A quick update on testing with the new top end and exhaust on N1213W. I finally got the downgraded engine back together with the new exhaust and started flying it just before Christmas. Due to some travel over the Christmas and New Years holidays and a lingering headcold, I haven't put but 4 1/2 hours on it so far. However, the following are my conclusions of the performance changes with the stock O-200 vs the high compression O-200 (C-85 pistons) and the new exhaust with the tuned headers.
My first impression is that the RPMs and the rate of climb are definitely off a bit. The engine is down maybe 50 RPMs from what it turned with the C-85 pistons. I credit that to changing the compression back to a stock O-200. I'm still whining about that situation. :o0 However, the top speed is just a tiny bit faster than it was before. I would credit that to the better breathing exhaust I built for the engine. <http://www.losalamos.com/jscott/KR/exhaust.html> Previously, with the old exhaust, the head pipes for cyls #1 and #2 had a lot of turbulence and resistance to flow as well as an overall poor design. The engine seemed to labor at full throttle, high speed operations. It wasn't smooth and didn't feel good under those conditions. Now the engine is much smoother under the same conditions and actually seems to wind up a bit more and may have resulted in a slight increase in top speed in level flight. My testing has all been at 9500' so far. At full throttle operations, I have been seeing from 147 to 151 mph IAS depending on fuel loads, which trues up to 173.5 - 178 mph (151.5 - 154.7 kts) Previously, I was topping out at 170 mph. Jeff Scott Los Alamos, NM N1213W ____________________________________________________________ Click here to learn more about nursing jobs. http://thirdpartyoffers.juno.com/TGL2141/fc/PnY6rw2bVNX8jt4PBzPfaR6qLRU2608VLpa73stsQnC20nDPiKFji/
