---------------------------------------------------------- Kitfox-List Digest Archive --- Total Messages Posted Sun 05/01/05:25 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:17 AM - Droop tips (kitfox@gto.net) 2. 05:50 AM - Re: Droop tips (kirk hull) 3. 09:15 AM - Re: Droop tips (kitfox@gto.net) 4. 10:41 AM - Re: Model V/VI successful groundloop? (Raystuff7@aol.com) 5. 11:12 AM - Re: Grove gear failure (Raystuff7@aol.com) 6. 11:12 AM - Re: Droop tips (Bruce Harrington) 7. 11:27 AM - [Kitfox off-topic] Rotax 582 question (Michel Verheughe) 8. 12:44 PM - Re: [Kitfox off-topic] Rotax 582 question (Cudnohufsky's) 9. 01:01 PM - Re: Grove gear failure (Cudnohufsky's) 10. 03:08 PM - Re: Droop tips (Chenoweth) 11. 03:16 PM - Re: [Kitfox off-topic] Rotax 582 question (Jim's Shaw Mail) 12. 03:26 PM - Re: CHT Probe Follow up (Donna and Roger McConnell) 13. 03:56 PM - [Kitfox off-topic] Rotax 582 question (kitfox@gto.net) 14. 04:15 PM - Re: Hard Landing, was brakes (Lowell Fitt) 15. 04:19 PM - Re: Spar protection (Lowell Fitt) 16. 05:10 PM - Re: [Kitfox off-topic] Rotax 582 question (Bob Robertson) 17. 05:48 PM - Is lugging the engine bad? (Randy Daughenbaugh) 18. 05:57 PM - Re: Is lugging the engine bad? (AlbertaIV@aol.com) 19. 06:09 PM - Re: Rotax 582 electric starter (Jim Burke) 20. 06:27 PM - Re: wheels and tires (Allan Aaron) 21. 07:47 PM - Re: Is lugging the engine bad? (kirk hull) 22. 08:05 PM - Re: Is lugging the engine bad? (Bob Robertson) 23. 08:34 PM - Re: Droop tips (kurt schrader) 24. 09:39 PM - Re: Is lugging the engine bad? (Alan Daniels) 25. 11:50 PM - Official Usage Guideline [Please Read] [Monthly Posting] (dralle@matronics.com) ________________________________ Message 1 _____________________________________ Time: 04:17:00 AM PST US Subject: Kitfox-List: Droop tips From: kitfox@gto.net --> Kitfox-List message posted by: kitfox@gto.net Ok guys good question for you all. What exactly do the droop tips do? What are the pros and cons of them ? Are they helpful in lift ? slow flight ? Are they drag in cruise ? Kirby Clint thanks > --> Kitfox-List message posted by: "Clint Bazzill" > > MY Book says that the Model IV-1050 the last serial no was 1722 > > Clint ________________________________ Message 2 _____________________________________ Time: 05:50:25 AM PST US From: "kirk hull" Subject: RE: Kitfox-List: Droop tips --> Kitfox-List message posted by: "kirk hull" What exactly do the droop tips do? add lift by stoping the high pressure air from the bottom of the wing from spilling around the end of the wing to the top. Often used with fences on top of the wing. What are the pros and cons of them ? They are Ugly and they impair visibility Are they helpful in lift ? slow flight ? Yes. Yes. Are they drag in cruise ? In most cases Yes. -----Original Message----- From: owner-kitfox-list-server@matronics.com [mailto:owner-kitfox-list-server@matronics.com]On Behalf Of kitfox@gto.net Subject: Kitfox-List: Droop tips --> Kitfox-List message posted by: kitfox@gto.net Ok guys good question for you all. What exactly do the droop tips do? What are the pros and cons of them ? Are they helpful in lift ? slow flight ? Are they drag in cruise ? Kirby Clint thanks > --> Kitfox-List message posted by: "Clint Bazzill" > > MY Book says that the Model IV-1050 the last serial no was 1722 > > Clint ________________________________ Message 3 _____________________________________ Time: 09:15:52 AM PST US Subject: RE: Kitfox-List: Droop tips From: kitfox@gto.net --> Kitfox-List message posted by: kitfox@gto.net Art I have the 1" strut fairings and the Tube gear fairings. I run 90 to 95 mph ias at 5800 to 6000 rpm so crusie not too bad. I feel that some more fairings would help give a few more mph possibly. There is a big gap between the tail and the horiontal stab.