---------------------------------------------------------- Kolb-List Digest Archive --- Total Messages Posted Thu 12/30/10: 12 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:36 AM - Re: Kolb-List Digest: 12 Msgs - 12/29/10 (Ted Cowan) 2. 04:39 AM - Re: to Kolb/Jabiru guys... (ces308) 3. 05:24 AM - Re: Re: to Kolb/Jabiru guys... (John Hauck) 4. 08:35 AM - Re: Re: Sonex or GP VW (Rick Neilsen) 5. 10:57 AM - Re: Christmas Day flight (Eddie) 6. 11:35 AM - Re: Re: Sonex or GP VW (Jack B. Hart) 7. 12:01 PM - Re: Sonex or GP VW (Jimmy Young) 8. 12:55 PM - Direct drive Generac (mark.shimei) 9. 02:21 PM - Re: Re: Sonex or GP VW (Dana Hague) 10. 02:32 PM - Re: Direct drive Generac (Dana Hague) 11. 03:10 PM - Re: Re: Sonex or GP VW (Charlie England) 12. 04:16 PM - Re: Re: Sonex or GP VW (Jack B. Hart) ________________________________ Message 1 _____________________________________ Time: 03:36:01 AM PST US From: "Ted Cowan" Subject: Kolb-List: Re: Kolb-List Digest: 12 Msgs - 12/29/10 loss of power and squirting gas on the block on hirth 3503. replaced main jets to original larger jets, checked comp pressure, 150 psi each cylinder, changed spark plugs and removed badly stretched cht ring. engine ran good, right to max rpm. dont know for sure which one did it but it is done. I suspect the compression was being lost on front cyl. to the extent that it was being dragged and could not produce enough power after 3000 rpm. anyway, you can put those results in your mind next time you have a problem and think you lost the rings or whatever in your kolb. I know my old 447 had ice once and I thought I messed up a piston but it was just carb ice. hit the carb enricher and it bucked and coughed but cleared it. buddy said it sounded like hell from the ground but I think he was talking about my heart! anyway, thanks for listening. things might not be what they seem sometimes. ted cowan, SS 912UL zoom zoom ________________________________ Message 2 _____________________________________ Time: 04:39:21 AM PST US Subject: Kolb-List: Re: to Kolb/Jabiru guys... From: "ces308" Hi Everyone, I got her going yesterday with the new float needle valve and she seems to run good....taxiing out I thought it stumbled for a second and returned to the hangar to run it up again,but all sounded good, so up I went. I ended up taking the carb off to install the new needle and will remove if it has to be done again later on ( hopefully not) ! The pink one is the old one...black tip is the new......the video was part of the test flight yesterday... Happy new year to all and have a safe weekend ! http://www.youtube.com/watch?v=r5fLA9byUdQ Read this topic online here: http://forums.matronics.com/viewtopic.php?p=324999#324999 Attachments: http://forums.matronics.com//files/takeoff_1_982x654_130.jpg http://forums.matronics.com//files/img_1610_1024x768_438.jpg ________________________________ Message 3 _____________________________________ Time: 05:24:32 AM PST US From: "John Hauck" Subject: Re: Kolb-List: Re: to Kolb/Jabiru guys... Happy new year to all and have a safe weekend ! http://www.youtube.com/watch?v=r5fLA9byUdQ Morning Folks: Glad you got your engine problem corrected. The Jabiru sounded good. Don't you have a two blade prop? I like the sound of a two blade prop. People used to tell me my Firestar with 447 and wooden two blade prop sounded almost like a "real airplane." You were getting a little frisky on the throttle during taxi after landing. ;-) You are flying out of Houghton Lake State? Landed there in 2003, on the way to Gaylord, home of my Army helicopter Instructor Pilot who soloed me in 1968. Then on to St Ignace to meet John Williamson and fly up to Sault Saint Marie and west along the south shore of Lake Superior. Eventually, we wound up at Scott Trask's in Iron Mountain, MI, where we met Rick Neilsen and Bill (has a FS), before we all flew down to Oshkosh. If I remember correctly, Houghton was grass. Longing to get some decent weather and get back on the cross country trail again soon. john h mkIII Titus, Alabama ________________________________ Message 4 _____________________________________ Time: 08:35:49 AM PST US Subject: Re: Kolb-List: Re: Sonex or GP VW From: Rick Neilsen Charlie/All Ok.... Lets just assume for a moment that the Generac will handle the harmonic, gyroscopic, and thrust loads. The engine is designed as a industrial engine which is a good thing except for weight and power. Valley Engineering souped up the Generac engine, lightened it a bit, added their reduction drive and put it on Jimmy Young's Kolb FS. Jimmy even had to opportunity to fly the plane with the engine installed and choose the best prop by flying a selection of props. With all that it was found to be inadequate for Jimmy. Imagine now that a stock Generac with a dirict drive prop is installed on what George feels is a much lighter FS. Lets also assume that George will get the prop selection perfect and will get conservatively as much as 80% of the thrust of a reduction drive Generec. Jimmy or anyone how well would the plane fly? I'm not a engineer and I