---------------------------------------------------------- Kolb-List Digest Archive --- Total Messages Posted Tue 07/24/07: 26 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:48 AM - Re: needles for 447 (Thom Riddle) 2. 06:42 AM - Re: for us non-oshkoshers (robert bean) 3. 07:47 AM - Re: Re: needles for 447 (Vince Nicely) 4. 08:06 AM - xpndr in MkIIIC? (Robert Laird) 5. 08:13 AM - Re: xpndr in MkIIIC? (Richard Pike) 6. 08:44 AM - Re: needles for 447 (Thom Riddle) 7. 10:15 AM - Re: poly v belt (jb92563) 8. 12:06 PM - Recovery Pictures (Kirby Dennis Contr MDA/AL) 9. 01:09 PM - Re: Re: needles for 447 (Richard Girard) 10. 01:59 PM - Re: Recovery Pictures (JetPilot) 11. 02:05 PM - Fuel Efficiency ? was Re: Small Cross Country (planecrazzzy) 12. 02:06 PM - Re: xpndr in MkIIIC? (JetPilot) 13. 02:12 PM - Re: Seized 447 (JetPilot) 14. 02:18 PM - Re: Off To Oshkosh (JetPilot) 15. 02:45 PM - Re: xpndr in MkIIIC? (planecrazzzy) 16. 03:10 PM - Re: Re: Seized 447 (possums) 17. 04:03 PM - Posting pictures, was/: Off To Oshkosh (Eugene Zimmerman) 18. 05:00 PM - Re: Re: Seized 447 (beauford T) 19. 05:19 PM - Re: Fuel Efficiency ? was Re: Small Cross Country (Jack B. Hart) 20. 06:03 PM - Re: Re: Seized 447 (possums) 21. 06:58 PM - Re: needles for 447 (Thom Riddle) 22. 07:09 PM - Re: Seized 447 (lucien) 23. 07:13 PM - Fuel Efficiency ? was Re: Small Cross Country (lucien) 24. 07:59 PM - Re: Fuel Efficiency ? was Re: Small Cross Country (Eugene Zimmerman) 25. 08:09 PM - Re: Fuel Efficiency ? was Re: Small Cross Country (Eugene Zimmerman) 26. 09:34 PM - Re: Re: Seized 447 (possums) ________________________________ Message 1 _____________________________________ Time: 03:48:32 AM PST US Subject: Kolb-List: Re: needles for 447 From: "Thom Riddle" Rick, The engine was new last year and is immaculately clean, no seal leaks. The only range in which the EGTs are high is the mid-range. At the moment, with the clip in the #4 (richest position) the EGTs are around 1100 +/-25 at cruise. They are fine at idle and low throttle settings and WOT. I have not done an exhaustive intake leak test but will be looking into that while waiting for my jets and needles to arrive. I'm also going to mark on the throttle at 1/4, 1/2, 3/4 positions so I can get an idea of where the problem is occurring in terms of throttle position, not just RPM range. The biggest problem now is that I can't get it to hold a stable RPM below 5,500. When I got the FS the airscrew was back out a lot more than .5 as the Rotax manual recommends. I re-set it to stock and it would not run so I backed it out to where it was and it runs fine at low speed and idle. The idle speed was set rather low so I bumped it up to get about 2150 rpm when warm. When cold it is a good bit less than 2,000 rpm so I have to add throttle to keep the gearbox happy. If I set the idle speed for 2,000 rpm cold, then when warm it will be really revving and require brakes to stay still on the ramp. -------- Thom in Buffalo N197BG FS1/447 -------------------- "Blind respect for authority is the greatest enemy of truth." Albert Einstein Read this topic online here: http://forums.matronics.com/viewtopic.php?p=125466#125466 ________________________________ Message 2 _____________________________________ Time: 06:42:40 AM PST US From: robert bean Subject: Re: Kolb-List: for us non-oshkoshers Mike/all, pardon any delay in my posts as I now use the day old digest. You will be entirely satisfied with the 1.3 suzuki, a good power match for a MkIII. My 1.0 gives adequate performance in solo flight but starts to notice when the right seat is occupied. The easy fix is a "no fat chicks" placard. Going the suzuki route was a matter of curiosity for me, just to see if would work. Also some satisfaction contriving the various systems. The electrical was a total success. Cooling took some trial and error. Fuel and carb was a LOT of work, cutting down and adapting a carb, a lot of tied down run time at various throttle settings using a meter and O2 sensor. I'm probably at 90% of optimum now but once getting it running nice and reliable you can understand why a guy would give it a rest and just do some flying. I have very short runners on the intake and as a result the vaporization was incomplete. To compensate I made a water heated jacket to partially wrap the log section. It works well providing I wait until the engine is fully warmed up. I usually finish my preflight to use up the time. I will try some minor mixture adjustments to see if it can be improved. The last item will be an attempt to alter the cam timing. Designed