-- should this be covered up ? The Droop tips I not sure about removing as the short field performance is very good. Has anyone removed the droop tips ? And if so what was gained and lost? As far as ugly, I don't think they are that bad. Only thing they obstuct is a your attitude to the horizon. I do use the cross brace on the jury struts to give me a in relation to the horizon angle. When vertical, the droop tips make you look like you about to go inverted with that slant tip of the droop tip. Also my pitot tube, should it be level in levle flight? Mine is pointed up maybe 10 deg. or so. Kirby From: "kirk hull" Subject: RE: Kitfox-List: Droop tips > --> Kitfox-List message posted by: "kirk hull" > > > What exactly do the droop tips do? add lift by stoping the high pressure > air from the bottom of the wing from spilling > around the end of the wing to the top. Often used with fences on top of the > wing. > What are the pros and cons of them ? They are Ugly and they impair > visibility > > Are they helpful in lift ? slow flight ? Yes. Yes. > > Are they drag in cruise ? In most cases Yes ________________________________ Message 4 _____________________________________ Time: 10:41:07 AM PST US From: Raystuff7@aol.com Subject: Re: Kitfox-List: Model V/VI successful groundloop? --> Kitfox-List message posted by: Raystuff7@aol.com Robert, I have the aluminum gear legs. All my groundloops were on grass, fortunately. I never got a wing tip down. The Fox 6 has the CG about 11 1/2" aft the axles. The BD-4 has it about 9 1/2" aft. This arrangements makes for easy ground handling. When I turned the Fox gear legs around, it moves the axles 3" aft, and handles better on the ground and also makes it possible to do a good wheel landing. But the level weight on the tail went from 55 lbs to about 40 lbs. Even though the BD-4 is 500 lbs heavier, it had the same weight on the tail. I believe there is still enough weight on the tail to prevent nose-over with a careful pilot. One of the main reasons I was so concerned with this is my wife likes a tri-gear airplane, She learned to fly in a Cherokee. Anyway, I have just completed the conversion, and gone to the trigear on the Kitfox. I bought the nose gear assembly and just fiinished the job- it took a couple of week-ends. I havn't flown it , but taxied it around. I noticed a big difference in visibility over the nose, but it sure does seem to bounce around much more on the now shorter wheelbase. Ray Ward ________________________________ Message 5 _____________________________________ Time: 11:12:04 AM PST US From: Raystuff7@aol.com Subject: Re: Kitfox-List: Grove gear failure --> Kitfox-List message posted by: Raystuff7@aol.com Robert, Would be a big job to increase the diameter of the bolts. You might consider changing them to a higher grade bolt. I don't know what they are called, but they are of much higher tensile strength than regular AN bolts. BD-4's usually have the gear leg attachment points beefed up due to original design was a little weak. When asked, Jim Bede said, "Remember, if you beef up one point, then some other point will break. The landing gear is supposed to be destroyed in a crash; thus absobing some energy rather than the pilot's head". So be careful how you beef things up. Ray Ward ________________________________ Message 6 _____________________________________ Time: 11:12:38 AM PST US From: "Bruce Harrington" Subject: Re: Kitfox-List: Droop tips --> Kitfox-List message posted by: "Bruce Harrington" Hi Kirby, > The Droop tips I not sure about removing as the short field > performance is very good. > > Has anyone removed the droop tips ? And if so what was gained and > lost? I replaced mine with homemade non-droop tips. I didn't detect any significant difference in any flight characteristics. > Also my pitot tube, should it be level in levle flight? Mine is > pointed up maybe 10 deg. or so. > > Kirby bh ex-N194KF 582ed IV-1200, 800+ hrs ________________________________ Message 7 _____________________________________ Time: 11:27:43 AM PST US From: Michel Verheughe Subject: Kitfox-List: [Kitfox off-topic] Rotax 582 question --> Kitfox-List message posted by: Michel Verheughe On behalf of my hangar buddy, who has built an Asso VI microlight aircaft, with a used Rotax 582 and B gearbox, I have the following question: Why his engine can't get more than 5,300 RPM static? - The prop has been tested on another plane with 582 and it happily goes to 6,200 static. - His exhaust has been changed with my old exhaust, that worked very well. - His dual Bing carburettor has been changed with my old carburettor, that worked well on my engine. - He has installed a new fuel pump. - The cylinders have been measured and found to be round as they should. - The compression has been measured to 9 bars on both cylinders. - The three hours old spark plugs