could be way off base. I was only able to get maybe 60-70% of the reduction drive thrust from my direct drive VW engine. I can't find the rated RPM for the 32-33 HP Generac. Lower RPMs closer to 2000-2200 RPM would make for a better direct drive engine. RPMs in the 3200-3600 range like a VW make much better reduction drive engines. Again worth what you paid for it. Rick Neilsen Redrive VW Powered MKIIIC On Wed, Dec 29, 2010 at 10:33 PM, Charlie England wrote: > One of the Generac's attractions for me is that it's designed from the > start as an industrial, run all day at rated power, almost any kind of load > type of engine. While the power pulses are uneven & may give a reduction > drive fits, the engine & in particular the crank should handle almost > anything short of a serious resonance issue. VW & other auto engines were > never designed to take side loads on the end of the crank, but the Generac > crank has a pulley mounted to it in many applications (exception would be > direct drive generators). > > I could be wrong, but I would think that a wood prop on a direct drive > Generac would present less load than the crank sees while driving 4 feet of > steel blades through ant hills, small logs, etc with the load transferred to > the crank through a cantilevered pulley. > > FWIW, > > Charlie > > On 12/29/2010 10:06 AM, Rick Neilsen wrote: > > George > > I don't think the direct drive Generac option is a good choice for at least > two reasons. First, it doesn't sound like you will be happy with the > performance if it will even fly. > > ________________________________ Message 5 _____________________________________ Time: 10:57:28 AM PST US From: "Eddie" Subject: Re: Kolb-List: Christmas Day flight Thanks Pat It Looks ok in the photos but in reality with its first flight being april 1995 she is showing her age a bit when you get close . I spend a fair bit of time each year chasing rust away from the cage tubes and also as I bought her part repaired after an engine out on landing here at ince some of the fabric is more patches than fabric . That said she flies well and with two up and full fuel I often see in excess of 800 fpm on the vario . and If just pottering about locally can use as little as 12/13 litres an hour. I would love to recover the whole thing and powder coat the metal work but as I am just really getting comfortable flying her now after owning / repairing for about four years I dont want to take her out of the air untill my inspector says I have to. HAve a good new year yourself if I can get day a pass from she who must be obeyed I am going to try and fly new years day .It depends on the airfield , Ince can get very waterlogged and after all the snow it will probably be about a foot deep outside my hanger/trailer I will just have to keep my fingers crossed . Happy new year to all on the list and looking forward to another years kolbing in the Uk Eddie mk 111 c rotax 582 arplast 3blade Do not archive ________________________________ Message 6 _____________________________________ Time: 11:35:31 AM PST US From: "Jack B. Hart" Subject: Re: Kolb-List: Re: Sonex or GP VW From: Rick Neilsen Charlie/All > .............. Lets also assume that George will get the prop selection perfect and will get conservatively as much as 80% of the thrust of a reduction drive Generec. Jimmy or anyone how well would the plane fly? ............... > Rick/All Propeller selection can be a pain too. On the FireFly with the MZ34 mounted, I have run two different IVO propellers. Both have been cut to about the same radius. Med pitch 50" prop @ 14.0 deg - 5,500 rpm -> 23.0 hp @ 55 mphi Low pitch 54" prop @ 8.25 deg - 5,800 rpm -> 24.8 hp @ 40 mphi Low pitch 52" prop @ 8.25 deg - 6,000 rpm -> 26.0 hp @ 40 mphi This indicates to me that the low pitch IVO is not a very efficient propeller for the MZ34/FireFly combination. It is beating the air like crazy, but it is not passing enough air through the propeller arc to produce thrust at speed. I have cut the medium pitch IVO down to the limit, and with it set to minimum pitch, I can not get the engine up to speed. Called Compact Engines and they do not offer a larger ratio than 2.34 to 1. Called a propeller fellow and he said he could make a propeller that would do the job for $700+. Thought about it some more and decided to re-work the propeller hub and sheave combination to get a 2.60 to one reduction. I figure this ratio may do the trick. If not, I will go back to the propeller carvers. As it flew very well with the medium IVO, I could have left it the way it was, but there is something about leaving the last four horses in the barn. Should receive the new sheave next week. Jack B. Hart FF004 Winchester, IN ________________________________ Message 7 _____________________________________ Time: 12:01:51 PM PST US Subject: Kolb-List: Re: Sonex or GP VW From: "Jimmy Young" > Valley Engineering souped up the Generac engine,lightened it a bit, added their reduction driveand put it on Jimmy Young's Kolb FS. Jimmyeven had to opportunity to fly the plane with the engine installed and