CHT Part #4 more notes
Builders:
I received an email from a builder that gave me a moment to pause and think about communication, and what people are willing to read into things. The letter was sent by a good guy, and I have deleted his name because I want people to focus on the comment, not who said it. Here is the sentence from his email:
“In view of your modification of the inlet size for the Wagabond, would you recommend I do the same on a standard two-piece nose bowl for my plane? Did you make the mod preemptively, or was the Wagabond running hot? Thanks in advance”
Now, all this week I have been writing about cooling, and specifically linking to many articles that I have written in the last 20 months. The photograph and caption listed below is in a story that was directly linked to a few days ago. Read it and see if you think I the Wagabond was running hot as the letter writer asks:
Above, a real world proven Corvair system, the Wagabond cowl. Note that the air inlet is a simple 4.875″ hole in the cowl. This aircraft has flown at the record gross weight for Corvairs, it has always lived in Florida, it has a very large airframe with plenty on drag to spare, and yet it never ran hot, even with a front alternator and no inlet cooling rings. Why? because Corvairs have excellent cooling. builders can either utilize this success or they can ignore my suggestions. If they chose the latter and it doesn’t work, they rarely see the problem as a people issue. For some reason, a fraction of builders will focus on stories of people who has trouble with one-off ideas rather than looking at all the people who are flying proven ideas without issue.
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This while series started because I was angry about people offering the unfounded opinion that Corvairs inherently ran hot, and that the cowls we offer and the way we teach people to cool the engine does not really work. Over the last several nights the stories I have written have been to counter these ‘opinions’ with facts and data, and offer links to show that this cooling is not an issue with Corvairs. The last sentence in his note indicates to me that some people are not really reading what I have to say, and my words are competing with a predisposition on their part to still believe that there is something wrong with the cooling as we build it.
I don’t blame the letter writer. He is exposed to many people talking about Corvairs, and at times it is hard to keep sorted out who has an ‘opinion’ and who has been testing and flying. This is why I was annoyed in the first place with people who have never owned a flying Corvair spreading rumors that “Corvairs need 6″ inlets”. On one hand it is just a lot of background static, but I am of the opinion that some of it sticks even when the recipient doesn’t consider nor remember the source. If you are new to a subject, be very discriminating when you choose to listen to people. Adopting perspectives, even partially based on false opinions it at best, a tremendous waste of time and energy.
To me, the really ironic thing is that their are other alternative engines that really do have cooling issues that are very hard to solve. The Corvair is nothing like that. Yet the ‘buy it in a box’ imported engines with actual cooling issues probably generate less internet discussion than the Corvair does on this topic. Part of the reason is that the people buying those are largely shopping for an appliance, and people coming to corvairs are supposed to be here to learn about a machine. The latter should generate more discussion, but talking about things is not the same as learning, especially when much of the conversation is opinion, and when fact must compete with rumor during the phase where the new builders understanding just developing.
The post I put down last night was number 365 since we started this blog. Give or take, that is a quarter of a million words. If I tasked you with typing a 250,000 words that were educational and entertaining or gave you the option of building a two place kit aircraft, which would get done first? I type about 20 wpm, (not counting time spent staring at the keyboard) so I could build the plane much faster. I still consider the time well spend, under one condition: People actually read the content.-ww
CHT part #3, Letters, notes, sources and inlets.
Builders,
Here is another block of information on CHT and cooling, along with data from flying pilots. This is a collection of notes and loose ends that adds a little more dimension to the first two parts.
Above, The Wagabond nose bowl last night about 3am. I have been having a run of insomnia lately, and have been dividing up the hours in the middle of the night between writing, doing a little work on the Wagabond and reading Morris’s Colonel Roosevelt, a rich biography of TR from when he left the White house until his death. When I am this tired, I don’t make customer parts, but I will work on my own basic stuff like nosebowls. Last night it was more than 70F in the hangar. Not a bad temp for glass work. I bonded in the inlet rings seen above. They not only give the cowl a much better look, they are also functional. A lot more air will flow through a 5.125″ tube, even a short 1.5″ long one, than will flow through a 5.125″ hole in a flat plate. These rings are made out of PVC pipe, but you could actually make them out of just about anything. This is the biggest size I think any Corvair needs, even on heavy slow climbers like Zenith 750s. This original one piece nosebowl is dimensionally the same as the two piece models we sell today. It has an altered line where the sheet metal of the cowl meets the nosebowl to make it fit the Wagabond better and the ‘tunnel’ in it is the beginning of the shape that flows into the J-3 airbox/filter that the plane is set up to use.
