KR> VW mount evolution
In the old KR1 cutaway, it seems to show channel iron with rubber mounts against the firewall, and the back of the VW is mounted to that. Now it seems more traditional mounts are in use. I vaguely recall from 25 years ago reading that there was a reason for getting off that, but I don't recall what it is. Anyone have any info on that? -- next part -- A non-text attachment was scrubbed... Name: KR1 cutaway.JPG Type: image/jpeg Size: 109410 bytes Desc: not available URL: <http://list.krnet.org/mailman/private/krnet_list.krnet.org/attachments/20150202/09d91c05/attachment.JPG>
KR> ADS-B and homebuilts
Found this on FAA Q/A page: http://www.faa.gov/nextgen/programs/adsb/faq/#4 Will the ADS-B system be implemented as an enforcement tool to collect user fees, carbon offsets, tax assessments, or for FAA enforcement actions?The FAA has no plans to use ADS-B as an enforcement tool to collect fees, carbon offsets, or tax assessments. The FAA does need to ensure that ADS-B transmissions being broadcast from aircraft comply with the established performance and parameter-reporting requirements identified in the ADS-B Out rule in Title 14 CFR Part 91. The FAA Flight Standards office may take enforcement action to ensure aircraft comply with these regulations. Will the ADS-B system be implemented as an enforcement... for FAA enforcement actions? see? "no plans to use ADS-B as an enforcement tool to collect fees, carbon offsets, or tax assessments"
KR> Original RR three blade props
What ever happened to get those *nice looking* three blade props RR used to sell to be discontinued, and is there any similar replacement? I would really like a ground adj three blade prop like that. I read some mention in the newsletter archive that reported good performance with the prop. I vaguely recall there was an issue maybe with losing blades or something?
KR> Original RR three blade props
Reliability issues have driven the design to new and better configurations, both on the engine mount and the props. > On Feb 2, 2015, at 5:12 AM, Chris Prata via KRnet > wrote: > > What ever happened to get those *nice looking* three blade props RR used to > sell to be discontinued, and is there any similar replacement? I would really > like a ground adj three blade prop like that. I read some mention in the > newsletter archive that reported good performance with the prop. I vaguely > recall there was an issue maybe with losing blades or something? > > ___ > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org > please see other KRnet info at http://www.krnet.org/info.html > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change > options
KR> Original RR three blade props
Chris Prata wrote: >>What ever happened to get those *nice looking* three blade props RR used to sell to be discontinued, and is there any similar replacement? << The Newsletters detail the history (along with a lot of other useful information). Reports of thrown blades caused it's fall from glory. Warp Drive is the successor these days (and IVO, but their reputation is more dodgy). It is worth mentioning that many VW-based engine manufacturers discourage or forbid the use of heavy props such as these, due to crank loading issues. You can build you can own three-blade wooden prop, if you really want one. Add several more months to build time... Mark Langford, Harvest, AL ML at N56ML.com www.N56ML.com
KR> VW mount evolution
On 2/2/2015 5:24 AM, Chris Prata via KRnet wrote: > In the old KR1 cutaway, it seems to show channel iron with rubber mounts > against the firewall, and the back of the VW is mounted to that. Now it seems > more traditional mounts are in use. I vaguely recall from 25 years ago > reading that there was a reason for getting off that, but I don't recall what > it is. > Anyone have any info on that? > > It was Aluminum channel and put things too close to the firewall, Virg
KR> VW mount evolution
