---------------------------------------------------------- Kolb-List Digest Archive --- Total Messages Posted Thu 06/21/12: 8 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:26 AM - rotax 447 propeller recomendation high temps (tombaisley) 2. 06:06 AM - Re: rotax 447 propeller recomendation high temps (Richard Pike) 3. 06:27 AM - Re: rotax 447 propeller recomendation high temps () 4. 06:50 AM - Re: rotax 447 propeller recomendation high temps (Beauford) 5. 06:52 AM - Re: rotax 447 propeller recomendation high temps (tombaisley) 6. 03:35 PM - Landing gear (axle material) (dutrac) 7. 03:41 PM - Re: Landing gear (axle material) (Richard Girard) 8. 07:41 PM - Slipping turn (joepilot503) ________________________________ Message 1 _____________________________________ Time: 04:26:47 AM PST US Subject: Kolb-List: rotax 447 propeller recomendation high temps From: "tombaisley" I have a FS1 w/ 447 2.58 box, spinning a 66" two blade IVO. I am have trouble with high EGT and CHT. With the propeller pitched to give me 6200rpm at climb out ,I'm seeing EGT in the 1100-1150 at 5700rpm which seems to cause the CHT to start climbing thru 400F. If I increase the prop pitch to 6000 rpm at climb out my EGT are stable at 1050 or so, but I'm still seeing CHT of 390-410F. I also have high EGT ( 1150 - 1230 ) in the 3900-4600rpm range, I suspect that may just be the nature of the beast. I spoke with IVO prop and his recommendation was "more pitch", But that seems to aggravate the CHT. I'm starting to wonder if I'm over propped and should maybe cut down the diameter or go to a three blade prop? Read this topic online here: http://forums.matronics.com/viewtopic.php?p=376194#376194 ________________________________ Message 2 _____________________________________ Time: 06:06:34 AM PST US Subject: Kolb-List: Re: rotax 447 propeller recomendation high temps From: "Richard Pike" You are running stock jets and have pressure/vacuum tested your engine I assume? Do you have an intake silencer? Because it will cause you to lose a hair of power, and IMO you can't afford to lose any power, because you already have too much prop. Back in the day when I had a 532 on the MKIII, IVO started me out with a 3 blade 64" - that was way too much prop for that engine, took one blade off and it was a sweetheart. Then I put a 2 blade 66" on it and that was good too. If I remember correctly (HAH) my buddies ran 3 blade 62" IVO's on their 503's. I am running a 68" 2 blade on my 582, and you are trying to run almost as much prop on a much smaller engine, so I would guess you are way overloaded on prop. Before I spent any money on another prop, I would start by shortening your current blades a bit at a time and see what happens. I suspect that when you get down around 62" - 64" you will find things to be OK assuming that all else is as it should be. -------- Richard Pike Kolb MKIII N420P (420ldPoops) richard (at) bcchapel(dot)org Kingsport, TN 3TN0 Now faith is the substance of things hoped for, the evidence of things not seen. Hebrews 11:1 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=376200#376200 ________________________________ Message 3 _____________________________________ Time: 06:27:49 AM PST US From: Subject: Re: Kolb-List: rotax 447 propeller recomendation high temps ---- tombaisley wrote: > I'm starting to wonder if I'm over propped and should maybe cut down the diameter or go to a three blade prop? Tom B/Folks: I prop a Kolb by flying straight and level, wide open throttle. A correctly propped engine should turn the max continuous red line. This will give best cruise and climb performance with a fixed or ground adjustable prop. I flew a 60X30 Culver two blade fixed pitch prop on my original Firestar and 447. This gave me 6500 rpm straight and level, WOT. john h mkIII Burns Junction, OR ________________________________ Message 4 _____________________________________ Time: 06:50:03 AM PST US From: "Beauford " Subject: RE: Kolb-List: rotax 447 propeller recomendation high temps I have a FS1 w/ 447 2.58 box, spinning a 66" two blade IVO. I am have trouble with high EGT and CHT. I suspect that may just be the nature of the beast. ------------------------- Brother Baisley: I run exactly the same 447/gearbox/prop combination as you, sir... My prop is loaded to yield exactly the same rpm on climb out as yours... My EGT/CHT temps mirror yours exactly.... I