Above, a detail look. The white ring is PVC, it is bonded in with West System epoxy thickened with silica and flox. The section of paint stick and the sheet rock screw are just working as a clamp. If you look close, you can see that the tube flares out slightly on the ID near the end. It isn’t needed, but it will not hurt. Epoxy theoretically doesn’t stick to PVC, but it will get a mechanical bond if the surface is rough enough. This nose bowl is 10 years old. It may look a little rough, but well made glass parts hold up even on hot engines and over long lives. If you look closely, the marks show that it was vacuum bagged into our mold. the part had the image of the bagging plastic in many places.
Above, a bigger view. I ran 3 sheet rock screws through the part to pin it to the table after I covered the table top in plastic sheeting to prevent sticking. The screw holes don’t matter because they are in the section covered by the spinner. The two inlet rings are being clamped down by the sticks until they hardened. You can immobilize many things to a wooden work bench this sheet rock screws. Again, 5.125″ is probably too big on all except the slowest climbing planes in hot weather. Inlets size doesn’t cool by itself, it has to be matched with outlets and good baffling.
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Mail and comments:
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Letter from 2,850cc 601XL builder and flyer Ron Lendon:
Ron with his plane at Brodhead 2012.
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WW, it’s not that I don’t enjoy the reading I miss the succinct data and would like to have a place to quickly look it up. Perhaps in my spare time now that the plane is flying with the correct carb. No I didn’t volunteer to do it. The calibrated CHT gage you allude to, is it available to those of us with short attention spans also? I have the Westach gage and rarely see the CHT temps go above 350F on hard climb in the more temperate climate we have here in Michigan. I’m using the ring type connection at the GM location.”
Ron, I looked on Ebay and other places to see who was selling Mil.surp. gauges but didn’t find anything noteworthy. I found mine at the Oshkosh flymart. Get a look at this link, it is to Dakota Digital, a company that makes all their stuff in the USA. http://www.dakotadigital.com/index.cfm/page/ptype=product/product_id=347/category_id=248/home_id=59/mode=prod/prd347.htm
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Letter from 2,850cc CH-750 builder Blaine Schwartz:
Click on: ( Zenith 750 Builder Blaine Schwartz )
“William, Thank you for such an informative essay! Carl Sandburg once wrote: “Experience is the greatest teacher”. You are a first-class example of proving his premise. Blaine”
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Letter from 3,000cc PC Cruiser builder Sarah Ashmore:
“I find it difficult to understand why anybody feels they need 6 individual CHT readings on a Corvair. Lycomings and Continentals have a CHT on each cylinder because each one is truly independent and subject to different cooling and heating rates. The Corvair is one big block of aluminum, a material which conducts heat rather well, so it should be fairly uniform in temperature regardless of what is going on in the cylinders. One on each head is good enough for me and I have already purchased the special size bolts along with the other hardware for the engine build. And cooling is not something I like to do the hard way either. My variation on the Personal Cruiser will have a 30″ wide firewall instead of the stock 22″ but I have your generic nose bowl and a set of generic Weseman baffles all ready to go on it. All I have to do is make sure I follow your recommendations on the cooling air exit and I would expect the test flights to have no surprises with regards to engine cooling. There is enough experimental in my aircraft already so I choose my innovations wisely. A good pair of articles in a long line related to engine cooling.”
Sarah, there are also a lot of certified planes like C-150s and 152s that don’t have any CHT at all. 6/cht-6egt combos mostly appear as an option on big injected engines in fast certified planes like Bonanzas, where owners are trying experiments in extreme leaning and early top end replacement. Although Dan Weseman has a 6/6 combo on his plane, just the other day he was saying “what is wrong with a little too much cooling?” implying that no one is setting a record here, so why not sacrifice a few mph cooling drag to have an engine that always runs very cool. It fits in with your idea of leaning to the proven side rather than the edge of the envelope.