for a car, the engine has peak torque at 3800 but peak hp at about 5500. From what I have read a slight retardation of the cam gear will shift the torque curve upward. It means taking some stuff apart which means down time, so that will wait for the return of winter. I'll probably scrounge a used gear to mutilate so I will still have a good one to fall back on. This year was the new doors which I am delighted with and for a quick fix in the climb department I took a little pitch out of the prop. Good 'nuff for now. BB do not archive ________________________________ Message 3 _____________________________________ Time: 07:47:32 AM PST US From: Vince Nicely Subject: Re: Kolb-List: Re: needles for 447 If you are considering trying different jet needles, you can find more information on how different needles may change the mixture in a graph in the CPS catalog. The Maintenance Tips article number 11, "Tuning the Bing Carburetor - Understanding the Mid-Range Circuit" has a lot of detail that may interest you. Vince Nicely Thom Riddle wrote: > >Thanks for the needle solutions for your cases. Following is what I did yesterday. > >I re-pitched the prop again, this time such that I am getting 6450 rpm at full throttle level flight.... just right. I then flew for 2.3 hours with two stops en-route. The EGTs were running around 1100 +/- 25 during 5500-5800 rpm cruise with no problems in that range. BUT the needle clip is in the #4 (richest) position. Below 5500 rpm the engine is still unstable with RPM varying all over the place. > >After the flight I checked the plugs and they are about right. I removed the carb and took it apart. All the jets and the jet needle are per Rotax spec and in good condition with less than 70 hours on engine. The float levels are perfect too. > >Today I plan to order a slightly richer needle jet (2.72 vs current 2.70) and one each of the two jet needles that you guys stated solved your problems. With three new pieces the combinations of possible parts is quite large. I'll test them each one at a time and then in various combinations, if needed. In each case I'll put the clip back in the #2 position to begin with. > >I'll let you know what finally works for me (I hope). > >-------- >Thom in Buffalo >N197BG FS1/447 > > ________________________________ Message 4 _____________________________________ Time: 08:06:16 AM PST US From: "Robert Laird" Subject: Kolb-List: xpndr in MkIIIC? Anyone here have a full-sized transponder installed in their MkIIIC ? I guess I could sell the xpndr I have and get one of those little ones that fit into 3" hole, but before I do that, I was just pinging the group to see if anyone's done it. Thx. -- Robert ________________________________ Message 5 _____________________________________ Time: 08:13:48 AM PST US From: "Richard Pike" Subject: Re: Kolb-List: xpndr in MkIIIC? You could always try and find an older Terra. Half as wide as a regular transponder. Pictures here - http://www.bcchapel.org/pages/0003/pg4.htm Richard Pike MKIII N420P (420ldPoops) ----- Original Message ----- From: "Robert Laird" Sent: Tuesday, July 24, 2007 11:05 AM Subject: Kolb-List: xpndr in MkIIIC? > > Anyone here have a full-sized transponder installed in their MkIIIC ? > I guess I could sell the xpndr I have and get one of those little > ones that fit into 3" hole, but before I do that, I was just pinging > the group to see if anyone's done it. > > Thx. > > -- Robert > > > ________________________________ Message 6 _____________________________________ Time: 08:44:37 AM PST US Subject: Kolb-List: Re: needles for 447 From: "Thom Riddle" Thanks Vince, I'm familiar with that graph. Though it is hard to read, a straight edge along the line for a particular jet needle helps clarify it. -------- Thom in Buffalo N197BG FS1/447 -------------------- "Blind respect for authority is the greatest enemy of truth." Albert Einstein Read this topic online here: http://forums.matronics.com/viewtopic.php?p=125493#125493 ________________________________ Message 7 _____________________________________ Time: 10:15:20 AM PST US Subject: Kolb-List: Re: poly v belt From: "jb92563" Poly V-belt 280j10 for Ultrastar redrive can be had for ~$5.00 ea at: http://kscdirect.com/item/PIX%2B280J10/280J10_J-POLY-V_BELT_28%2522_10_RIB Why pay more when you don't have to? Ray -------- Ray Riverside County, CA Do Not Archive Read this topic online here: http://forums.matronics.com/viewtopic.php?p=125511#125511 ________________________________ Message 8 _____________________________________ Time: 12:06:19 PM PST US Subject: Kolb-List: Recovery Pictures From: "Kirby Dennis Contr MDA/AL" Eugene Zimmerman asked: << How did you manage to "right" your inverted plane again once on firm dry ground without further damage? Did any mud or water enter your engine while inverted on the lake? >> Gene - When the helicopter set the plane down (inverted), it was only a matter of removing the wings and horizontal stabilizers, so that we could roll the airplane back onto its wheels. Took us about 30 minutes to do this. The worst that came of it was minor scratching on the Lexan door windows. No structural damage was incurred by rolling the wingless plane 180 degrees on the ground. (Adds to my confidence, regarding the level of structural integrity of the Kolb design!) Fortunately, no mud or water entered the engine. For those 2 days while the Kolb was on the lake bed upside down, the engine stayed just above the surface, out of the muck. The top-mounted muffler was the barrier - like a pontoon of sort, it kept the motor above the surface. I plan to remove the muffle and clean it out. But I'm confident the Rotax-912 will be OK. Dennis Do not archive ________________________________ Message 9 _____________________________________ Time: 01:09:23 PM PST US From: "Richard Girard" Subject: Re: Kolb-List: Re: needles for 447 Thom, Had a customer and his son here a few minutes ago and John, the son, described a problem virtually word for word of what you are experiencing with his single carb 503. The solution, credited to someone at South Mississippi was to increase the pitch of the prop to achieve about 6200 at WOT in flight. He said the CHT's came up and the EGT's came right down. At least I offer cheap ideas to try.:-) Rick On 7/24/07, Vince Nicely wrote: > > > If you are considering trying different jet needles, you can find more > information on how different needles may change the mixture in a > graph in the CPS catalog. The Maintenance Tips article number 11, > "Tuning the Bing Carburetor - Understanding the Mid-Range Circuit" has > a lot of detail that may interest you. > > Vince Nicely > > > Thom Riddle wrote: > > > > >Thanks for the needle solutions for your cases. Following is what I did > yesterday. > > > >I re-pitched the prop again, this time such that I am getting 6450 rpm at > full throttle level flight.... just right. I then flew for 2.3 hours with > two stops en-route. The EGTs were running around 1100 +/- 25 during > 5500-5800 rpm cruise with no problems in that range. BUT the needle clip is > in the #4 (richest) position. Below 5500 rpm the engine is still unstable > with RPM varying all over the place. > > > >After the flight I checked the plugs and they are about right. I removed > the carb and took it apart. All the jets and the jet needle are per Rotax > spec and in good condition with less than 70 hours on engine. The float > levels are perfect too. > > > >Today I plan to order a slightly richer needle jet (2.72 vs current 2.70) > and one each of the two jet needles that you guys stated solved your > problems. With three new pieces the combinations of possible parts is quite > large. I'll test them each one at a time and then in various combinations, > if needed. In each case I'll put the clip back in the #2 position to begin > with. > > > >I'll let you know what finally works for me (I hope). > > > >-------- > >Thom in Buffalo > >N197BG FS1/447 > > > > > > -- Rick Girard "Ya'll drop on in" takes on a whole new meaning when you live at the airport. ________________________________ Message 10 ____________________________________ Time: 01:59:09 PM PST US Subject: Kolb-List: Re: Recovery Pictures From: "JetPilot" I saw a trike pilot post and talk on his webpage about your accident, he flew over those dry lakes to try to find the place you landed, but could not. You can now consider youself famous in the ultralight world [Wink] Mike -------- "NO FEAR" - If you have no fear you did not go as fast as you could have !!! Kolb MK-III Xtra, 912-S Read this topic online here: http://forums.matronics.com/viewtopic.php?p=125551#125551 ________________________________ Message 11 ____________________________________ Time: 02:05:30 PM PST US Subject: Kolb-List: Fuel Efficiency ? was Re: Small Cross Country From: "planecrazzzy" Yep , your numbers look REAL close.... and I might add that I'm pretty "Happy" with them..... .. .. Gotta Fly... Mike & "Jaz" in MN .. .. .. -------- .. .. .. .. .. Do Not Archive Read this topic online here: http://forums.matronics.com/viewtopic.php?p=125552#125552 ________________________________ Message 12 ____________________________________ Time: 02:06:57 PM PST US Subject: Kolb-List: Re: xpndr in MkIIIC? From: "JetPilot" Yep, I have a full sized Garmin 327 transponder. I have read about some problems with the small ones that fit in the hole, and did not want any part of that. Since I fly in a lot of airspace where its required, with lots of traffic, I wanted a full performance transponder with no issues. I would hate to get rear ended by a Cessna. Mike -------- "NO FEAR" - If you have no fear you did not go as fast as you could have !!! Kolb MK-III Xtra, 912-S Read this topic online here: http://forums.matronics.com/viewtopic.php?p=125553#125553 Attachments: http://forums.matronics.com//files/ultralightmikekolbinstruments_191.jpg ________________________________ Message 13 ____________________________________ Time: 02:12:15 PM PST US Subject: Kolb-List: Re: Seized 447 From: "JetPilot" The belt breaking would cause High CHT's, and probably overheat the engine. An overheated engine like you are describing would not cause the belt to fail or stop working. Its a good idea to check that belt from time to time, for tension, slippage, and wear. That belt failure is going to be expensive for you, but just be glad it did not result in any damage to your plane or you. Mike -------- "NO FEAR" - If you have no fear you did not go as fast as you could have !!! Kolb MK-III Xtra, 912-S Read this topic online here: http://forums.matronics.com/viewtopic.php?p=125556#125556 ________________________________ Message 14 ____________________________________ Time: 02:18:35 PM PST US Subject: Kolb-List: Re: Off To Oshkosh From: "JetPilot" Eugene Zimmerman wrote: > > > JettPilot, > > It is even more "unreasonable" for you to be unwilling to click on a > link to see a picture if it will help another person be able to also > enjoy the Kolb List. Eugene, Many pictures are not available on the web. I post a fair number of pictures here, none of which are anywhere else on the web. Many people just have pictures in their computer that they want to share, without having to put up a web page. The forum based pictures are a great system. There is a VERY easy cure to this problem, just use the web based forum, you dont download the pictures unless you click on them. If someone MUST use the clunky, old email system, set your email client not to download attachments automatically. Either way, everyone is happy, and most of us can take advantage of being able to post and see pictures on the forum. Mike -------- "NO FEAR" - If you have no fear you did not go as fast as you could have !!! Kolb MK-III Xtra, 912-S Read this topic online here: http://forums.matronics.com/viewtopic.php?p=125559#125559 ________________________________ Message 15 ____________________________________ Time: 02:45:12 PM PST US Subject: Kolb-List: Re: xpndr in MkIIIC? From: "planecrazzzy" I don't have a Mark III , But I have the full size Narco AT 150 Transponder w/ AR850 Alt Encoder in my Firestar II... http://www.geocities.com/planecrazzzy/LSXXIX.html .. .. .. Gotta Fly... Mike & "Jaz" in MN .. .. .. -------- .. .. .. .. .. Do Not Archive Read this topic online here: http://forums.matronics.com/viewtopic.php?p=125561#125561 Attachments: http://forums.matronics.com//files/transponder_and_encoder_under_seat_324.jpg ________________________________ Message 16 ____________________________________ Time: 03:10:14 PM PST US From: possums Subject: Re: Kolb-List: Re: Seized 447 At 05:12 PM 7/24/2007, you wrote: > >The belt breaking would cause High CHT's, and probably overheat the engine. > >An overheated engine like you are describing would not cause the >belt to fail or stop working. Its a good idea to check that belt >from time to time, for tension, slippage, and wear. > >That belt failure is going to be expensive for you, but just be glad >it did not result in any damage to your plane or you. > >Mike Beauford Tuton described a similar problem with his 447 fan assembly. Something about the weld coming loose. I can't find it in the achives. ________________________________ Message 17 ____________________________________ Time: 04:03:13 PM PST US From: Eugene Zimmerman Subject: Kolb-List: Posting pictures, was/: Off To Oshkosh On Jul 24, 2007, at 5:18 PM, JetPilot wrote: > > > Eugene, > > Many pictures are not available on the web. I post a fair number > of pictures here, none of which are anywhere else on the web. > Many people just have pictures in their computer that they want to > share, without having to put up a web page. The forum based > pictures are a great system. > > There is a VERY easy cure to this problem, just