choose the best prop by flying a selection of props. With all that it was found to be inadequate for Jimmy. Imagine now that a stock Generac with a dirict drive prop is installed on what George feels is a much lighter FS. Lets also assume that George will get the prop selection perfect and will get conservatively as much as 80% of the thrust of a reduction drive Generec. Jimmy or anyone how well would the plane fly? George/Rick/All; Here's the way I see it. The Generac (Valley Engineering's version) needs to turn 3600 rpm to develop what was supposedly 38-40 hp. It didn't have enough power to safely fly my FS after 112 hrs of test flying with 4 different props. With the adjustable 72" 3 blade IVO, I pitched it so I was turning over 3800 rpm S&L flight and it was still a dog. It was ok on cool, still, stable early morning air, but heck I fly all the time in all kinds of air and it could not safely cut it at mid-day taking off with a crosswind and 95 degree humid air. It may fly someone else's plane that is much lighter or in a tractor config, but not my 435 lb dry & empty FS, and @ 750 lbs full fuel/me/& 20 lbs of baggage. I now have the 60 hp @ 6200 rpm HKS. Based on that, I should get 50% better performance with it over the Generac. It's more like 90% to 100% better. I'm not so sure the Generac ever developed 40 hp for me. Valley puts it on their tractor-pull 254 lb backyard flyer and apparently it works well for that plane. Tractor-pull aircraft are more efficient than our pusher-type Kolbs. They know more about the Generac & how to adapt it to aircraft than anyone around. I've done all the experimenting I care to do with aircraft engines and plan to stick only to a proven design from here on out. More power is more better, time tested proven designs trump what-ifs and how-abouts. Hoping you're going to make it over those trees on take off is not my idea of fun. I scraped the left side gear off my FS 2 years ago because I could not get enough climb taking off in a 90 deg. crosswind blowing over the hangars on a hot day. I aborted the take-off and made a perfect landing. As others have said before on this List, the only problem was I was 15 ft over the runway when I made it. Pilot error was the cause, not the engine, but it was a contributing factor. Do what you wish, but to go Generac-powered direct drive & a 56" prop in a FS could only be a worse scenario than what I tried, & I would highly discourage anyone from attempting it. -------- Jimmy Young Missouri City, TX Kolb FS II/HKS 700 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=325045#325045 ________________________________ Message 8 _____________________________________ Time: 12:55:36 PM PST US From: "mark.shimei" Subject: Kolb-List: Direct drive Generac I have been working on the direct drive Generac for over a year now...on and off. taking off the flywheel and installing a lighter part(made from the hub of the old flywheel) to hold the magnets/counterweight leaving the coils in place. Hub is mounted on the PTO end. May get it running in the next month or 2,trying to get the timing down. Engine will be installed on the Ultrastar which has the old Cuyuna....courtesy of Ted Cowan. ________________________________ Message 9 _____________________________________ Time: 02:21:07 PM PST US From: Dana Hague Subject: Re: Kolb-List: Re: Sonex or GP VW Jack, you give rpm at different speeds (level flight I presume). Did you measure the full throttle rate of climb at Vy for each prop? For ma y of us, that would be more meaningful than cruise performance. Rate of climb also directly proportional to power changes. -Dana At 02:27 PM 12/30/2010, Jack B. Hart wrote: >Propeller selection can be a pain too. On the FireFly with the MZ34 >mounted, I have run two different IVO propellers. Both have been cut to >about the same radius. > > Med pitch 50" prop @ 14.0 deg - 5,500 rpm -> 23.0 hp @ 55 mphi > Low pitch 54" prop @ 8.25 deg - 5,800 rpm -> 24.8 hp @ 40 mphi > Low pitch 52" prop @ 8.25 deg - 6,000 rpm -> 26.0 hp @ 40 mphi > >This indicates to me that the low pitch IVO is not a very efficient >propeller... -- HAL 9000: Dave. Put down those Windows disks, Dave. DAVE! ________________________________ Message 10 ____________________________________ Time: 02:32:48 PM PST US From: Dana Hague Subject: Re: Kolb-List: Direct drive Generac At 03:53 PM 12/30/2010, mark.shimei wrote: > >I have been working on the direct drive Generac.. > Engine will be installed on the Ultrastar which has the old > Cuyuna....courtesy of Ted Cowan. I'm looking forward to hearing about your results. I have the Cuyuna on my US now, but my friend complains it's too loud so he's giving me a fresh rebuilt 447 (he replaced it with a HKS on his GT400) while will probably go on my plane this winter. I'm looking forward to a significant takeoff and climb improvement... -Dana -- Illegal aliens have always been a problem in the United States. Ask any Indian. ________________________________ Message 11 ____________________________________ Time: 03:10:13 PM PST US From: Charlie England Subject: Re: Kolb-List: Re: Sonex or GP VW Hi Rick, Most industrial engines have a design rpm of 3600 (works for 60hz generator). A friend has built up a direct drive 992cc Generac & IIRC, the all up weight is a little under 80 lbs. That would mean about the same pwr/wt ratio as a traditional 4 stroke a/c engine. I wholeheartedly agree that 32-36hp is woefully inadequate for a 700+ lb, very high drag airframe, reduction drive or not. A long, paved strip might make it doable, but not much fun. I'd also agree that prop rpm lower than 3200-3600 would be much better for a high drag, low speed airframe, but I don't see any need to go as low as 2200rpm unless there's room to swing a 6.5-7 foot diameter prop, like the Valley guys are doing on their psru engines. Regular a/c engines swing 72"-74" diameter props at 2700 rpm with excellent efficiency. For efficiency, tip speed is tip speed (determined by diameter & rpm+minor addition for airspeed), & the variable for higher/lower hp is blade area. A lighter, lower drag airframe is a different story. The Europeans are flying several different designs with decent performance on 20+ hp industrial engines that aren't any lighter than the 36hp Generac. I think that you're absolutely correct in the context of underpowering particular airframes, but don't see a valid reason for a general dismissal of the industrial engines. Congrats on your successful VW install. Having had my share of grief with a direct drive VW, I'm glad to see VW's running successfully with reduction drives. Charlie On 12/30/2010 10:32 AM, Rick Neilsen wrote: > Charlie/All > Ok.... Lets just assume for a moment that the Generac will handle the > harmonic, gyroscopic, and thrust loads. The engine is designed as a > industrial engine which is a good thing except for weight and power. > Valley Engineering souped up the Generac engine, lightened it a bit, > added their reduction drive and put it on Jimmy Young's Kolb FS. > Jimmy even had to opportunity to fly the plane with the engine > installed and choose the best prop by flying a selection of props. > With all that it was found to be inadequate for Jimmy. Imagine now > that a stock Generac with a dirict drive prop is installed on what > George feels is a much lighter FS. Lets also assume that George will > get the prop selection perfect and will get conservatively as much as > 80% of the thrust of a reduction drive Generec. Jimmy or anyone how > well would the plane fly? > I'm not a engineer and I could be way off base. I was only able to get > maybe 60-70% of the reduction drive thrust from my direct drive VW engine. > I can't find the rated RPM for the 32-33 HP Generac. Lower RPMs > closer to 2000-2200 RPM would make for a better direct drive engine. > RPMs in the 3200-3600 range like a VW make much better reduction drive > engines. > Again worth what you paid for it. > Rick Neilsen > Redrive VW Powered MKIIIC > > On Wed, Dec 29, 2010 at 10:33 PM, Charlie England > > wrote: > > One of the Generac's attractions for me is that it's designed from > the start as an industrial, run all day at rated power, almost > any kind of load type of engine. While the power pulses are uneven > & may give a reduction drive fits, the engine & in particular the > crank should handle almost anything short of a serious resonance > issue. VW & other auto engines were never designed to take side > loads on the end of the crank, but the Generac crank has a pulley > mounted to it in many applications (exception would be direct > drive generators). > > I could be wrong, but I would think that a wood prop on a direct > drive Generac would present less load than the crank sees while > driving 4 feet of steel blades through ant hills, small logs, etc > with the load transferred to the crank through a cantilevered pulley. > > FWIW, > > Charlie > > On 12/29/2010 10:06 AM, Rick Neilsen wrote: >> George >> I don't think the direct drive Generac option is a good choice >> for at least two reasons. First, it doesn't sound like you will >> be happy with the performance if it will even fly. > > ________________________________ Message 12 ____________________________________ Time: 04:16:15 PM PST US From: "Jack B. Hart" Subject: Re: Kolb-List: Re: Sonex or GP VW From: Dana Hague > Jack, you give rpm at different speeds (level flight I presume). Did you measure the full throttle rate of climb at Vy for each prop? For many of us, that would be more meaningful than cruise performance. Rate of climb also directly proportional to power changes. > Dana, An amended data table follows: Climb Rate of Speed Climb Med pitch 50" @ 14.0 deg - 5,500 rpm -> 23.0 hp @ 55 mphi 45 mphi 300 fpm Low pitch 54" @ 8.25 deg - 5,800 rpm -> 24.8 hp @ 40 mphi 40 mphi ??? Low pitch 52" @ 8.25 deg - 6,000 rpm -> 26.0 hp @ 40 mphi 40 mphi ??? The low pitch propeller flights were very short and the engine speed did not vary until the FireFly was once again over the runway. Jack B. Hart FF004 Winchester, IN ------------------------------------------------------------------------------------- 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.