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Letter from 2,700cc 601XL builder and flyer Dr. Gary Ray:
Click on: ( 601XL-2700cc Dr. Gary Ray )
“William, Thanks for this post. I read and re-read everything but this brings all of the temps, measurement locations and expected results into one post. I have my 601XL-B setup as you have shown and I am experiencing the same results. Until recently, I have taken all CHT’s from beneath plug #3 and #4. The highest temp I have ever seen has been 430 F on its maiden flight when I only measured plug #3 , otherwise it can get to 410 on high heat days during a 90 mph sustained climb. I now record temps on both sides from the bottom #1 & #6 locations. During the last 50 hours I am seeing a maximum temp of 315 F on the worst days and a spread between sides of less than 10 degrees. Measurements show approximately 80-90 degrees lower temperatures between the top plug position and the lower GM position. The gauge is a four channel MGL device for CHT and EGT’s and it produces comparable results to the temperature compensated analog meter I had used before. It reads about 10 degrees higher and has a thicker washer type thermocouple which likely accounts for the slight difference. In cruise at 3000 rpm, 9.75 degrees at the tip Warp Drive, 21.5 MP, 65 OAT, CHT’s read 270 degrees. EGT’s taken at 12 inches downstream from the last exhaust port are 1200 to 1300 and will go higher if leaned more aggressively which I do not do.
Current Set Up: Maximum advance on the timing is set to 30 degrees, 100LL fuel only, Inlets size 4.75″ with inlet rings, Outflow is 3.5″ x 24″ which is 2.4X inflow area and the bottom edge is rounded. Metal tape over cowl hinges above plenum and tight baffles. The Niagara oil cooler reduced maximum oil temps by 30 degrees (now 210F). Normal climb is 90 mph. If I see temps near 310 F , I increase air speed by reducing my rate of climb which seems to work.
It is nice to know that there is such a large margin over normal operating temperatures before overstressing the engine. The engine runs with a very low level of vibration. Just how low is really apparent when I am in dead calm air. This is when I start patting myself on the back for choosing the right engine.”
Pietenpol Mount on airframe
Builders,
Piet builder Mark Chouinard sent in a photo of his Corvair motor mount on the front end of his plane. The airframe exhibits outstanding craftsmanship, and looks to be in the “light at the end of the tunnel” phase. From this point forward the pace of work tends to increase.
When new guys set started they find it hard to visualize how much more productive per hour they will be in the second half of the plane. Your skills will be far better, you will find a work schedule and rhythm that fits your life, you will have many trusted fellow builders to share info and enthusiasm with, and with enough persistence, you can see the light at the end of the tunnel.
Mark’s plane is a traditional Pietenpol with a number of nice details. The landing gear combines traditional wire wheels from a straight axle gear with J-3 style independent suspension. Disc brakes are modern but appropriately sized. This view gives a good look at the Pietenpol’s structure. Mark has wisely left off the outter skins on the front of the fuselage until everything is built and rigged inside. The Gray powder coated Motor mount we made for him is one of our “High Thrust line” motor mounts. Below are some direct links to Pietenpol stories in our archives. The first three explain the concept of a high thrust line mount.
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Pietenpol Motor Mounts, P/N 4201(C)
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Pietenpol Products, Motor mounts, Gear and Instalation Components.
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Pietenpol Power: 100 hp Corvair vs 65 hp Lycoming
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Three Pietenpol Motor Mounts
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Making a House Call on 1,000 Hour Pietenpol
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New Pietenpol #3, Mike Groah, Tulare, California
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New Pietenpol, Gary Boothe, Cool, Calif.
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Pietenpol review in pictures, 15 more Corvair powered Piets
From our Brodhead 2013 coverage: “After the Forum, we conducted a Tailgate Tech Seminar. Piet builder Mark Chouinard, extreme right, extreme tall, listens as I answer questions. Mark picked up one of our high thrust line Piet Mounts for his project. Jim Boyer of California picked up another one at Brodhead for his Piet. That rounds out the first 10 of these new generation Mounts. While I have previously made Motor Mounts according to the original drawing, all of our Piet mounts from here forward will be high thrust line models.”