are light brown, as it should. - His tachometer has been calibrated with an optical one. - The engine is running nice ans smooth. But he can't exceed 5,300 RPM. He doesn't know what to do next, nor do I. Any idea, guys? Thanks in advance, Michel (PS: My Jabiru is going very well, thank you! :-) do not archive ________________________________ Message 8 _____________________________________ Time: 12:44:19 PM PST US From: "Cudnohufsky's" <7suds@chartermi.net> Subject: Re: Kitfox-List: [Kitfox off-topic] Rotax 582 question --> Kitfox-List message posted by: "Cudnohufsky's" <7suds@chartermi.net> Michel, Not an expert, but my experience with balancing engine RPM was with main jet size and prop pitch. Does the 582 run a rotary and / or reed valve intake? Lloyd ----- Original Message ----- From: "Michel Verheughe" Subject: Kitfox-List: [Kitfox off-topic] Rotax 582 question > --> Kitfox-List message posted by: Michel Verheughe > > On behalf of my hangar buddy, who has built an Asso VI microlight aircaft, > with > a used Rotax 582 and B gearbox, I have the following question: > Why his engine can't get more than 5,300 RPM static? > - The prop has been tested on another plane with 582 and it happily goes > to > 6,200 static. > - His exhaust has been changed with my old exhaust, that worked very well. > - His dual Bing carburettor has been changed with my old carburettor, that > worked well on my engine. > - He has installed a new fuel pump. > - The cylinders have been measured and found to be round as they should. > - The compression has been measured to 9 bars on both cylinders. > - The three hours old spark plugs are light brown, as it should. > - His tachometer has been calibrated with an optical one. > - The engine is running nice ans smooth. But he can't exceed 5,300 RPM. > > He doesn't know what to do next, nor do I. Any idea, guys? > > Thanks in advance, > > Michel > (PS: My Jabiru is going very well, thank you! :-) > > do not archive > > > ________________________________ Message 9 _____________________________________ Time: 01:01:02 PM PST US From: "Cudnohufsky's" <7suds@chartermi.net> Subject: Re: Kitfox-List: Grove gear failure --> Kitfox-List message posted by: "Cudnohufsky's" <7suds@chartermi.net> Robert, I am rebuilding a Model 5 that was damaged in a ground loop. It has the grove gear and it broke 2 landing gear bolts in the incident, fortunately the gear stayed attached but it still caused some structural damage in the area that I needed to repair, had the bolts not broken I an positive the damage to the fuselage would have been much more severe, possibly to the point that it may not have been worth repairing. All things have a weakest link, I guess I would rather have the gear break than rip the bottom tubes from the fuselage, my 2 cents worth. Lloyd ----- Original Message ----- From: "Harris, Robert" Subject: Kitfox-List: Grove gear failure > --> Kitfox-List message posted by: "Harris, Robert" > > > On a Kitfox V the bolts that attach the wheel to the Grove gear can break > when put under a side load, such as a ground loop. The end result is the > wheel will come off and the spring gear will bend. Apparently Grove is > aware > of this because when this information was told to the gal at Grove her > reply > was "Oh Yes." > > Can bigger bolts be used to attach the wheels to the Grove Gear? > > Robert > > > ________________________________ Message 10 ____________________________________ Time: 03:08:50 PM PST US From: "Chenoweth" Subject: Re: Kitfox-List: Droop tips --> Kitfox-List message posted by: "Chenoweth" Kirby, Well, one benefit I saw last year was that they provided a nice skid during a ground loop/runway excursion that a fellow I know made. Bill ----- Original Message ----- From: Subject: Kitfox-List: Droop tips > --> Kitfox-List message posted by: kitfox@gto.net > > Ok guys good question for you all. > What exactly do the droop tips do? > What are the pros and cons of them ? > Are they helpful in lift ? slow flight ? > Are they drag in cruise ? > > > Kirby > > > Clint thanks > > > --> Kitfox-List message posted by: "Clint Bazzill" > > > > > MY Book says that the Model IV-1050 the last serial no was 1722 > > > > Clint > > ________________________________ Message 11 ____________________________________ Time: 03:16:40 PM PST US From: "Jim's Shaw