The current accessory case uses a traditional conical-mount layout, and thus works with a standard aircraft-style engine mount. I believe it is bolt-pattern-compatible with the O-200 & smaller Continentals... On 2/2/2015 6:04 AM, Virgil N.Salisbury via KRnet wrote: > On 2/2/2015 5:24 AM, Chris Prata via KRnet wrote: >> In the old KR1 cutaway, it seems to show channel iron with rubber >> mounts against the firewall, and the back of the VW is mounted to >> that. Now it seems more traditional mounts are in use. I vaguely >> recall from 25 years ago reading that there was a reason for getting >> off that, but I don't recall what it is. >> Anyone have any info on that? >> >> > It was Aluminum channel and put things too close to the firewall, > Virg > ___ > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org > please see other KRnet info at http://www.krnet.org/info.html > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to > change options
KR> Zenith Carb Installation
The Zenith carb model 14998 has been used on tens of thousands of farm tractors and industrial engines. Zenith carbs and repair parts and kits are only sold through retail dealers. Prices vary. The model 14998 is an updraft carb with a side draft air entrance. This carb will not function properly with negative g operations due to having a float bowl. The factory supplied float valve pin, idle jet seal and main jet seal will not tolerate ethanol fuels. 100LL and ethanol-free fuels work fine. There are aftermarket kits available that replace the seals with ethanol tolerant seals. I do not know what the rubber seal material is made of. The main jet is adjustable for mixture control, but tends to leak around the shaft if the gland nut is not securely tightened after the mixture is adjusted. With the gland nut tight, the mixture cannot be adjusted. The model 14998 is a good size match for the 2180 cc VW that I am using. I paid $286 for this carb from Great Plains Aircraft; the GP website now quotes $387. There are other carbs specifically made for aircraft operations; prices vary. Sid Wood Tri-gear KR-2 N6242 Mechanicsville, MD, USA -- Is that a side draft carb ? And for which engine ? Virg
KR> Zenith Carb Installation
Thank you Sid. I would be looking for a true side draft carb, Virg On 2/2/2015 11:00 AM, Sid Wood via KRnet wrote: > The Zenith carb model 14998 has been used on tens of thousands of farm > tractors and industrial engines. Zenith carbs and repair parts and > kits are only sold through retail dealers. Prices vary. The model > 14998 is an updraft carb with a side draft air entrance. > > > ___ > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org > please see other KRnet info at http://www.krnet.org/info.html > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to > change options >
KR> Steve(s)
Steve's original KR-1 had at least three different owners that I know of after he sold it (I was the first one) before being destroyed by the last one. Briefly, as I remember, he was fast taxiing, reportedly not realizing he was holding full aft stick, it suddenly leaped into the air to about 50 feet, he then over-corrected and hit the runway. I don't believe he was injured. I think he was about as unfamiliar with the KR as anyone could be. He even told me that he believed it had a "Rotax" engine in it. He reported that it was taken to another location off-airport by a friend, dismantled, and cut up - the pieces were "used in some other project" - who knows what. If you do an NTSB search, you may find a description of the incident - can't remember the year. A couple of the attached pictures shows Steve demonstrating "level flight" to a potential buyer. The last two pictures are of the airplane when I owned it. Ed Janssen From: Flesner via KRnet A quick check of the FAA registry indicates the airplane may still be alive and well in Arkansas. It's registration was just cancelled recently. If so it ought to go the EAA museum as one of the first KR's, built in 1977. Larry Flesner -- next part -- A non-text attachment was scrubbed... Name: N31123 before purchase.jpg Type: image/jpeg Size: 41562 bytes Desc: not available URL: <http://list.krnet.org/mailman/private/krnet_list.krnet.org/attachments/20150202/641b8032/attachment.jpg> -- next part -- A non-text attachment was scrubbed... Name: N31123.jpg Type: image/jpeg Size: 41537 bytes Desc: not available URL: <http://list.krnet.org/mailman/private/krnet_list.krnet.org/attachments/20150202/641b8032/attachment-0001.jpg>
KR> VW mount evolution
