---------------------------------------------------------- Kolb-List Digest Archive --- Total Messages Posted Fri 12/15/06: 14 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:56 AM - Re: engine replacement /Valley Big Twin (Monty Graves) 2. 05:47 AM - Re: Kolb Trailer Update (N27SB@aol.com) 3. 05:52 AM - Re: engine replacement /Valley Big Twin (John Hauck) 4. 06:05 AM - Re: engine replacement /Valley Big Twin (John Hauck) 5. 10:00 AM - Re: Overhaulin' (Ralph) 6. 10:18 AM - Re: Overhaulin' (David Lehman) 7. 12:14 PM - Re: engine replacement /Valley Big Twin (Richard & Martha Neilsen) 8. 12:27 PM - Re: engine replacement /Valley Big Twin () 9. 02:08 PM - Re: Hirth and Rotax a comparison (Richard Girard) 10. 02:27 PM - Re: engine replacement /Valley Big Twin (Richard & Martha Neilsen) 11. 03:30 PM - Re: For Dave (George Thompson) 12. 03:31 PM - Re: Hirth and Rotax a comparison (David Key) 13. 04:06 PM - Re: Hirth and Rotax a comparison (Jim Baker) 14. 04:43 PM - Re: For Dave (Bob Dalton) ________________________________ Message 1 _____________________________________ Time: 03:56:52 AM PST US From: Monty Graves Subject: Re: Kolb-List:engine replacement /Valley Big Twin speaking of engine replacements For those that may not have seen it yet. Valley Eng, of Rolla MO. has installed one their Big Twin 4 stroke industrial engines, featured in this months SPORT PILOT magazine, and seen at OSK. on a Kolb Twinstar. It is replacing single carb Rotax 503 on the Twinstar http://www.culverprops.com/big-twin.php I am not affiliated with the Smith's in any way, just passing some possible useful info along Monty ________________________________ Message 2 _____________________________________ Time: 05:47:40 AM PST US From: N27SB@aol.com Subject: Re: Kolb-List: Kolb Trailer Update Rick, If you glass the inside the stiffness will increase 5 fold. steve ________________________________ Message 3 _____________________________________ Time: 05:52:08 AM PST US From: "John Hauck" Subject: Re: Kolb-List:engine replacement /Valley Big Twin | | I am not affiliated with the Smith's in any way, just passing some possible | useful info along | Monty | Hi Monty: I find this quote from Valley Engineering a little hard to believe. This is in reference to the Kolb mkII and its test flight. "They were worried that the new location of the prop; 5"higher than it had been before would affect trim." I think Rick Nielsen would also question this. john h mkIII ________________________________ Message 4 _____________________________________ Time: 06:05:11 AM PST US From: "John Hauck" Subject: Re: Kolb-List:engine replacement /Valley Big Twin Hi Gang: Sorry about that. Had an incomplete quote in my previous post. Now it is fixed. john h | I find this quote from Valley Engineering a little hard to believe. | This is in reference to the Kolb mkII and its test flight. | | "They were worried that the new location of the prop; 5"higher than | it had been before would affect trim. The plane flew just like it did before the engine change " | | I think Rick Nielsen would also question this. | | john h | mkIII ________________________________ Message 5 _____________________________________ Time: 10:00:08 AM PST US From: "Ralph" Subject: Re: Kolb-List: Overhaulin' I have been running my 447 at 5000 RPM in cruise, 450 hours. The slower RPM should extend the TBO of the engine and so far it's working. I have peered through the exhaust ports and it looks very good. I'm using 50:1 synthetic Koltz oil and give it S*****m treatments (that's a dirty word here). I think I can get many more hours out of it. Ralph Original Firestar, 20 years flying it -- "Richard Pike" wrote: If you are lugging the engine, yes. If the engine is not being lugged, no. Jack Hart in his post on this subject gave an excellent analysis on the situation, as the crank load goes up expotentially as the rpm's increase, & the crank life is greatly extended by cruising at lower rpm's. That is why I am still in pursuit of streamlining & cleaning up the MKIII so that it becomes possible to attain acceptable cruise speeds at minimal 582 cruise rpm's. Right now I am able to cruise at 65-70 mph at around 5300 rpm's, and the bird is currently in the garage awaiting more streamlining so that it will (hopefully) become even more efficient. Don't know if I will accomplish anything or not, but the goal is to cruise at 65-70 at 5200 rpm or less. Not to mention that at this rpm the fuel burn is just slightly above 3 gph. And it is comparitively very quiet. Richard Pike MKIII N420P (420ldPoops) ----- Original Message ----- From: "John Hauck" Sent: Thursday, December 14, 2006 3:55 PM Subject: Re: Kolb-List: Overhaulin' > Isn't operational rpm a design factor? > > Running an engine too slow can be as harmful to it as over speeding. > > john h > mkIII > > > ________________________________________________________________________ ________________________________ Message 6 _____________________________________ Time: 10:18:34 AM PST US From: "David Lehman" Subject: Re: Kolb-List: Overhaulin' Ralph... What's your indicated airspeed at 5K RPM?... Does it feel like the airplane is "plowing" or "on the step" at that RPM... My original Firestar with a 503 feels more like it's "plowing" at that RPM and I think the indicated is around 50... At 5800 RPM, I indicate 60-63 mph, but I burn a lot of fuel... May be partly because of my draggy 850x6 tires... DVD On 12/15/06, Ralph wrote: > > > I have been running my 447 at 5000 RPM in cruise, 450 hours. The > slower RPM should extend the TBO of the engine and so far it's > working. I have peered through the exhaust ports and it looks very > good. I'm using 50:1 synthetic Koltz oil and give it S*****m > treatments (that's a dirty word here). I think I can get many more > hours out of it. > > Ralph > Original Firestar, 20 years flying it > > ________________________________ Message 7 _____________________________________ Time: 12:14:20 PM PST US From: "Richard & Martha Neilsen" Subject: Re: Kolb-List:engine replacement /Valley Big Twin Normally there is a big difference when the thrust line is moved up or down by 5 inches. I know this because I have done exactly that. In the case of the Valley Big twin it may not have had much effect. The Valley Big Twin would be a marginal engine in a MKII. Something like maybe a 503 in a MKII. A high thrust line problem is only a problem with lots of thrust. This engine may have also moved the CG of the MKII more aft. I would think the Valley Big Twin might make a good engine for a Firestar but again you want to be concerned with a high thrust line. I talked to these guys about the same redrive for my VW. They said that they tried it but it burned the belts and pulley. I have some concern with this type of harmonic dampening solution. My understanding is that the belts are allowed to slip in one direction. The problem is that wear on these parts could allow slippage in both directions. Now maybe you can detect the additional slippage and would start gradually if at all. Maybe you just replace the belts every 300 hours like you replace 2 stroke cranks. I just don't know. Time will tell. Definitely a discussion point for Gene Smith. In general I like the idea of this engine. Hey if you fly 2 strokes you are always flying on the edge of disaster anyway. Rick Neilsen Redrive VW powered MKIIIc ----- Original Message ----- From: "John Hauck" Sent: Friday, December 15, 2006 9:04 AM Subject: Re: Kolb-List:engine replacement /Valley Big Twin > > Hi Gang: > > Sorry about that. > > Had an incomplete quote in my previous post. Now it is fixed. > > john h > > > did before the engine change " > > > ________________________________ Message 8 _____________________________________ Time: 12:27:16 PM PST US From: Subject: Re: Kolb-List:engine replacement /Valley Big Twin > the Valley Big twin it may not have had much effect. The Valley Big Twin > would be a marginal engine in a MKII. Something like maybe a 503 in a MKII. I certainly don't pretend to have your engineering expertise, Rick, but I beg to differ on the 503 being marginal on the Mark II. Even on the hottest, highest DA days I get 600 fpm of climb. On a modest day, it's 800 and a good day is 1000. I can cruise all day at 5300 rpm giving 60 indicated and burning 3.2gph. I can also cruise at either 65 or 70 if I'm willing to burn a tad more juice. Please note that I'm flying every flight at gross weight because I'm a rather portly fellow who weighs in at 260. -Ken Fackler Kolb Mark II (under a Rotax 503) / A722KWF Rochester MI ________________________________ Message 9 _____________________________________ Time: 02:08:09 PM PST US From: "Richard Girard" Subject: Re: Kolb-List: Hirth and Rotax a comparison Anyone, anywhere, that has run a Hirth to TBO please step up and tell us about it. I'd love to have the confidence to buy that little flat twin of theirs for my motorglider, but the total package, i.e. fleet installs, repair data, parts availability, service information, and service availability, just doesn't stand up. I'm already into the A model of the MG, I think it unwise to add the engine into it, too. This 1000 hour TBO gets tossed around like it means something. No TBO means anything outside of advertising horse exhaust. If you don't make it, the warranty was most likely over long ago anyway so all you become for anyone is a data point of the real longevity of that engine. Rick On 12/15/06, Herb Gayheart wrote: > > > John > > I agree and would ask..are Rotax engines designed to run at 75% power > to achieve TBO? For instance, that would be abt 5100 RPMs for a DCDI > 503. Abt 39 hp.. The roughly equivalent Hirth is the 3702 which develops > 55 hp at 5500 rpms.. Its 75 % power is at 4100 rpms.. 41 hp. > Herb > > On Thu, 14 Dec 2006 14:55:53 -0600 "John