter plate. I think you are right about the 2.85 becoming the preferred ratio, but only if you can handle the longer prop. You nose draggers have the advantage here. The more I fly it the better I like this setup. The higher rpm was very disconcerting at first but I acclimated rapidly. And now that I have digested the fact that the actual rpm difference at normally used throttle settings is only about 5%, I absolutely love it. Another good sign is that the manifold pressure is now more than 5% lower at any given airspeed that I've tested so far. Even if the wear rate is up 5% or so it would be a non issue. One more plus for the 2.85 is something I hesitate to mention. It's kind of like the "engine making oil so I have to drain some out" thing, kind of unbelievable. It makes sense that there would be less prop noise but I'm also getting less engine noise. I was getting tired of the increased noise with the Hushpower II muffler and was almost ready to put the Spintech back on even though it costs at least 5 - 6 mph in drag. But with the -C drive things have quieted down substantially. I think part of the credit for this goes to the difference in RPM moving the vibrations away from the resonance point of the sheet metal panels in my RV-4 but even observers on the ground have mentioned that the engine sounds quieter. I better shut-up now, this is starting to sound too good to be true. Tracy ----- Original Message ----- From: Ed Anderson Sent: Monday, March 22, 2004 8:30 AM To: Rotary motors in aircraft Subject: [FlyRotary] C mounting on a B plate?? Renesis & RD-1C drivetesting Sounds great thus far, Tracy Imagine having so much thrust that you can't hold the aircraft still for maximum static, must be tough {:>). If you initial observations hold regarding fuel consumption and performance, then I predict the 285 will soon become the standard. If the fuel burn/performance is a wash then only engine wear from higher rpm might be a factor, but since the rotary seems to only have no/ minimum wear in any case, that probably will not be a significant factor. So how much are you given for 2.17:1 trade ins? Seriously, will the B model mounting plate accommodate the C model gear box housing (looks like you mount it the same way). I presume it would not be so simple as swapping out the internals as I am certain the internal mounting/housing is different in the two. Third, in case you consider getting rid of that old performance prop, put me on top of your list. Ed
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