X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mx2.netapp.com ([216.240.18.37] verified) by logan.com (CommuniGate Pro SMTP 5.4.5) with ESMTPS id 5555415 for flyrotary@lancaironline.net; Wed, 23 May 2012 09:43:43 -0400 Received-SPF: none receiver=logan.com; client-ip=216.240.18.37; envelope-from=echristley@att.net X-IronPort-AV: E=Sophos;i="4.75,645,1330934400"; d="scan'208";a="649766542" Received: from smtp2.corp.netapp.com ([10.57.159.114]) by mx2-out.netapp.com with ESMTP; 23 May 2012 06:43:10 -0700 Received: from [10.62.16.167] (ernestc-laptop.hq.netapp.com [10.62.16.167]) by smtp2.corp.netapp.com (8.13.1/8.13.1/NTAP-1.6) with ESMTP id q4NDh7e5024420 for ; Wed, 23 May 2012 06:43:09 -0700 (PDT) Message-ID: <4FBCE931.7040908@att.net> Date: Wed, 23 May 2012 09:42:09 -0400 From: Ernest Christley Reply-To: echristley@att.net User-Agent: Thunderbird 2.0.0.24 (X11/20100623) MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: Graduated to high power run-ups References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Lehanover@aol.com wrote: > So at each 100 RPM both advance and retard timing from the set point to > see that you are in the middle of a range for that RPM. You may find > some nulls that like a bit of retard. This is usually a combination of > header and inlet tract design. Your combination is not like anyone else > even if they look identical. I have played with the timing just a little bit. On the computer I have to adjust by 0.1* at a time. I didn't see much of a change as I moved it up and down by 0.5 to 1.0 degree. I thought there would be more benefit to getting the AFR smoothed out, so I left it alone for now. How large of a change in advance is necessary to start showing up on the tach? > > Cylinder pressure developed BTDC subtracts from torque, so less is more > in the timing department. > > Target water temp is 180. Oil temp is 160. Above 160 oil is giving away > power, as rotor face temps go way up and limit charge volume. So, oil > temp control is free HP. > > 1600 degrees goes with about 12.5 FA in most cases. So far, I've only been able to give the EGTs an occasional glance to insure I'm not melting anything. They and the oil pressure gauge are mounted to my left, and everything else is on the computer on my right. Since I'm doing this in my suburbian driveway, I have to keep my head moving looking for the stray soccer ball (no actual kids around, but you never know). The highest EGT I've seen so far is around 1500 (I need to tilt the gauge to eliminate parallax error). I've got a line on some hangar space at a grass field 10 minutes from my house. Then I'll be able to be a little more studious of all the engine parameters. > > Advancing the throttle from fast idle to full power should be smooth and > slow. If the timing is fixed this is very important. For closed throttle > and near closed throttle, with poor cylinder filling fixed 20 or 22 > degrees is fine but if you romp down on the power quickly that 20 > degrees is way to much as wide open throttle at low RPM gets you nearly > 100% or slightly more cylinder filling. if(WOT & (RPM < 4000){ ADV <= 15 } Setting the computer is easy. Knowing WHAT the setting should be.... > > Record everything. Currently, the only thing I'm not recording is the EGTs. I have individual probes for each rotor, but I'm considering adding another probe, installing it at the exit of the exhaust collector, and tying it into the MegaSquirt so that I can record it along with everything else. I would tie the two I have into the computer, but I only have one ADC port left on it. Would a combined EGT reading be valuable when it is recorded alongside all the engine temps, timing, AFR, RPM, throttle position, etc? > > This information may be worth what it cost you. You do realize I'm printing out your advice and keeping it with me as I work over the tuning 8*)