I wonder if the newer, larger engines (and a battery on the firewall) would solve this and *particularly* if there is any other problem with using the original mount method, other than balancing the CG? I like the look of the shorter nose. > From: ejanssen at ctiwireless.com > To: chrisprata at live.com > Subject: Re: KR> VW mount evolution > Date: Mon, 2 Feb 2015 08:59:08 -0600 > > The original KR-1 tended to be tail heavy, especially when the gear was > retracted, so, later, most builders after that went with a built up motor > mount. It also gave more room for a starter and working on the rear mounted > Slick magneto. >
KR> Original RR three blade props
Thanks Mark, I did spend some time and found some early 1980ish reports of the initial issues. Bummer. That prop was beautiful. The other issue is whather the *new* aftermarket forged alloy cranks with extra bearing support added to the crankcase would still not be good to hang a ground adjustable (or even in-flight adjustable) onto??? > To: krnet at list.krnet.org > Date: Mon, 2 Feb 2015 07:29:19 -0600 > Subject: Re: KR> Original RR three blade props > From: krnet at list.krnet.org > > Chris Prata wrote: > > >>What ever happened to get those *nice looking* three blade props RR used > to sell to be discontinued, and is there any similar replacement? << > > The Newsletters detail the history (along with a lot of other useful > information). Reports of thrown blades caused it's fall from glory. Warp > Drive is the successor these days (and IVO, but their reputation is more > dodgy). It is worth mentioning that many VW-based engine manufacturers > discourage or forbid the use of heavy props such as these, due to crank > loading issues. You can build you can own three-blade wooden prop, if you > really want one. Add several more months to build time... > > Mark Langford, Harvest, AL > ML at N56ML.com > www.N56ML.com > >
KR> Great Plains
Steve is not the youngest kid on the block anymore. An opportunity came along to sell Great Plains to Marty Roberts that was good for both of us. Linda and our son Scott will continue to do the landing gear, wheels, brakes, tires and tubes (OKeefeAero.com). Linda and I both have a desire to do a little sight seeing around the US with our F350 and 5th wheel, and the sale of Great Plains to Marty will allow us to do that. Marty is pretty well up and running. He has all the parts for direct drive engines and most of the parts for flywheel drive engines (not to be confused with rear drive where we had the housing and dampener). He only has to have some hubs made for the flywheel drive. He has all the individual engine parts, bearings, cases, heads, Force One Hub kits, dual ignition, etc... and of course the Diehl Accessory Case Components. All the parts that Linda and I carried - Marty has or will have them also. In October of 2014, we sold all of our Sonerai parts to Fred Keip. Fred has been the Sonerai Newsletter Editor for many years and has built and flown his Sonerai II for well over 1000 hours, VW powered of course. Fred has the same products that we sold for the Sonerai Family of aircraft, so it was a smooth transition also. Linda is updating the Great Plains catalog and it will be back on line in a couple of weeks. It was out of date - price wise and did not match the shopping cart prices. Linda and I are in the background, helping Marty and Ellen (Marty's wife) do as smooth of a transition as possible. Our goal was to transition the parts to individuals that would continue to support the homebuilt community. Too many times when a sport aircraft company is sold, the new owners fail and leaves many homebuilders without support of the product/s they purchased from the company. We did/do not want that to happen. Steve Bennett
KR> Great Plains
Good Luck Steve and Linda on your future adventures!?I'm sure I speak for?all of us here that have dealt with you in the past for VW parts etc. when I say that we appreciate the many years of excellent support that you both provided.?Happy Trails ! Enjoy your retirement!?RegardsChris GardinerC-GKRZ? On Monday, February 2, 2015 3:19 PM, STEVE via KRnet wrote: Steve is not the youngest kid on the block anymore.? An opportunity came along to sell Great Plains to Marty Roberts that was good for both of us.? Linda and our son Scott will continue to do the landing gear, wheels, brakes, tires and tubes (OKeefeAero.com).? Linda and I both have a desire