---------------------------------------------------------- Kolb-List Digest Archive --- Total Messages Posted Sat 03/19/11: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:50 PM - slow day on the list (robert bean) 2. 12:56 PM - Re: 3 bladed Warp Drive propeller, RK-400 release question ? (Dennis Thate) 3. 01:21 PM - Re: slow day on the list (Larry Cottrell) 4. 06:58 PM - Muffler crack (Richard Pike) ________________________________ Message 1 _____________________________________ Time: 12:50:22 PM PST US From: robert bean Subject: Kolb-List: slow day on the list Here is the original incarnation of N3851E that I flew for 25 years. forgive the editing, trying to chop it down to youtube's 15 minutes ain't easy. http://www.youtube.com/watch?v=M39q-pbdn-o BB Kolb MkIII, N3851E ________________________________ Message 2 _____________________________________ Time: 12:56:28 PM PST US Subject: Kolb-List: Re: 3 bladed Warp Drive propeller, RK-400 release question ? From: "Dennis Thate" Thanks for all the private responses . You've answered my concerns. -------- Both optimists and pessimists contribute to our society. The optimist invents the airplane and the pessimist the parachute. ~Gil Stern Faith is believing what you know ain't so - Mark Twain Read this topic online here: http://forums.matronics.com/viewtopic.php?p=334446#334446 ________________________________ Message 3 _____________________________________ Time: 01:21:41 PM PST US From: "Larry Cottrell" Subject: Re: Kolb-List: slow day on the list It looked like a fairly comfortable plane to fly. I can't imagine my flight instructor in his 150 allowing me to fly like that. Thanks for the video Larry Note: If you forward this email, please delete the forwarding history, which includes my email address. ----- Original Message ----- From: robert bean To: kolb Sent: Saturday, March 19, 2011 1:47 PM Subject: Kolb-List: slow day on the list Here is the original incarnation of N3851E that I flew for 25 years. forgive the editing, trying to chop it down to youtube's 15 minutes ain't easy. http://www.youtube.com/watch?v=M39q-pbdn-o BB Kolb MkIII, N3851E 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= 3D ________________________________ Message 4 _____________________________________ Time: 06:58:25 PM PST US Subject: Kolb-List: Muffler crack From: "Richard Pike" During preflight this afternoon I found a crack in the muffler/expansion pipe junction of my 582 muffler. This same general area has caused me problems before with different Rotax engines, and has also caused several other local flyers crack problems in this same place. Attached is a picture of the muffler after I welded it and after I got done flying for the day. Thought about taking a picture before I welded it, but it was already 6 PM, and I wanted to just fix it and go. Welded it on the airplane, obviously haven't painted it yet. The red line is where the crack was, discovered the crack by first seeing exhaust carbon residue that had come out of it. Since the airplane was already out on the runway in front of the hangar, rolled the welding cart with the oxy/acetyline tanks out to the airplane. Once I got the metal red hot, I could see the crack was at least an inch longer to the left and 2.5 inches longer to the right than the original crack appeared to be, so it was progressing. My MKIII uses what they call the "Quicksilver" style expansion pipe, this is the first time I have seen a problem with this style, all the other failures have been with the "Curlyque" sidemount style like the Kolbs typically use, and have involved 447, 503 and 532 engines. On those, the failure typically begins on the weld along the outside of the pipe, the pipe splits along the edge of the welded flat seam and then the pipe begins to crack and separate around the junction of the pipe and muffler. Several of us have discussed this and it is our opinion that the pressure pulses eventually fatigue the welded joint and cause a crack. However, one of the failures was on a 503 about 12 years ago and in that one there were two cracks that started right in the rounded side of the curlyque. Apparently that portion of the pipe takes a lot of pressure pulse abuse. Ed and I discussed this for a while this afternoon, because he has a curlyque on his FSII, and you cannot see the front side of the welded seam from the rear of the wing. The only way you can see it is to stand on a stool in front of the wing and look over the wing to see it, but IMO, this ought to be a checklist item, because we have seen enough of them go bad that it is an obvious weak point. And if you are flying and it occurs to you that maybe your engines is a bit louder than it was - find a suitable place to land and check this area out. When the whole side half of the curlyque came loose on my 532, I was 5 miles from home, and by the time I got on the ground, the only thing holding that half of the curlyque expansion pipe to the airplane was the area adjacent to the ball joint, everything else had already broken. The Ivoprop would not have been happy... AND IT WAS LOUD! The wife heard me coming 3 miles away... From inside the house... With the doors and windows shut... So if your Rotax 2-stroke suddenly gets really loud - land. Unless you have a metal sheathed Warp Drive prop that can suck up that detached half, (good test, eh?) and would prefer to just buy a new cone for $200 rather than repair yours. Then you can keep going... Richard Pike MKIII N420P (420ldPoops) Read this topic online here: http://forums.matronics.com/viewtopic.php?p=334472#334472 Attachments: http://forums.matronics.com//files/crack_large_228.jpg ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message kolb-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Kolb-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/kolb-list Browse Digests http://www.matronics.com/digest/kolb-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.