Corvair vs O-200…. weight comparison
Builders,
A Zenith 701 builder that I spoke with at the open house wrote me a short note asking some questions about the weight comparison between these two engines. This is something I have directly compared, something we have very good data on, and some valid and useful commentary.
For people with short attention spans, I will cut to the chase and say that a modern Corvair, as we teach people to build them, with electric start and a charging system, weighs the same installed as a standard O-200 Continental. You can see in the photo below that I have weighed, thrust tested and dyno run them side by side personally. Many people will comment on the subject of engine output and weight on power plants they have never laid a hand on, far less run on a dyno. Most of the “evidence” people present is well intentioned, but erroneous just the same. Bad data, presented with good intentions or malicious ones, is still bad data. The numbers here come from personal measurement, intentionally done in public for people to see.
“More Lies are told in experimental aviation than in singles bars” is a saying I made up 15 years ago to illustrate the loose association with truth that many people in our field have. The most common fib told in home building is under quoting how much something weighs. (This is ironic, because compared to numbers like HP output, true stall peed, or ultimate G strength, the weight of anything is a very simple matter to check, but very few people ever do.) Many people I quick to point the finger at salesmen, but let me also say that I have done the weight and balance on something like 100 homebuilt aircraft, and only found 10% of the owners were remotely telling the truth on their W&B sheet. Many of these people told their buddies their plane was exactly 100 pounds lighter than is was. Frequently they repeated it often enough that they forgot they made it up, and could have passed a polygraph test swearing to it. Take this away: Don’t believe anything you hear about weights unless you are listening to the guy who did it himself, who has photo documentation of him doing it. If you would like to read a funny story about how reality has a hard time competing with fantasy, take a moment to read this link:
Unicorns vs Ponies.
On the left above is the Continental O-200 as removed from a 1959 Cessna 150. This engine is considered the standard against which all other 100hp class engines are measured. It is a direct drive 4-stroke, 4-cylinder engine of 200cid. It carries a horsepower rating of 100 at 2,750rpm. I have read that Continental produced about 50,000 O-200s. On the right is a 170cid Corvair engine. For size comparison, the O-200 is 32″ wide without the baffling. The Corvair is 28″ wide.
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The caption in italics above is actually nine years old from our main page flycorvair.com. It is from a long test series on dyno and thrust testing the O-200. You can read the full story at this link: http://www.flycorvair.com/thrust.html . The picture above shows that a Corvair is smaller physically than an O-200. Let me also offer that I know a bit about Continentals and I like them. Graces Taylorcraft has an STC’ed C-85-12 in it, an engine that is nearly Identical to an O-200 in physical size and weight. Keep in mind that when people compare engine weights on the net, very few of these people have owned both of the engines they are commenting on, and in many cases, the guy offering the data has owned neither. It doesn’t make then bad nor evil, it just means their data on this subject probably isn’t good.
What about the often quoted 188 pound weight for an O-200? That is erroneous, as it does not include the starter, mags, plugs, carb, oil, or many other items it takes to run the engine. The data was actually presented that way so if a manufacturer chose Eisman mags instead of Bendix, he could do a weight and balance engineering solution on the engine. The 188 number was never meant to be a comparison all up weight.
What about the new light weight O-200? Yes, it is lighter than a traditional model, by as much as 20 pounds. But this engine, which Continental rep. Kim Winner brought to the Zenith open house, sells for $20,000. It is new, and they have made very few of them, and you are not likey to come across one for sale used for another 20 years. Many of the parts in it can not be used on older engines. Most builders are taking about a Corvair they could build on a $8500 budget vs a traditional O-200 taken from a Cessna 150 for roughly the same money. If you want to spend $20K, I can build you a Corvair that is far lighter than the lightest O-200 ever made. Given $8,000 or $10,000 just to spend on weight reduction, much could be accomplished, but that isn’t an engine most people are considering, and neither is the new light weight O-200.