Mail" Subject: Re: Kitfox-List: [Kitfox off-topic] Rotax 582 question --> Kitfox-List message posted by: "Jim's Shaw Mail" Michel I suspect that the prop was tested on a "C" gear box with a 3:1 ratio and that the "B" gear box has a different ratio. A lot of B's had a 2.67 or so ratio. Jim Corner On May 1, 2005, at 12:27 PM, Michel Verheughe wrote: > --> Kitfox-List message posted by: Michel Verheughe > > On behalf of my hangar buddy, who has built an Asso VI microlight > aircaft, with > a used Rotax 582 and B gearbox, I have the following question: > Why his engine can't get more than 5,300 RPM static? > - The prop has been tested on another plane with 582 and it happily > goes to > 6,200 static. > - His exhaust has been changed with my old exhaust, that worked very > well. > - His dual Bing carburettor has been changed with my old carburettor, > that > worked well on my engine. > - He has installed a new fuel pump. > - The cylinders have been measured and found to be round as they > should. > - The compression has been measured to 9 bars on both cylinders. > - The three hours old spark plugs are light brown, as it should. > - His tachometer has been calibrated with an optical one. > - The engine is running nice ans smooth. But he can't exceed 5,300 RPM. > > He doesn't know what to do next, nor do I. Any idea, guys? > > Thanks in advance, > > Michel > (PS: My Jabiru is going very well, thank you! :-) > > do not archive > > ________________________________ Message 12 ____________________________________ Time: 03:26:39 PM PST US From: "Donna and Roger McConnell" Subject: RE: Kitfox-List: CHT Probe Follow up --> Kitfox-List message posted by: "Donna and Roger McConnell" Ok Guys and Gals, here is the straight scoop on sensors for those out there using the Quad Gage from Westach. First I'd like to thank John, Bob, Lowell and others who gave there input on this matter. As the FAA states, building your own airplane is suppose to be an education and I have truly learned a thing or two in the past few weeks. I called the people at Westach and they were very knowledgeable and helpful. I told them what I needed and what it was for and they agreed. But with the information that John McBean provided it was not hard to figure out. So for anyone with this type of setup, below are the four engine sensors you have to have to run on your Rotax engine. Mine are installed and it is a done deal. Westach Quad Gage 3AQ4KV Westach Temperature Sensor 399S10-1.5L -----------CHT 10x1.5 mm thrd 1" Tip Westach Temperature Sensor 399S10-1.5S ------------OT 10x1.5mm thrd 1/2" Tip Westach Thermocouple 712-2DWK -------------------EGT 48" Type K Westach Oil Pressure Transducer -------------------OP 387-100KV Happy Landings Roger Mac ________________________________ Message 13 ____________________________________ Time: 03:56:24 PM PST US Subject: Kitfox-List: [Kitfox off-topic] Rotax 582 question From: kitfox@gto.net --> Kitfox-List message posted by: kitfox@gto.net What prop and is pitch checked ? s/b 6200 static if box a B or C should not matter as RPM of engine should stilll be there. If plugs , carb and ehaust good --try making prop finer a degree or 2 Kirby > > - The prop has been tested on another plane with 582 and it happily goes > > to > > 6,200 static. ________________________________ Message 14 ____________________________________ Time: 04:15:48 PM PST US From: "Lowell Fitt" Subject: Re: Kitfox-List: Hard Landing, was brakes --> Kitfox-List message posted by: "Lowell Fitt" The thought I had on this was the limiting cables and the mention of a cracked seat pan. We had one hard landing reported to the list some time ago where the bulkhead was damaged by the limiting cables. I went to the spring gear for that reason. I know guys that don't have the limiting cables, also for that reason. Lowell ----- Original Message ----- From: Subject: Kitfox-List: Hard Landing, was brakes > --> Kitfox-List message posted by: AlbertaIV@aol.com > > > < I > did a go around and landed from the other direction with no problem. I > checked my tube gears with a manifying glass and there was not a sign of > a > crack.