to do a little sight seeing around the US with our F350 and 5th wheel, and the sale of Great Plains to Marty will allow us to do that. Marty is pretty well up and running.? He has all the parts for direct drive engines and most of the parts for flywheel drive engines (not to be confused with rear drive where we had the housing and dampener).? He only has to have some hubs made for the flywheel drive. He has all the individual engine parts, bearings, cases, heads, Force One Hub kits, dual ignition, etc... and of course the Diehl Accessory Case Components.? All the parts that Linda and I carried - Marty has or will have them also. In October of 2014, we sold all of our Sonerai parts to Fred Keip.? Fred has been the Sonerai Newsletter Editor for many years and has built and flown his Sonerai II for well over 1000 hours, VW powered of course. Fred has the same products that we sold for the Sonerai Family of aircraft, so it was a smooth transition also. Linda is updating the Great Plains catalog and it will be back on line in a couple of weeks.? It was out of date - price wise and did not match the shopping cart prices. Linda and I are in the background, helping Marty and Ellen (Marty's wife) do as smooth of a transition as possible. Our goal was to transition the parts to individuals that would continue to support the homebuilt community.? Too many times when a sport aircraft company is sold, the new owners fail and leaves many homebuilders without support of the product/s they purchased from the company.? We did/do not want that to happen. Steve Bennett ??? ??? ??? ? ??? ??? ? ___ Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org please see other KRnet info at http://www.krnet.org/info.html see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options
KR> Great Plains
Thank You Steve. K R Dinners, Gatherings and all that. ENJOY, Virg On 2/2/2015 3:18 PM, STEVE via KRnet wrote: > Steve is not the youngest kid on the block anymore. An opportunity came > along to sell Great Plains to Marty Roberts that was good for both of us. > Linda and our son Scott will continue to do the landing gear, wheels, brakes, > tires and tubes (OKeefeAero.com). Linda and I both have a desire to do a > little sight seeing around the US with our F350 and 5th wheel, and the sale > of Great Plains to Marty will allow us to do that. > > > > Steve Bennett > > > > > > > ___ > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org > please see other KRnet info at http://www.krnet.org/info.html > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change > options >
KR> Steve Bennett's KR-1 N31123
Thanks Larry for looking it up. Steve told me it had been wrecked by whoever he had sold it to. The following NTSB report indicates the accident was in April 1990 at Blytheville, Arkansas, apparently on an Eaker AFB runway. >From the NTSB: WHILE MAKING A FULL POWER GROUND RUN IN HIS NEWLY ACQUIRED TAIL WHEEL CONFIGURED HOMEBUILT AIRPLANE, WITH THE STICK IN THE FULL AFT POSITION, THE PILOT EXPERIENCED AN IMMEDIATE ABRUPT CLIMB TO ABOUT 50 FEET AGL. THE AIRPLANE THEN STALLED AND DESCENDED UNCONTROLLED TO THE TERRAIN. THIS WAS THE PILOT'S FIRST FLIGHT IN THE AIRPLANE AND GUSTY CROSSWIND CONDITIONS EXISTED. THE PILOT STATED THAT HE WAS CONCENTRATING ON DIRECTIONAL CONTROL WITH THE RUDDER, AND WAS NOT AWARE THAT THE STICK WAS FULL AFT. The National Transportation Safety Board determines the probable cause(s) of this accident as follows: IMPROPER HANDLING OF THE AIRCRAFT DURING A HIGH SPEED TAXI. My first KR (picture attached) was also wrecked in 1990 by the fellow I'd sold it to. It was a victim, as was Steve's, of yet another idiotic "high speed taxi text". He ran it off the end of a 4500 ft. runway at Rialto. I don't have enough words to describe just how stupid it is to run an aircraft, especially a taildragger, down a runway a high speed unless one is landing or taking off. Here's a link to the KR newsletter that has Steve's flight report on this plane. http://www.bouyea.net/newsletters/singlefiles/Issue045-Mar1979.pdf Mike KSEE Man, 63, Avoids Wrinkles 63 Yr Old Man Shares Simple DIY Skin Tightening Method He Uses At Home http://thirdpartyoffers.juno.com/TGL3141/54cff3585e6b473586704st04vuc -- next part -- A non-text attachment was scrubbed... Name: borrego.jpg Type: image/jpeg Size: 81531 bytes Desc: not available URL: <http://list.krnet.org/mailman/private/krnet_list.krnet.org/attachments/20150202/05169bf6/attachment.jpg>