use the web based > forum, you dont download the pictures unless you click on them. > > If someone MUST use the clunky, old email system, set your email > client not to download attachments automatically. > > Either way, everyone is happy, and most of us can take advantage of > being able to post and see pictures on the forum. > > Mike > > -------- > "NO FEAR" - If you have no fear you did not go as fast > as you could have !!! > > Kolb MK-III Xtra, 912-S JetPilot, Here is one excellent example of how it is done without causing anyone a problem. A new Email List Photo Share is available: Poster: Dennis Kirby Lists: Kolb-List,Ultralight-List Subject: "Magic Bike" Recovery Pictures http://www.matronics.com/photoshare/Dennis.Kirby@kirtland.af.mil. 07.22.2007/index.html ________________________________ Message 18 ____________________________________ Time: 05:00:25 PM PST US From: "beauford T" Subject: Re: Kolb-List: Re: Seized 447 Possum, Sir: That problem was with the weld on the recoil starter, not with the fan... my little "overheat" was gummed up rings during the 447 Nazi Carbon Festival, Spring of '05, it was... led directly to the "green dot" piston epiphany over at the Lockwood Castle... As I recollect, a minor part malfunction with the famous Bing Brothers apparatus brought about that particular episode... (same engine though.... gotta love them there 447's... real character builders) Anyone care for another glass of Seafoam...? Do not archive Beauford FF076 / N173BW Brandon, FL ----- Original Message ----- From: possums Beauford Tuton described a similar problem with his 447 fan assembly. Something about the weld coming loose. I can't find it in the achives. Web Forums! ________________________________ Message 19 ____________________________________ Time: 05:19:11 PM PST US From: "Jack B. Hart" Subject: Re: Kolb-List: Fuel Efficiency ? was Re: Small Cross Country At 09:14 PM 7/23/07 -0400, you wrote: >I'm interested in finding out what others are experiencing in fuel >efficiency. Eugene, I have a FireFly with a Simonini Victor 1+ mounted. I had never taken any data above 5,600 rpm because it is uncomfortable to cruise at any rpm higher than that. I have not been able to achieve the Simonini published fuel flow rates at 5,600 or lower. You can see my efforts to lean the engine out on the bottom of: http://www.thirdshift.com/jack/firefly/firefly121.html Last Saturday morning was my EAA Chapter 373 meeting, and I was a little late getting off. For the first time, I let the engine cruise at 6,000 rpm. I climbed to 2,870 feet asl to reach 55 degree F air to be sure that coolant temperatures would stay within specs. Ground to ground flight time was 54 minutes and total fuel burn was 1.90 gallons for an overall fuel burn of 2.11 gph. Distance between airports is 23 miles and assuming an additional mile for pattern distance, the total distance traveled was 48 miles. This gives 25.3 mpg. 2.11 gph at 6,000 rpm agrees with Simonini's published data for the Victor 1+. I have two EGT probes mounted. The second is mounted down stream from the first by about six inches. When running the engine at 5,500 rpm the down stream EGT probe will normally run 100 degrees higher than the engine mounted probe. This is pretty constant down to about 4,500 rpm. But when I cruised at 6,000 rpm the down stream probe read 400 degrees higher. Now that I have had time to think about it, I believe what happened is the engine was running up on the pipe. I believe the engine is falling off the pipe tuning if it is run at 5,500 rpm. I will be making some more runs at 5,900, 5,800 etc. rpm to see what happens. If this is the case, I can lengthen the pipe or inject water to try an get better fuel economy at 5,500 rpm. Several years ago, I took some ground data on the Rotax 447 while injecting water, and I found that it did reduce fuel flow. It would be interesting to try this while flying to see what happens. If you would like to see this data, it can be seen at: http://www.thirdshift.com/jack/firefly/firefly58c.html Always more to do. Jack B. Hart FF004 Winchester, IN ________________________________ Message 20 ____________________________________ Time: 06:03:13 PM PST US From: possums Subject: Re: Kolb-List: Re: Seized 447 At 07:59 PM 7/24/2007, you wrote: >Possum, Sir: >That problem was with the weld on the recoil starter, not with the >fan... my little >"overheat" was gummed up rings during the 447 Nazi Carbon Festival, > >(same engine though.... gotta love them there 447's... real >character builders) They are "character builders" that's for