>> > > > This is not to promote or put down spring or tube gear. Your post did > trigger a thought in my mind. Under such an extreme hard landing (as you > describe) and it sounded very extreme, I'm "wondering" if more severe > testing > might be in order. A crack might not be detectable with visual means. I > know > it's a lot of work but if it were me, I'd "consider" doing some NDT/PT > testing on the gear and any other structural points. Didn't say I'd do > it but I > sure would feel better knowing. A hair line crack under the paint is > only > going to get worse until it breaks. Of course, that requires removing > some paint > and I don't know too many people that would be willing to do that. On > the > other hand, if it were a certified aircraft it might be required by the > FAA. > At some degree of a hard landing something is going to "BUST" whether > it > be tube/spring gear, mounting brackets, motor mounts, muffler, etc. > Again, this is not a gear issue but something that I wonder about. > > > Don Smythe > Classic IV w/ 582 > > > ________________________________ Message 15 ____________________________________ Time: 04:19:03 PM PST US From: "Lowell Fitt" Subject: Re: Kitfox-List: Spar protection --> Kitfox-List message posted by: "Lowell Fitt" My method was tying a ball of shearling lamb leather with wool in the middle of a length of cord and pulled it through the spars saturated with Zinc Cromate primer. I did it twice to get both sides of the stiffener. Lowell ----- Original Message ----- From: "Joel Mapes" Subject: Re: Kitfox-List: Spar protection > --> Kitfox-List message posted by: "Joel Mapes" > > > Our neighbors got a chuckle watching my wife and I corrosion proof the > interior of our spar tubes. We rinsed them with metal prep, sloshing and > rotating them while standing in the driveway. I used plastic wrap and > rubber > bands at first, but switched to tennis balls after finding the alodine > leaking around the plastic. After rinsing with water and drying we used > thinned zinc chromate epoxy primer, raising and lowering each end of the > wing while rotating it. The paint takes a long time to dry inside the > tubes > and the tennis balls just don't play like they used to. > > Joel > Model 5 912 GTA CS prop Aerocomp amphibs > > > ________________________________ Message 16 ____________________________________ Time: 05:10:21 PM PST US From: "Bob Robertson" Subject: Re: Kitfox-List: [Kitfox off-topic] Rotax 582 question --> Kitfox-List message posted by: "Bob Robertson" Michel, A bunch of the other have jumed in with some good ideas. It could be that the prop is set for a 3.00:1 gear drive. The B drive will have a 2.58 or a 2.20:1 reduction ratio. Double check the gear drive ratio as prop loading is the most common reason for lack or rpm. It could also be that the rotary valve is not installed correctly (if it was removed that is). We didn's see any/many of these in N.America, but there are TWO version of the 582. a 65 hp version AND a 48 hp version. He, by any chance, wouldn't have one of those would he? E-mail me the serial no. and I will check on the Rotax data base. regards Bob Robertson Light Engine Services Ltd. Rotax Service Center St. Albert, Ab. T8N 1M8 Ph: (Tech Support) 1-780-418-4164 Ph: (Order Line) 1-866-418-4164 (TOLL FREE) www.rtx-av-engines.ca ----- Original Message ----- From: "Michel Verheughe" Subject: Kitfox-List: [Kitfox off-topic] Rotax 582 question > --> Kitfox-List message posted by: Michel Verheughe > > On behalf of my hangar buddy, who has built an Asso VI microlight aircaft, with > a used Rotax 582 and B gearbox, I have the following question: > Why his engine can't get more than 5,300 RPM static? > - The prop has been tested on another plane with 582 and it happily goes to > 6,200 static. > - His exhaust has been changed with my old exhaust, that worked very well. > - His dual Bing carburettor has been changed with my old carburettor, that > worked well on my engine. > - He has installed a new fuel pump. > - The cylinders have been measured and found to be round as they should. > - The compression has been measured to 9 bars on both cylinders. > - The three hours old spark plugs are light brown, as it should. > - His tachometer has been calibrated with an optical one. > - The engine is running nice ans smooth. But he can't exceed 5,300 RPM. > > He doesn't know what to do next, nor do I. Any idea, guys? > > Thanks in advance, > > Michel > (PS: My Jabiru is going very well, thank you! :-) > > do not archive > > ________________________________ Message 17 ____________________________________ Time: 05:48:21 PM PST US From: "Randy Daughenbaugh" Subject: Kitfox-List: Is lugging the engine bad? --> Kitfox-List message posted by: "Randy Daughenbaugh" I have been trying to get a higher cruise speed by adding more pitch to my prop. For background, I have a Series 5 with Series 7 firewall forward (I think that for practical purposes, this makes it a Series 7 with 912S and a 72" Powerfin "F" prop. I have reached a point that gives me 5000 rpm at Wide Open Throttle on the ground. This only gives me a 108 mph cruise speed at 5500 rpm. I still get off the ground fast and climb at 900 fpm solo at 5000 ft. BUT, I have been told that it is hard on the engine to give it full throttle at 5000 rpm. That "lugging" the engine like this will hurt it. I am not too concerned since my strip is at 4400' and high manifold pressure at this altitude is still not too high. But will this hurt my engine? Is "lugging" with too much pitch in the prop bad? Randy - A CAP in my future? ________________________________ Message 18 ____________________________________ Time: 05:57:19 PM PST US From: AlbertaIV@aol.com Subject: Re: Kitfox-List: Is lugging the engine bad? --> Kitfox-List message posted by: AlbertaIV@aol.com In a message dated 5/1/2005 8:49:25 PM Eastern Standard Time, rjdaugh@rapidnet.com writes: But will this hurt my engine? Is "lugging" with too much pitch in the prop bad? Randy - A CAP in my future? Randy, I have heard that it is"NOT" good to "lug" a 582 by increasing the pitch to get more speed. However, I'm interested in hearing the responses on this subject. Don Smythe Classic IV w/ 582 ________________________________ Message 19 ____________________________________ Time: 06:09:05 PM PST US From: Jim Burke Subject: Kitfox-List: Re: Rotax 582 electric starter --> Kitfox-List message posted by: Jim Burke I would be interested in buying or trading for a good used or new Rotax 582 electric starter. Mine went down yesterday and I had to pull the engine today to change it out or repair it. I may just need to replace the brushes, but I haven't disassembled it yet. I plane on doing that tomorrow. James Burke Kitfox IV N94JE ________________________________ Message 20 ____________________________________ Time: 06:27:59 PM PST US Subject: RE: Kitfox-List: wheels and tires From: "Allan Aaron" --> Kitfox-List message posted by: "Allan Aaron" I have them on my avid speedwing with grove gear. Allan -----Original Message----- From: owner-kitfox-list-server@matronics.com [mailto:owner-kitfox-list-server@matronics.com] On Behalf Of customtrans@qwest.net Subject: Kitfox-List: wheels and tires --> Kitfox-List message posted by: customtrans@qwest.net Has anybody put 500X5 tires & wheels on the Kitfox? steve a ________________________________ Message 21 ____________________________________ Time: 07:47:24 PM PST US From: "kirk hull" Subject: RE: Kitfox-List: Is lugging the engine bad? --> Kitfox-List message posted by: "kirk hull" Yes it most deffinetly is. This will increase the forces on all of the internal parts and could push them beyond their designed limits and then to break. Immaging what the ultamite load ( a prop strike ) does to the insides of an engine. While the increased load is not nearly as high as a prop strike, It is extended over a long period of time giving the parts plenty of time to crack or bend -----Original Message----- From: owner-kitfox-list-server@matronics.com [mailto:owner-kitfox-list-server@matronics.com]On Behalf Of Randy Daughenbaugh Subject: Kitfox-List: Is lugging the engine bad? --> Kitfox-List message posted by: "Randy Daughenbaugh" I have been trying to get a higher cruise speed by adding more pitch to my prop. For background, I have a Series 5 with Series 7 firewall forward (I think that for practical purposes, this makes it a Series 7 with 912S and a 72" Powerfin "F" prop. I have reached a point that gives me 5000 rpm at Wide Open Throttle on the ground. This only gives me a 108 mph cruise speed at 5500 rpm. I still get off the ground fast and climb at 900 fpm solo at 5000 ft. BUT, I have been told that it is hard on the engine to give it full throttle at 5000 rpm. That "lugging" the engine like this will hurt it. I am not too concerned since my strip is at 4400' and high