KR> taxi testing
Mike Stirewalt wrote: > I don't have enough words to describe just how stupid it is to > run an aircraft, especially a taildragger, down a runway a high speed > unless one is landing or taking off. I think the stupid part was the full-aft stick and the gusty crosswinds during a high speed taxi in a plane known to be very sensitive to control inputs. I did about 75 high speed tail-up and -down taxi tests before my first flight, and credit it with giving me the confidence to successfully land it on my first flight. Your mileage must have varied. FYI, for those who have yet to fly a taildragger, one should not pull the stick BACK at full throttle unless the intention is to fly! Taxi tests should only involve FORWARD stick to get the tail up. Once there, it is hoped that it would give the pilot an indication of where the "neutral stick" location is. Any further aft should be reserved for flying, unless you are doing runups or slow-speed taxiing in high winds and want to keep the tail down... Mark Langford ML at N56ML.com http://www.n56ml.com
KR> Props
There's been mention lately of ground adjustable props. If you've got an O-200 a CS prop is the cat's meow but for VW.Revmaster-powered KR's I would suggest a variable pitch prop is completely unnecessary. My first KR had a Revmaster 2100 with the Maloof CS prop. The controller never did work very well so most converted (as I did) to a two-position switch which gave either full coarse or full fine pitch. It's been so long since I sold that plane that I can't remember if I found the ability to vary the pitch to be of any value - but it looked cool. The Maloof was most useful for those who flew high in turbocharged Revmasters. It was only on the turbocharged installations that the Maloof failures occured if I recall correctly. There were only one or two failures, but that was enough to doom the Maloof. I have three props for my current KR - Ken Cottle's KR-1?. When I bought it from Steve it had a Sterba 52 x 52 which would allow me to max out at full throttle in cruise at around 3600 RPM. I was going 170 MPH at that RPM and a lot of the old KR guys who liked to rebuild their engines frequently used to run around at that RPM, but engine temps are through the roof. For reasons of fuel economy and engine longevity I wanted to run full throttle (above 8000 ft.) at a more reasonable RPM. (Steve, BTW, used to cruise this plane at 2900 RPM with the 52 x 52, partial throttle). So I bought a Prince 52 x 54. This gave me a full throttle RPM of 3200 in cruise. I would have kept the Prince on the plane except going through quite a bit of rain on a trip to Mt. Vernon and Naples Florida and back home the leading edges of this prop pretty much dissolved. I ordered a Sterba 52 x 56 (Sterba has good urethane leading edges) which gives me a full throttle RPM of 3100-3200 in cruise above 8 thousand feet. I may get around to sending it back to Ed to put just a tad more pitch in it. 52 x 57 would be just perfect. I'd rather run the engine full throttle at 3000-3100 when cruising above 8000, instead of 3100-3200. I'm usually quite a bit higher than 8K, so the more pitch the better. I get 100 more RPM at 12K than I do at 8K. Why the emphasis on full throttle? Well, the throttle plate in the Ellison is fully open and the engine is breathing unrestricted. As an air pump the engine is at its most efficient when running with a completely open throttle. Below 8000' full throttle would develop more than 75% power with resultant high oil and cylinder head temps and poor economy. Above that altitude full throttle renders less than 75% so for this reason and the reduction in parasitic drag, and for any number of other reasons, up high is the place to be. Flying partial throttle above 8000' is inefficient. Except for takeoff, I really don't want to pull more than 75% power from my engine below 8000 feet. At altitude, 11.5 - 13.5, with my Sterba 52 x 56, I cruise an average of 149 MPH/3.5 GPH using around 50% power. Makes for a happy and long-lasting engine. With my 21 gallons I plan on 500 mile legs stretchable to 600 or 700. I have