Is an O-200 ‘Approved’ for a 701 but not a Corvair? You can call Zenith and speak with Roger or Sebastien, and I am sure that they would advise any 701 builder to first consider lighter engines. But they would also tell you that both engines have powered 701s before. We bought our 701 test bed kit directly from the factory in 2005 and completed it in 2007. Sebastien sold it to us to test the concept after seeing the success of our 601/Corvair program. The 701 worked. we made no attempt to lighten the Corvair for it, and the plane weighed 677 pounds ready to fly. (if that didn’t sound very light compared to other numbers you have read on the net, go back and read Unicorns vs Ponies again.) It did not need any ballast whatsoever to get into the CG envelope. On this last point, the Corvair has a distinct advantage over the O-200; The Corvair is ‘flat’ on the back, and can be pulled right back to the firewall without creating a maintenance issue. An O-200 has the mags and wires sticking out the back, and they require several more inches of clearance to be removed without the requirement of pulling the engine off the mount. Although the Corvair and the O-200 effectively weigh the same, you can’t get the O-200’s CG nearly as close to the firewall. It may require ballast just to get into the front of the CG range.
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Above, Our test bed Corvair powered 701 in the Zenith booth at Sun n Fun 2010.
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I have heard that a heavy engine can break the 701 nose gear, truth? Yes, a very heavy engine could be a factor, but when we built our 701 I studied this closely, and a far bigger issue was people flying the plane forward of the published CG envelope. One guy had tried a Geo engine with a belt drive on a 701. This was actually lighter than a Corvair, but the engine layout was very long, and it had to be positioned well forward to clear items from the firewall end of the engine. The result was I guy flying around 2″ ahead of the forward CG limit. The plane could be landed smoothly by rolling it on at 60 mph, but that wasn’t the point of the 701. When the Geo guy tried landing slow and pitched the nose up, he found out that planes that are ahead of the forward CG limit drop their nose like a rock at high angle of attack. This is the effect that harms the plane. It is actually a CG issue, not a weight driven one. Poor pilot technique is another big factor. Any guy willing to get a little time in type training and fly within the published CG range has little to worry about.
What about reasonable cost Corvair modifications to reduce weight? A 3,000 cc Corvair actually weigh 7 pounds less than standard ones becase the bigger engine uses a lighter aftermarket cylinder set. A billet crank is nearly 4 pounds lighter than a stock one. A welded pan is a pound lighter than a billet one., etc. There is a list of parts than can get 15 pounds off a Corvair, but most builders find the engine to be acceptably light in the basic form. People frequently ask about putting aluminum cylinders on Corvairs. I have been working with Corvairs for 25 years, people have been talking about these for at least 12 years, and yet no one has ever taken a set flying. I have good reason to doubt the would work. If some one tries to talk you into anything that has never flown, and the national expert doubts will work, realize they want you to be a guinea pig. They sell down at the pet store for $20, and if your life is worth more than that, don’t be anyone’s Guinea pig.
Last Comment of weights: Two people in the alternative engine game, myself and Robert Helms, president of UL power, never hesitate to tell the truth about how much our respective engines weigh. Robert has nothing to loose by doing so; He has the lightest engine on the market, he doesn’t need to embellish the facts. In my case I don’t have anything to gain by under reporting the weight of a Corvair. People choose the Corvair because it is affordable, smooth, a learning experience, well supported, made in America and a multitude of other reasons. It has the features above, while having an acceptable level of weight for a broad variety of aircraft. If I fibbed about the weight of the engine I wouldn’t attract any significant amount of new builders, but it would undermine the trust and rapport with builders we already have in place.-ww.
Corvair Motor Mount for Bearhawk LSA
Builders:
Below are photos from my road trip to meet with Bearhawk designer Bob Barrows. The result is that we now have a Corvair to Bearhawk LSA mount. While many alternative engine people apply their engine to aircraft against the designer’s wishes, I have never promoted such combinations. It is far better to work with the designer. Many designers have specific reasons why some alternative engines are a poor match for their airframes. Engine people who ignore these points are not doing any builder a favor by selling such engines to builders. They are either driven by the zealous belief that their engine is the answer to every need, or they are motivated by greed, and neither of these is a good reason for a builder to work on such a combination.