manifold pressure at this altitude is still not too high. But will this hurt my engine? Is "lugging" with too much pitch in the prop bad? Randy - A CAP in my future? ________________________________ Message 22 ____________________________________ Time: 08:05:51 PM PST US From: "Bob Robertson" Subject: Re: Kitfox-List: Is lugging the engine bad? --> Kitfox-List message posted by: "Bob Robertson" Hi Randy, A while ago I spoke with Eric Tucker of Kodiak Research re the 912 series of engines. His response to lowering the piston wear was to run the engine close to 5500 rpm at cruise. He related that this seems to be an ideal rpm to run this high compression engine. The design of your prop and the cleanliness of your airframe will have a lot to do with the max WOT rpm you can get. If you can only get 5500 rpm at WOT in level flight I would say that you are slightly over pitched. It would be better to back off the pitch a bit so you can get, say, 5700-5800 rpm max in level flight at WOT. You will be wasting a little fuel by drawing down the engine rpm with the prop. If your airframe is comparable to other series 7's and your weight is in line with other identical planes, I'd start looking at the design of the prop if you are not attaining the same level of performance as other similar planes.... You have to compare apples to apples here though.... just my two cents Bob Robertson Light Engine Services Ltd. Rotax Service Center St. Albert, Ab. T8N 1M8 Ph: (Tech Support) 1-780-418-4164 Ph: (Order Line) 1-866-418-4164 (TOLL FREE) www.rtx-av-engines.ca ----- Original Message ----- From: "Randy Daughenbaugh" Subject: Kitfox-List: Is lugging the engine bad? > --> Kitfox-List message posted by: "Randy Daughenbaugh" > > > I have been trying to get a higher cruise speed by adding more pitch to my > prop. For background, I have a Series 5 with Series 7 firewall forward (I > think that for practical purposes, this makes it a Series 7 with 912S and a > 72" Powerfin "F" prop. > > I have reached a point that gives me 5000 rpm at Wide Open Throttle on the > ground. This only gives me a 108 mph cruise speed at 5500 rpm. I still get > off the ground fast and climb at 900 fpm solo at 5000 ft. > > BUT, I have been told that it is hard on the engine to give it full throttle > at 5000 rpm. That "lugging" the engine like this will hurt it. I am not > too concerned since my strip is at 4400' and high manifold pressure at this > altitude is still not too high. > > But will this hurt my engine? Is "lugging" with too much pitch in the prop > bad? > > Randy - A CAP in my future? > > ________________________________ Message 23 ____________________________________ Time: 08:34:30 PM PST US From: kurt schrader Subject: RE: Kitfox-List: Droop tips --> Kitfox-List message posted by: kurt schrader Hi Kirby, Didn't see anyone answer you yet on the pitot tube question. Thought I would give an oppinion. I think the pitot tube should be somewhere between level and 7 degrees down. A little nose down gives you more accuracy during slow flight and stalls without sacrificing cruise accuracy. With yours nose up, you could be getting less accuracy during slow flight and stalls. 7 degrees down should split the difference between cruise and stall angles for best accuracy. Kurt S. --- kitfox@gto.net wrote: > ............. > Also my pitot tube, should it be level in levle > flight? Mine is pointed up maybe 10 deg. or so. > > > Kirby ________________________________ Message 24 ____________________________________ Time: 09:39:13 PM PST US From: Alan Daniels Subject: Re: Kitfox-List: Is lugging the engine bad? --> Kitfox-List message posted by: Alan Daniels I don't have any knowledge of engine wear, but if you set a 912s to get close to red line WOT level flight is a good compromise and works very well. I have tried several different pitches and that works well. Set that way I get 118 MPH in my 5/7 at 5500 rpm. It runs very easy at 5200 and reduces fuel consumption. The basic laws of engines says it takes fuel to make power. I don't have the exact number on the 912s but it is somewhere in the .5 pounds of fuel per hour per horsepower used. You can use simple math to figure out how much horsepower you are using in cruse. If you are using 4 GPH that is 24 pounds of fuel per hour. A half pound makes 1 horsepower so you are