oxygen, which makes this sort of flying practical. Even down low and using partial throttle, I get more thrust per RPM - more efficiency - with a coarse prop. Engine temps (the VW killer) are dramatically lower with lower RPM. Friction losses (and resultant heat) are minimized. Unless you're based at a 1500' grass strip with obstructions at each end, there's not much reason to use the flat props I see many KR people using and there's no reason at all to use something that's ground adjustable. IMHO. The point of this little prop history is that whether I've got a 52 x 52 turning 3300+ on takeoff or a 52 x 56 turning 2900 on takeoff, my KR accelerates and leaves the ground quickly. The coarser prop is not turning as fast, but it's pushing more air with each revolution. When visiting friends I've taken off at Telluride with full tanks with the 52 x 56 and although I seldom frequent the short grass strips common in many other parts of the country, I've never been anywhere where I was concerned about taking off. Ken built my KR with the normal 20 ft. 8 in. wingspan and the same forces that make it want to float forever when landing are also at work in getting it off the ground. In my opinion there is no reason to consider the complexity, weight, and cost (not to mention the unreliability issues with some of the makers of those props) of a variable pitch prop for VW engines in a KR. Mike KSEE How Old Men Tighten Skin 63 Year Old Man Shares DIY Skin Tightening Method You Can Do From Home http://thirdpartyoffers.juno.com/TGL3141/54d00ed157f98ed133b9st03vuc -- next part -- A non-text attachment was scrubbed... Name: borrego.jpg Type: image/jpeg Size: 81531 bytes Desc: not
KR> aerolnjector
Hi everyone, Has anyone out there ever used any one of the aerocarb products on a 0-200? I don't know long this Aerolnjector carberator system has been out. If there is please let me know. I 'm thinking about contacting the company but didn't know if I was wasting my time. http://s449.photobucket.com/user/rkpsk1/library/
KR> Props
Thanks for some good info, Mike. I had suspected some of this and now you have put some hard numbers on this issue. Chris On 2/2/2015 4:56 PM, Mike Stirewalt via KRnet wrote: > There's been mention lately of ground adjustable props. >
KR> Props
Thats interesting. I'm actually considering a turbocharger (or not) in my build. That, and retracts will depend on medical reform. If they dont change that, then I will build a KR with fixed gear and a flatter prop so as to comply with the 138MPH IAS speed limit of LSA. I'd actually be okay with a simple little KR built to LSA specs and with a great climb. Back when I was involved with KR the last time, around 1990, the Warnke "almost constant speed prop" was popular IIRC. It had the right flex tendencies to flatten out on takeoff then twist back to its natural steeper pitch when forward airspeed was gained. I have no idea how well this really worked or if the owners had a little marketing effects on their impression. If it did work, then you'd have the engine-friendliness of a wood prop, with partial constant speed benefits. I will search the newsletter archives. To: krnet at list.krnet.org List-Post: krnet@list.krnet.org Date: Mon, 2 Feb 2015 15:56:12 -0800 Subject: KR> Props From: krnet at list.krnet.org There's been mention lately of ground adjustable props. If you've got an O-200 a CS prop is the cat's meow but for VW.Revmaster-powered KR's I would suggest a variable pitch prop is completely unnecessary. My first KR had a Revmaster 2100 with the Maloof CS prop. The controller never did work very well so most converted (as I did) to a two-position switch which gave either full coarse or full fine pitch. It's been so long since I sold that plane that I can't remember if I found the ability to vary the pitch to be of any value - but it looked cool. The Maloof was most useful for those who flew high in turbocharged Revmasters. It was only on the turbocharged installations that the Maloof failures occured if I recall correctly. There were only one or two failures, but that was enough to doom the Maloof. I have three props for my current KR - Ken Cottle's KR-1?. When I bought it from Steve it had a Sterba 52 x 52 which would allow me to max out at full throttle in cruise at around 3600 