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Our work with Bob on his airframe design exemplifies the opposite approach. We spoke of the combination several times over the past few years, but it was not until this year that Bob chose to closely study the combination. As I mentioned in a previous story, he is Mr. Old School and conservative, and earning his evaluation meant far more to me than having a half dozen company salesmen elect to make Corvairs an option for their builders.
Above, a look at the result. This is a factory built, deluxe Bearhawk LSA fuselage with our Corvair, sitting on the mount that Bob and I worked out in a day’s effort. The thrust line is only 1″ lower than standard to clear the Corvair’s starter. Bob calculated 1 degree down thrust, and set the engine straight in the fuselage. The engine’s datum line is 10.625″ ahead of the firewall. We set it up to accommodate our 2901S gold oil filter housing and a 2950 rear alternator. The arrangement actually uses our standard intake 3601S and the same exhaust that fits a Zenith, our 3901A. This engine has an MA3 carb on it. It is in a very good position with respect to gravity fuel flow and keeping it above the lower longerons for safety.
When we write a story, I type the words, but Grace puts all the pictures in place, because I am a moron around computers. I can move them from one spot to another, but I am terrible at downloading them from any of our cameras. As a consequence, I ask Grace to start the storyboard by putting in the pictures. While we have 70 full camera cards of pictures, at least 1/3 of the images are of the Dog, and Grace likes to insert “Gratuitous Dog Photo” in every story. Above, Scoob E at CC #26. Dan Glaze taught me the phrase “Happy Wife, Happy Life”. Words of wisdom.
We had to drive away from our place in Florida at 6:30 a.m. in order to make it all the way to northern Georgia by 2 p.m. Above is the dog’s enthusiastic response. Grace felt much the same way, pointing out that “I will get to see Bob at CC #27 shortly, have fun, tell Bob we say hello.” Grace and Scoob E were real troopers on the 2,400 miles to CC #26 in Mexico, so they took a pass on this one.
Above, Bob working on the same plane, but with a Continental case. Bob’s base engine for the design is the small Continental. He used this opportunity to check his base mount on a production fuselage, and then we did the Corvair mount. Bob is a hardcore builder, and quickly shaped all the tubes in his mount. We tacked them with my 220V fine wire MIG welder. The alignment was checked many times in the process using a variety of levels and plumb bobs.
Above is the Corvair mount in process. The yellow string is the airplane’s thrust line, that is why it is offset in the main bearing bore of a spare case. The basic mount is built on one of our standard trays, part number 4202.
Above, the top view. The Corvair is 28″ wide, several inches narrower than a Continental. The Bearhawk LSA is 31″ wide. This is about 10″ wider than a J-3 cub. At first, the number sounds almost too big, but after we made the mount, Bob took me out flying in the plane, and everything seemed just right. At first Bob just said I should go fly it myself, a great compliment I am smart enough not to accept. Although the plane flew very well with no bad habits and struck me as easy to fly, I still had a vision of becoming instantly famous in the EAA as “The Jackass who ground looped Bob Barrow’s plane.” I was very happy to let Bob do the TO and landing and the majority of the flight. The plane was the very pleasant combination of light on the controls but with positive stability on all axes.
Above, Bob on the left with his builder Rolly. He was very helpful and a great sport about letting us have full run of his hangar.
After the work on the mount was done at noon on day two, Bob packed up and flew back to his home base in Virginia. Instead of a long ride directly back to Florida, I opted to drive over and see my sister Alison and her husband Col. Nerges at their place in Charleston, S.C. A number of builders met John and Alison at CC #24 in Barnwell last year. Above, John and I goofing around on the 3rd floor deck of their super-cool home, which is right on Charleston harbor. If you look closely you can see the Ravenel bridge in the distance. No one who is 50+ really looks good in a close-up, but it is always great to spend a few hours with family.
