I have built up a small but complete flight testing regime on two different KR-2's and have never had anything remotely like a torque induced tendency to roll. Both of my planes have extra engine. One is a Subaru, and it is as tame and gentle as a little girl, the other has a Saturn engine and it is wild with a mountain of extra power and speed but no tendency to roll on take off or any other time. Seems to me that it should have been noticed by now. What do people think of the high torque from an O-200, then? Interested in comments Jim
James E. Sellars, B.A., (Econ.), CFP International Financial Planner Keybase Financial Group Inc. 120 Queen St, Moncton, N.-B. Canada E1C-1K7 Phone: (506) 856-7977 | Fax: (506) 859-8504 Email: [email protected] [email protected] Web: www.WealthManagementCanada.com -----Original Message----- From: [email protected] [mailto:[email protected]] Sent: July 9, 2009 3:19 AM To: [email protected] Subject: KR> Suburu engines - something to consider Probably the biggest reason to avoid higher-powered engines in KR's is the problem with immediate and fatal torque rolls once the wheels leave the runway. Using a PSRU with a Suburu and its extra torque this tendency would even be worse. When KR's just had VW's, torque rolls after takeoff were not a serious problem, but once the horsepower started to go up, the fatal torque rolls started. Among those first fatalities was Homer Didit of Mena, Arkansas who put that R-985 in his KR-2. He only made the one flight and augered in on takeoff. And what about that fellow with the turbine KR? I haven't seen or heard about it for quite some time now. Torque roll on takeoff? I never see this phennomenon discussed on these forums. Is it something we just don't like to talk about? The 300 lb. gorilla sitting in the corner? I think it's time people gave this deadly KR quirk some attention so that new pilots won't be caught unawares when they push that throttle forward. I'm sure the Corvair people will correct me if I'm wrong, but seems like there have been a flock of KR's with Corvair six cylinder engines that torque-rolled in - pulling it off too soon with full throttle. Torque-roll. Boom. Smoke. There's just too much temptation to firewall the throttle and try and show off with a vertical climb when you have all that power available. Remember, these planes are made of styrofoam. Hanging a huge engine on the front is just asking for trouble. What got me started on this train of throught was that I've always wondered why one of my tires wears out before the other one. Landing on one tire more than the other would explain it, except at my home field the normal crosswind would favor wearing out the tire on the upwind side, not the one that actually wears. The difference is not great, but it's noticable and consistent. It wasn't until I came across this piece by John Deakin in his column Pelican's Perch on Avweb that I realized what is happening. "But in something like the Bearcat, the power is much higher, the torque is correspondingly greater, and the wings are shorter, giving less leverage. I assure you, the roll is there, and it's very noticeable. Left tires wear out much sooner on the Bear." Since our engines mostly turn to the left, our tires wear out on the other side - the right side. Even with our puny little engines (compared to the warbirds the article is about), there is enough of a difference over time to wear out the right tire more than the left one. And so another mystery is solved. Mike Deakin's articles are really a wealth of good info on many aviation topics, for those who haven't yet come across him. http://www.avweb.com/news/pelican/182146-1.html ____________________________________________________________ Do it right the first time. Click to find contractors to work on your home improvement project. http://thirdpartyoffers.juno.com/TGL2141/fc/BLSrjpTJuto6rnBOmCgGYlS13zPERXEr fpZvzqKPxXRaRJf1ceV3ih9bfTS/ _______________________________________ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to [email protected] please see other KRnet info at http://www.krnet.org/info.html