have, after much carburetor twiddling, fan fumbling, prop pitch changes, a thermocouple replacement festival, and several sessions of peering and poking at rings through exhaust ports, finally come to the conclusion that the little Nazi S.O.B. just likes to run hot. I don't know, but strongly suspect, that performing a carbon-fiber circumcision on your IVO won't solve the problem; that is just another way to reduce prop loading and the effects of that upon the EGT/CHT balance is already known and understood. Am pretty sure there is no free thermal lunch hiding in there anywhere. I place the issue of chronic 447 overheating in the same category of intractable problems as matrimony, stagflation and oversize prostates. They are built into the bedrock of the universe and we might as well get used to 'em... Accordingly, I have perfected and adopted the Beaufordian school of 447 operational philosophy... i.e. run the chrome-plated hell out of the damn thing and don't worry about it. It works fer me... may not work fer you... I think of it as rather like Dr. Stangelove's approach... Quit worrying about the Bomb and learn to love it. Worth what ye paid fer it... Do Not Archive Overheated beauford FF-076 Brandon, FL p.s. Brother B: Should you come across the 447 holy grail and figure out how to make it run cooler, please write home and share it without delay... b. ________________________________ Message 5 _____________________________________ Time: 06:52:29 AM PST US Subject: Kolb-List: Re: rotax 447 propeller recomendation high temps From: "tombaisley" I'm running stock jets, needle, and clip position. No intake silencer, stock exhaust. I replaced the head, base, intake, and exhaust gaskets. I had found that the spark plugs were cross threaded and not sealing. I have not pressure tested, but this engine is very fresh Read this topic online here: http://forums.matronics.com/viewtopic.php?p=376207#376207 ________________________________ Message 6 _____________________________________ Time: 03:35:37 PM PST US Subject: Kolb-List: Landing gear (axle material) From: "dutrac" Hi Folks, I have a Kolb MKII that I've given a few hard landings. The axles have bent and I've used a hydrolic press to straighten them once. After doing so it wasn't but a couple landings later that I noticed they were pretty well bent again. I talked to a factory rep and he told me that they don't recommend straightening them more than once. Whether right or wrong, I'm going to listen to that advice and replace them both. My question to the group then is what grade of aluminum are the axles made out of? Any help is appreciated. Thanks! Duane Read this topic online here: http://forums.matronics.com/viewtopic.php?p=376255#376255 ________________________________ Message 7 _____________________________________ Time: 03:41:46 PM PST US Subject: Re: Kolb-List: Landing gear (axle material) From: Richard Girard 7075-T6 Rick Girard On Thu, Jun 21, 2012 at 5:35 PM, dutrac wrote: > > Hi Folks, > > I have a Kolb MKII that I've given a few hard landings. The axles have > bent and I've used a hydrolic press to straighten them once. After doing so > it wasn't but a couple landings later that I noticed they were pretty well > bent again. > > I talked to a factory rep and he told me that they don't recommend > straightening them more than once. Whether right or wrong, I'm going to > listen to that advice and replace them both. > > My question to the group then is what grade of aluminum are the axles made > out of? > > Any help is appreciated. > > Thanks! > Duane > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=376255#376255 > > -- Zulu Delta Mk IIIC Thanks, Homer GBYM It isn't necessary to have relatives in Kansas City in order to be unhappy. - Groucho Marx ________________________________ Message 8 _____________________________________ Time: 07:41:06 PM PST US Subject: Kolb-List: Slipping turn From: "joepilot503" Does anybody out there with a Kolb do slipping turns from downwind to landing? I was doing them in a j-3 and want to try it in my firestar but a friend of mine didn't think it was a wise thing to do, or to be a legitimate maneuver. any feedback appreciated. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=376280#376280 ------------------------------------------------------------------------------------- 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.