Funny Suburban story. Although we have just had our new ride a few weeks, it has already logged 3,850 miles on road trips. It gets about 12-13 mpg towing the trailer and is very comfortable. Every friend of ours who works in aviation thought it was neat that Northrop-Grumman was the previous owner. Many of them who rode in it commented that it even smelled a little bit like aircraft. Our friend Paul Salter, who works at NAS Jacksonville, specifically said that it “really smelled a lot like a P-3 or an EA-6B” inside. I was kind of convinced that it was the black rubber floor mats in the Florida sun. If you work on planes for 25 years, you even learn to love the way they smell. Just this morning when I was doing a detailed clean up, I found the source. In the back, in the pocket where the 3rd seat would have been mounted, was roughly 4 ounces of Jet Fuel. In the photo above I am sopping it up with paper towels. (There was enough that I was afraid to let the Shop-vac inhale it.) Grace got a big laugh when I showed her and she said “I love the smell of jet fuel in the morning.” Happy wife, happy life …-ww.
Bearhawk LSA, Corvair motor mount in development
Builders,
I will be out of the shop Monday and part of Tuesday. I am headed to North East Georgia where Bob Barrows and I are meeting at the shop of one of his Bearhawk LSA builders. I am bringing up a Complete dressed out Corvair engine and enough equipment to develop a Corvair/Bearhawk LSA mount. While theoretically this could be done other ways, Bob is old school, and there is nothing like having all the elements in one place, even if the logistics require a little work. It is a 6 hour drive for me to get there, and Bob is flying the LSA prototype down from his airfield in Virginia, about 3.5 hours airborne. His plane has 30 gallon tanks, and his trip will be non stop on less than half of that.
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Above, a small photo of the Bearkawk LSA. At a glance, it looks like many traditional aircraft, but in person it is easy to see that it is nearly 10″ wider than a J-3 and has all metal wings with a modern airfoil and single strut bracing. Bob is bringing this aircraft to display at CC#27 at Barnwell SC in November.
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I will have pictures and more stories upon my return. I will be back to cover email on Tuesday night, and will be back in the shop and at the regular phone on Wednesday.-ww
Larry Hudson, Master Upholsterer, parts and core for sale
Builders:
We have just returned from a very successful CC#26 and Zenith open house. It was a great time, and over the next few nights I am going to write up all of the stories and moments from the trip. For tonight, a simpler task to get back into daily writing and updates; Let me share a few notes on Corvair builder and friend Larry Hudson.
Larry is a master automotive upholster and top craftsman. He comes from a family that has worked this craft for several generations. After Oshkosh I dropped off the seats from our Wagabond at Larry’s shop in Indiana. As I said then, it is no average production shop, the main car they we doing at the time was a 1959 Caddy Eldorado coupe in coral pink (a factory color). Larry is a guy you can trust with a unique interior in a car worth more than $75K. As seen below, he also does outstanding work on aircraft that are worth a small fraction of that. Larry stopped by CC#26 to drop of the seats. Larry knows that I like dirt simple aircraft with no frills, but said “Just trust me to do something good and simple…I will make it look old school and appropriate.” All I did was tell him the colors I painted the plane (Insignia blue and Nevada silver), mention that I like very firm seats, and he did the rest. The price was reasonable, the quality outstanding, and I think they are very tasteful. I sat in it today, and it was great.
Above, the seats back in our plane in our hangar. Our Wagabond started out life as a 1964 Piper Colt, and although it is highly modified, it retains the lightweight, folding, independently adjustable, quickly removable seats of the late model PA-22’s.
The seats are half vinyl half cloth, with custom made beading made from the cloth. The computer is making the cloth look shiny but in person it isn’t. I am always glad to mention the craftsmanship of builders we know, and this case is no different. If you are looking for interior work on your plane, give Larry a call and talk it over with him, he is a very friendly guy and a first class craftsman. His number is 317-965-2428.
Also, Larry wanted to mention that he has a fuselage for sale. It is a 1952 Piper PA-20 pacer, with the tail and landing gear, a mint set of Cleveland wheels and brakes and many other small parts. Like many of us, Larry has too many projects, and he is trimming his aircraft herd down to his own PA-22-108 and his Corvair powered Fokker D-VIII. The Pacer fuselage is identical in size to our Wagabond. Larry has a set of Wag Aero plans to go with it. The FAA frowns upon directly using parts from previously certified aircraft in homebuilts today, but people still do it with the assistance of a friendly and partially blind DAR (this is when they overlook things but can still see the color Green) If you are interested in the fuselage and parts give Larry a call he is asking $2,000. It would save a lot of work on a Wagabond project.