RPM. I was going 170 MPH at that RPM and a lot of the old KR guys who liked to rebuild their engines frequently used to run around at that RPM, but engine temps are through the roof. For reasons of fuel economy and engine longevity I wanted to run full throttle (above 8000 ft.) at a more reasonable RPM. (Steve, BTW, used to cruise this plane at 2900 RPM with the 52 x 52, partial throttle). So I bought a Prince 52 x 54. This gave me a full throttle RPM of 3200 in cruise. I would have kept the Prince on the plane except going through quite a bit of rain on a trip to Mt. Vernon and Naples Florida and back home the leading edges of this prop pretty much dissolved. I ordered a Sterba 52 x 56 (Sterba has good urethane leading edges) which gives me a full throttle RPM of 3100-3200 in cruise above 8 thousand feet. I may get around to sending it back to Ed to put just a tad more pitch in it. 52 x 57 would be just perfect. I'd rather run the engine full throttle at 3000-3100 when cruising above 8000, instead of 3100-3200. I'm usually quite a bit higher than 8K, so the more pitch the better. I get 100 more RPM at 12K than I do at 8K. Why the emphasis on full throttle? Well, the throttle plate in the Ellison is fully open and the engine is breathing unrestricted. As an air pump the engine is at its most efficient when running with a completely open throttle. Below 8000' full throttle would develop more than 75% power with resultant high oil and cylinder head temps and poor economy. Above that altitude full throttle renders less than 75% so for this reason and the reduction in parasitic drag, and for any number of other reasons, up high is the place to be. Flying partial throttle above 8000' is inefficient. Except for takeoff, I really don't want to pull more than 75% power from my engine below 8000 feet. At altitude, 11.5 - 13.5, with my Sterba 52 x 56, I cruise an average of 149 MPH/3.5 GPH using around 50% power. Makes for a happy and long-lasting engine. With my 21 gallons I plan on 500 mile legs stretchable to 600 or 700. I have oxygen, which makes this sort of flying practical. Even down low and using partial throttle, I get more thrust per RPM - more efficiency - with a coarse prop. Engine temps (the VW killer) are dramatically lower with lower RPM. Friction losses (and resultant heat) are minimized. Unless you're based at a 1500' grass strip with obstructions at each end, there's not much reason to use the flat props I see many KR people using and there's no reason at all to use something that's ground adjustable. IMHO. The point of this little prop history is that whether I've got a 52 x 52 turning 3300+ on takeoff or a 52 x 56 turning 2900 on takeoff, my KR accelerates and leaves the ground quickly. The coarser prop is not turning as fast, but it's pushing more air with each revolution. When visiting friends I've taken off at Telluride with full tanks with the
KR> Props
Chris said, " . . . the Warnke "almost constant speed prop" was popular IIRC. It had the right flex tendencies to flatten out on takeoff then twist back to its natural steeper pitch when forward airspeed was gained." The Warnke was and is a gorgeous prop and is a treasure if you can find one with the right diameter and pitch that you're looking for. His daughter took over the business and I've heard didn't do much with it. Lonnie Prince claims some of the same characteristics for his props and I don't doubt that it's true to some extent. His blades have some very complex and beautiful shapes. If he would just get rid of those drag-producing "P-tips" and put some urethane leading edges on his creations his props would be a lot better. Maybe he has done these things . . . I've not been keeping track. Meanwhile, Catto is the way to go for the ultimate in a wood/composite prop. He has incorporated the aerodynamic design work of Paul Lipps into his props and, in fact, is the one who builds those fabulous props (designed by Lipps, RIP) you see on the Reno Biplane racers such as Phantom. http://www.eaa.ca/experimenter/articles/2009-07_phantom.asp Meanwhile, I've got no complaints with my Sterbas. Mike KSEE How Old Men Tighten Skin 63 Year Old Man Shares DIY Skin Tightening Method You Can Do From Home http://thirdpartyoffers.juno.com/TGL3141/54d05a481b8f85a482855st03vuc