sure. Mine used to hunt like a bird dog any where under 5400 rpm. It was the old point ignition system though. It is amazing to me what a difference a dual carb 503 made in my life. I don't know if it's because of the two carburetors or just because it's a bigger engine (the extra 10 hp come in handy too). Still set up like it cam out of the box. Mine just stays put unless you pull the nose up or down, of course. Have 738 hours now - and I know it needs a rebuild, but I think it'll make it to 800 hours - then I'll throw it away and buy a new one. I can still get'um wholesale, so it's worth it just for the new muffler and shiny carbs. ________________________________ Message 21 ____________________________________ Time: 06:58:54 PM PST US Subject: Kolb-List: Re: needles for 447 From: "Thom Riddle" Rick, I already did that but then the engine rpm instability below 5500 rpm was made worse. At 6450 WOT rpm the EGTs are around 1100 +/25 at cruise which is much better than before the changes made so far, but the engine rpm instability below 5500 is still present. I'm awaiting new jets and needles to see if I can find a combination that solves all the problems. -------- Thom in Buffalo N197BG FS1/447 -------------------- "Blind respect for authority is the greatest enemy of truth." Albert Einstein Read this topic online here: http://forums.matronics.com/viewtopic.php?p=125595#125595 ________________________________ Message 22 ____________________________________ Time: 07:09:23 PM PST US Subject: Kolb-List: Re: Seized 447 From: "lucien" [quote="possums(at)bellsouth.net"]At 07:59 PM 7/24/2007, you wrote: > Possum, Sir: > That problem was with the weld on the recoil starter, not with the fan... my little > "overheat" was gummed up rings during the 447 Nazi Carbon Festival, > > (same engine though.... gotta love them there 447's... real character builders) > They are "character builders" that's for sure. Mine used to hunt like a bird dog any where under 5400 rpm. It was the old point ignition system though. It is amazing to me what a difference a dual carb 503 made in my life. I don't know if it's because of the two carburetors or just because it's a bigger engine (the extra 10 hp come in handy too). Still set up like it cam out of the box. Mine just stays put unless you pull the nose up or down, of course. Have 738 hours now - and I know it needs a rebuild, but I think it'll make it to 800 hours - then I'll throw it away and buy a new one. I can still get'um wholesale, so it's worth it just for the new muffler and shiny carbs. > [b] FWIW, the 503 gives the wandering midrange RPM too when it's configured with a single carb.... it may be slightly better with the 503, but it'll still give you fits. I was never able to cure it on my early 503 that had a single carb. Sure agree about the dual carbs, though, when I finally got my dual carb motor it was rock steady... heaven.... I loved my 447, though the single ignition had me even more attentive about those landing spots ;) LS -------- LS FS II Read this topic online here: http://forums.matronics.com/viewtopic.php?p=125596#125596 ________________________________ Message 23 ____________________________________ Time: 07:13:15 PM PST US Subject: Kolb-List: Fuel Efficiency ? was Re: Small Cross Country From: "lucien" Eugene Zimmerman wrote: > Mike, > > Cool Pict ! :-) > > > Your 15.27 mpg works out to a fuel burn of - > 4.25 gal. per hr. @ 65 mph > 3.9 gal. per hr. @ 60 mph > 3.6 gal. per hr. @ 55 mph > > Does this sound about right with your experience? > > I'm interested in finding out what others are experiencing in fuel > efficiency. > My stats: FS II 98' model 503 DCDI 2v, 3.47:1 C box w/clutch Warp drive 68" 3 blade empty weight 440lbs. Fuel burn at sea level at about 60mph was around 3gph. At my new altitude of 7000', it's slightly less than that just eyeballing it. Probably around 2.8gph... LS -------- LS FS II Read this topic online here: http://forums.matronics.com/viewtopic.php?p=125597#125597 ________________________________ Message 24 ____________________________________ Time: 07:59:13 PM PST US From: Eugene Zimmerman Subject: Re: Kolb-List: Fuel Efficiency ? was Re: Small Cross Country Jack, Thanks for sharing your fuel efficiency data. Your fuel burn is very close to what I have been able achieve. Your ground speed comes out to approximately 53.3 mph. Each aircraft has a specific airspeed at which it flies most efficient. To maximize fuel efficiency the engine's maximum fuel efficiency must coincide with the aircraft's most efficient air speed. The most efficient airspeed