Hauck" > writes: > > > > | The lower rpms of the Hirth engines might account for some of > > their > > | stated 1000 hour overhaul? Herb > > > > Herb: > > > > Isn't operational rpm a design factor? > > > > Running an engine too slow can be as harmful to it as over > > speeding. > > > > john h > > mkIII > > > > > > -- Rick Girard "Ya'll drop on in" takes on a whole new meaning when you live at the airport. ________________________________ Message 10 ____________________________________ Time: 02:27:27 PM PST US From: "Richard & Martha Neilsen" Subject: Re: Kolb-List:engine replacement /Valley Big Twin Ken Sorry but marginal is a rather subjective term. When I was flying my direct drive VW I didn't consider it marginal. I even flew a early MKIII with a 503 with over 400 lbs of passengers and it didn't seem marginal. Now get in a 80HP Rotax powered MKIII and you will understand. I'm sure the Johns will tell you a 80 Rotax is marginal. You have very respectable performance figures but once you fly one of the big kolbs with 80-100 redrive engine you will instantly recognize the transformation and you will agree your plane is marginal in Kolb or my terms. Also I really don't know the MKII that well and maybe it does better than I think it does with the 503. Also my "engineering expertise" ????? Fat dumb and happy is a better description. Do not archive Rick Neilsen Redrive VW powered MKIIIc ----- Original Message ----- From: Sent: Friday, December 15, 2006 3:24 PM Subject: Re: Kolb-List:engine replacement /Valley Big Twin > >> the Valley Big twin it may not have had much effect. The Valley Big Twin >> would be a marginal engine in a MKII. Something like maybe a 503 in a > MKII. > > I certainly don't pretend to have your engineering expertise, Rick, but I > beg to differ on the 503 being marginal on the Mark II. Even on the > hottest, > highest DA days I get 600 fpm of climb. On a modest day, it's 800 and a > good > day is 1000. I can cruise all day at 5300 rpm giving 60 indicated and > burning 3.2gph. I can also cruise at either 65 or 70 if I'm willing to > burn > a tad more juice. Please note that I'm flying every flight at gross weight > because I'm a rather portly fellow who weighs in at 260. > > -Ken Fackler > Kolb Mark II (under a Rotax 503) / A722KWF > Rochester MI > > > ________________________________ Message 11 ____________________________________ Time: 03:30:33 PM PST US From: "George Thompson" Subject: Re: Kolb-List: For Dave Sorry to be so late in getting back to you Bob. I think you will be pleased to know that your picture was featured on Dave's memorial program. Eve loved it and I thought it was a fantastic piece of photography. We all appreciate your work in putting it together. George----- Original Message ----- From: Bob Dalton To: kolb-list@matronics.com Sent: Wednesday, November 15, 2006 5:29 PM Subject: Kolb-List: For Dave All, I wanted to express a little more on the loss of Dave Pelletier and thought about putting together a slideshow. But I decided on this picture instead, it made me feel better. Bob D. ------------------------------------------------------------------------- ----- 11/16/2006 ________________________________ Message 12 ____________________________________ Time: 03:31:49 PM PST US From: "David Key" Subject: Re: Kolb-List: Hirth and Rotax a comparison I don't think you can compare the two engines. Who uses Hirths any more? ________________________________ Message 13 ____________________________________ Time: 04:06:11 PM PST US From: "Jim Baker" Subject: Re: Kolb-List: Hirth and Rotax a comparison X-mailer: Pegasus Mail for Windows (4.41) > > I don't think you can compare the two engines. Who uses Hirths any more? > I do...... Jim Baker 580.788.2779 Elmore City, OK ________________________________ Message 14 ____________________________________ Time: 04:43:02 PM PST US From: "Bob Dalton" Subject: RE: Kolb-List: For Dave George, Thank you for the kind words, I am happy that it was used at Dave's memorial. Give Eve a big hug for us all. Bob Dalton _____ From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of George Thompson Sent: Friday, December 15, 2006 3:30 PM Subject: Re: Kolb-List: For Dave Sorry to be so late in getting back to you Bob. I think you will be pleased to know that your picture was featured on Dave's memorial program. Eve loved it and I thought it was a fantastic piece of photography. We all appreciate your work in putting it together. George----- Original Message ----- From: Bob Dalton Sent: Wednesday, November 15, 2006 5:29 PM Subject: Kolb-List: For Dave All, I wanted to express a little more on the loss of Dave Pelletier and thought about putting together a slideshow. But I decided on this picture instead, it made me feel better. Bob D. _____ ------------------------------------------------------------------------------------- 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.