using about 48 horsepower if you are using 4 GPH. 5 GPH is 30 PPH or 60 HP. This can really help in setup by knowing your HP to speed. The biggest speed robber I have found is the flappron setting. You can check this by getting in normal cruise and checking your flap handle. If it has load on it - the handle wants to return to the full forward position- the trailing edge is too far down and needs adjusted. Even a little load can rob better than 5 MPH. You don't want to overdue it with reflex as the plane will mush when high and heavy. Some clever people put an extra detent in the system to give them just a little trailing down in those situations. One other note on rigging that I have found with the 7 FWF. All that I have flown have a left turning tendency, so I added an extra large diameter washer under the rubber isolator on he two on the left side to cant the engine a little to the right. I have done this on two planes now and it takes the left turn out of them. You have to do it before you fit the cowl to make it look right. Alan Bob Robertson wrote: >--> Kitfox-List message posted by: "Bob Robertson" > >Hi Randy, >A while ago I spoke with Eric Tucker of Kodiak Research re the 912 series of >engines. His response to lowering the piston wear was to run the engine >close to 5500 rpm at cruise. He related that this seems to be an ideal rpm >to run this high compression engine. >The design of your prop and the cleanliness of your airframe will have a lot >to do with the max WOT rpm you can get. >If you can only get 5500 rpm at WOT in level flight I would say that you are >slightly over pitched. It would be better to back off the pitch a bit so >you can get, say, 5700-5800 rpm max in level flight at WOT. >You will be wasting a little fuel by drawing down the engine rpm with the >prop. >If your airframe is comparable to other series 7's and your weight is in >line with other identical planes, I'd start looking at the design of the >prop if you are not attaining the same level of performance as other similar >planes.... You have to compare apples to apples here though.... > just my two cents > >Bob Robertson >Light Engine Services Ltd. >Rotax Service Center >St. Albert, Ab. T8N 1M8 >Ph: (Tech Support) 1-780-418-4164 >Ph: (Order Line) 1-866-418-4164 (TOLL FREE) >www.rtx-av-engines.ca > > >----- Original Message ----- >From: "Randy Daughenbaugh" >To: >Subject: Kitfox-List: Is lugging the engine bad? > > > > >>--> Kitfox-List message posted by: "Randy Daughenbaugh" >> >> > > > >>I have been trying to get a higher cruise speed by adding more pitch to my >>prop. For background, I have a Series 5 with Series 7 firewall forward >> >> >(I > > >>think that for practical purposes, this makes it a Series 7 with 912S and >> >> >a > > >>72" Powerfin "F" prop. >> >>I have reached a point that gives me 5000 rpm at Wide Open Throttle on the >>ground. This only gives me a 108 mph cruise speed at 5500 rpm. I still >> >> >get > > >>off the ground fast and climb at 900 fpm solo at 5000 ft. >> >>BUT, I have been told that it is hard on the engine to give it full >> >> >throttle > > >>at 5000 rpm. That "lugging" the engine like this will hurt it. I am not >>too concerned since my strip is at 4400' and high manifold pressure at >> >> >this > > >>altitude is still not too high. >> >>But will this hurt my engine? Is "lugging" with too much pitch in the >> >> >prop > > >>bad? >> >>Randy - A CAP in my future? >> >> >> >> > > > > ________________________________ Message 25 ____________________________________ Time: 11:50:47 PM PST US From: dralle@matronics.com Subject: Kitfox-List: Official Usage Guideline [Please Read] [Monthly Posting] DNA: do not archive --> Kitfox-List message posted by: dralle@matronics.com Dear Lister, Please read over the Kitfox-List Usage Guidelines below. The complete Kitfox-List FAQ including these Usage Guidelines can be found at the following URL: http://www.matronics.com/FAQs/Kitfox-List.FAQ.html Thank you, Matt Dralle Matronics Email List Administrator ****************************************************************************** Kitfox-List Usage Guidelines ****************************************************************************** The following details the official Usage Guidelines for the Kitfox-List. 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