for my modified Firestar II is slightly less than 50 mph and varies slightly with air temperature and fuel load. I burn 2 gal. per hr. at 50 mph cruise @ 4000 rpm. My engine is a Rotax 618 which has the variable exhaust valves and is turning a 72" IVO in-flight adjustable prop at maximum pitch. In this configuration my plane and engine are quietly loafing along, but @ 6600 rpm full throttle the 618 is a thirsty beast and according to my fuel flow gauge, can drink over 8 gal. per hr. Gene On Jul 24, 2007, at 8:46 PM, Jack B. Hart wrote: > > > At 09:14 PM 7/23/07 -0400, you wrote: >> > >> I'm interested in finding out what others are experiencing in fuel >> efficiency. > > Eugene, > > I have a FireFly with a Simonini Victor 1+ mounted. I had never > taken any > data above 5,600 rpm because it is uncomfortable to cruise at any > rpm higher > than that. I have not been able to achieve the Simonini published > fuel flow > rates at 5,600 or lower. You can see my efforts to lean the engine > out on > the bottom of: > > http://www.thirdshift.com/jack/firefly/firefly121.html > > Last Saturday morning was my EAA Chapter 373 meeting, and I was a > little > late getting off. For the first time, I let the engine cruise at > 6,000 rpm. > I climbed to 2,870 feet asl to reach 55 degree F air to be sure that > coolant temperatures would stay within specs. Ground to ground > flight time > was 54 minutes and total fuel burn was 1.90 gallons for an overall > fuel burn > of 2.11 gph. Distance between airports is 23 miles and assuming an > additional mile for pattern distance, the total distance traveled > was 48 > miles. This gives 25.3 mpg. 2.11 gph at 6,000 rpm agrees with > Simonini's > published data for the Victor 1+. > > I have two EGT probes mounted. The second is mounted down stream > from the > first by about six inches. When running the engine at 5,500 rpm > the down > stream EGT probe will normally run 100 degrees higher than the engine > mounted probe. This is pretty constant down to about 4,500 rpm. > But when I > cruised at 6,000 rpm the down stream probe read 400 degrees > higher. Now > that I have had time to think about it, I believe what happened is the > engine was running up on the pipe. I believe the engine is falling > off the > pipe tuning if it is run at 5,500 rpm. I will be making some more > runs at > 5,900, 5,800 etc. rpm to see what happens. If this is the case, I can > lengthen the pipe or inject water to try an get better fuel economy > at 5,500 > rpm. > > Several years ago, I took some ground data on the Rotax 447 while > injecting > water, and I found that it did reduce fuel flow. It would be > interesting to > try this while flying to see what happens. If you would like to > see this > data, it can be seen at: > > http://www.thirdshift.com/jack/firefly/firefly58c.html > > Always more to do. > > Jack B. Hart FF004 > Winchester, IN > > ________________________________ Message 25 ____________________________________ Time: 08:09:49 PM PST US From: Eugene Zimmerman Subject: Re: Kolb-List: Fuel Efficiency ? was Re: Small Cross Country Thanks lucien, That is very good fuel efficiency. Sounds like you have your engine and prop dialed in right. On Jul 24, 2007, at 10:13 PM, lucien wrote: > My stats: > FS II 98' model > 503 DCDI 2v, 3.47:1 C box w/clutch > Warp drive 68" 3 blade > > empty weight 440lbs. > > Fuel burn at sea level at about 60mph was around 3gph. At my new > altitude of 7000', it's slightly less than that just eyeballing it. > Probably around 2.8gph... > > LS ________________________________ Message 26 ____________________________________ Time: 09:34:05 PM PST US From: possums Subject: Re: Kolb-List: Re: Seized 447 At 10:09 PM 7/24/2007, you wrote: > > > (same engine though.... gotta love them there 447's... real > character builders) > > > > They are "character builders" that's for sure. > >FWIW, the 503 gives the wandering midrange RPM too when it's >configured with a single carb.... it may be slightly better with the >503, but it'll still give you fits. I was never able to cure it on >my early 503 that had a single carb. > >Sure agree about the dual carbs, though, when I finally got my dual >carb motor it was rock steady... heaven.... > > >LS Well ...there you go - that's the answer - put another carburetor on it and be done with it! See, it's not so hard when we put our heads together. Problem solved! And that's how we do it right here in the good ole USA. ------------------------------------------------------------------------------------- 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.