---------------------------------------------------------- Stratus-List Digest Archive --- Total Messages Posted Fri 09/09/05: 1 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 08:02 AM - Re-Pitch to 17-degrees on a 601 with a Stratus (Grant Corriveau) ________________________________ Message 1 _____________________________________ Time: 08:02:24 AM PST US Subject: Stratus-List: Re-Pitch to 17-degrees on a 601 with a Stratus From: Grant Corriveau --> Stratus-List message posted by: Grant Corriveau (Note: I don't have the Stratus, but the CAM100 (Honda). However, due to the small numbers of CAMs flying in the 601, I tend to monitor this list because of the similarities with the Subaru engine). So -- for what it's worth on this discussion, I also found that my engine does better than I'd expected as I increase the prop pitch. (Warp Drive; 3 blades; tapered ends; CAM100 rated at 100 hp at 6,000eng/2,500prop RPM. I have had the prop up to 18 degrees and found, as Larry reports, excellent cruise performance with little noticeable loss of takeoff and climb performance. I attribute this to the torque gained at the prop through a PSRU (ratio 2.4/1), and also perhaps the Warp Drive prop's apparent characteristic of twisting aerodynamically under various loads. My max rpm at takeoff (i.e. static) with the prop currently set at 15 degrees is 5,000 rpm. When I had 18 degrees max (static) rpm dropped only by about 100 rpm or so -- barely noticeable. I eventually backed off from 18 because I 'imagined'? that the engine was lugging a little -- but I'm not certain of that. It may just have been an aerodynamic vibration that was occuring at cruise speeds...? With respect to fuel consumption, vs. power with automotive carburettors. My engine has a stock Honda carb which means a second barrel that opens towards full throttle. I have installed a K&N mixture monitor, and I've found that in cruise at 2,500 feet, 5,000 rpm gives a 'normal' mixture setting (one green led lit), but if I throttle back just a tad to 4900 the mixture leans out 'one notch' to show all the amber led's illuminated but no green led's illuminated. At this setting the fuel consumption works out to about 3.5 USG/hour and the aircraft maintains 105+ mph. Not bad, especially at current fuel prices! So for each engine, finding that spot where the automotive carb leans out just a touch, is probably a good place to fly for maximum range. Hope some of this is helpful to Stratus pilots. As Red Green would say: "... I'm pulling fer ya. We're all in this together." -- Grant Corriveau C-GHTF / HDS / CAM100