Also, Larry has a Corvair core engine in good shape for sale. The top end has late model 110 heads, but the bottom of the engine is from a 140hp model and has a factory nitride crank. If this crank is in good shape, you can have it cleaned, magnafluxed and polished, mate it with a Gen 1 Dan bearing and use it directly, a bargain in building and a time saver. He is selling the Core for $375, and it is complete. He is planning on traveling to CC#27 in Barnwell in November, so if you buy it but live on the East Coast, perhaps he can meet you at the college. -ww
Blast From the Past, Corvair College #4, 2003. Above, Larry Hudson and his son Cody working on the Corvair that is in their Fokker D-VIII today. Over the years Larry and his family have been to 10 Colleges. Long known as a good source of core engines in the Midwest, he has often pointed out that he has found more than 60 within 40 miles of his house. Further proof that Corvairs are still plentiful everywhere.
Deal Of The Day, early generation hub…(Sold 2:11 am, 9/3/13)
Builders:
Today’s deal of the day is an early generation black hub / starter and alternator arrangement. These parts actually flew on our Zenith 601XL in 2004. They have been used on another test engine. The parts are used, but in fairly good condition and airworthy.
Before there were Gold hubs and 5th bearings, this was how Corvairs were converted. Today, there are still a great number of aircraft in the Corvair fleet operating systems identical to these. This set up can be directly used on a 4 bearing engine, or it can be used by a builder using a Gen. 1 Dan Weseman bearing.
If a budget minded builder wanted to use this with a 5th bearing, it would require the hub modification and a switch to gold starter brackets. It would still be an economical proposition. The ring gear is an FRA-235, the style we have not used in 5 years. Today we use disc style ring gears that do not have spokes. If the edges of the spokes above are polished to remove stress risers, they have a good track record. Otherwise they are prone to developing cracks in the spokes. I put a lot of effort into explaining the concept and asking people to periodically inspect these, but many builders did neither. Today, all of these are eliminated by only offering the disc style ring gear, but for builders willing to put closer effort in, the spoked wheels was more than a pound lighter. If a builder wanted to upgrade to a disc style ring gear on this arrangement, it will bolt right on.
This is a good opportunity for a builder working to a tight budget to get launched on an affordable engine.
The parts in this package are:
Black hub, Ring gear, puck, front alternator pulley, starter, brackets, tail bracket, alternator brackets, 20 amp alternator, and drive belt.
These parts cost more than $1,250 new. As the ‘Deal of the day’, we are selling them for $475.
If you would like them, email me directly at:
WilliamTCA@aol.com
I will cover the shipping in the US.-ww.
Deal of the Day, simple MA3 carb. (Sold at 1 am, 9/1/13)
Builders:
Here is the next “Deal of the Day. It is an MA3 carb. Please note that it is not an MA3-SPA, the primary carb we use. The difference is that the SPA model has an accelerator pump, which also does a good job as a primer. Additionally, this carb does not have in flight mixture control. Functionally, the carb below is much like a Stromberg NAS-3. The person who puts this on their plane is going to also install a primer. This isn’t a big deal, and virtually every plane that has a Stromberg or even an Ellison has a primer. Only the MA3-SPA gets away without using one. I am thinking the most likely home for this carb is a Pietenpol or other fairly simple type of plane, but it does have the ability to withstand fuel pressure, so it could be used on a low wing aircraft with fuel pumps. It is not restricted to gravity feed like a Stromberg.
Why not just use an SPA instead of this MA3? Simple: Cost. The Core value of a rebuildable MA3-SPA is $500 to $600. This carb, which I am pretty sure will run as is, and is certainly a great candidate for a simple tune up (the throttle bushings on it are in very good condition, this is the hardest part of a rebuild). We are selling this as is for $150.
Above, carb is dusty but complete. It will bolt directly to our standard intake manifold.
It has a short throttle arm, but this can be replaced with a longer one. This uses the older style arm which is worth a lot less than the new style one.
