Builders:
I wrote the following words on our traditional website in January 2011. I am reprinting them here because I want to have them as a stand alone story that I can link to, and because I think that they are a good piece of ‘plain talk’ and commentary. They cover building and business philosophy, and they are just as true today as they were when I wrote them. People who have not met me should read the 9 points at the end, they will make many things about our approach easier to understand.- ww.
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Corvair Outlook 2011
I started typing this update on January 20th. On that date exactly 50 years ago, JFK gave his inauguration speech including the famous words: “Ask not what your country can do for you, but what you can do for your country.” It is a very stirring speech, yet most people have never seen it in its entirety. It is well worth taking the time to watch it on the Internet. A majority of Americans, myself included, were not yet born 50 years ago. However, most of the people in experimental aviation are old enough to remember that day. Today, people are bombarded with messages at a rate that was inconceivable 50 years ago. The predictable effect is that none of it sticks, none of it moves anybody, and a few kernels of wheat are most often buried in a mountain of chaff. If you’re young, it is very difficult to imagine how powerful JFK’s speech was as a motivator to his “New Generation of Americans.”
On January 18th, 2011, Sgt. Shriver, JFK’s brother-in-law and the first head of the Peace Corps, passed away at age 95. He spoke countless times about how JFK’s inaugural speech was a summons to action for the Peace Corps volunteers. Opinions differ on the net effect of the 1960s on American culture. But on this day, it is well worth remembering that the era started with great ambition on a very high note. What words on a page could I write that would similarly charge you to take the reigns of your own aviation goals this year? While JFK’s message was a challenge to young Americans to take their place in the world, homebuilding is conversely a challenge to yourself, to essentially take your place as the cognizant commander of your path, an opportunity to measure your own worth and potential where the rewards are very real because the subject is serious, and the tasks are intolerant of lackadaisical attitudes of dilettantes and posers.
There are roughly 335 days left in this year. What you will accomplish in aviation this year is still an open question. Most people who are yet to start a project incorrectly believe that external circumstances dictate the odds of success. Let us squarely address the largest external factor; the vast majority of Americans traditionally involved in homebuilding have earned between $25,000 and $65,000 a year. The educational background and the ambitious nature of these homebuilders have previously insulated them from the ups and downs of the economy. However, our same group, due to loss of manufacturing jobs and outsourcing, has felt the real bite of this recession. A lot of magazines in our industry are afraid to say this, but it is reality. The acknowledgement of it will not deter a real homebuilder. It may alter his plans, change his timelines or readjust his goals, but if it makes a builder quit experimental aviation outright, perhaps homebuilding was not one of their more closely held dreams.
The real factor that counts in homebuilding success is internal, not external. Simply put, do you believe you can? Are you interested in a real challenge or is drifting through acceptable? Once started, will you find the task of creating things with you own hands rewarding enough to keep you going all the way? These are the only things that matter. External factors, no matter how strong they seem, are not the major determinant. The largest single factor is your determination that this will be your year and your will to carry it through. Tacked up on the fridge in our house is the simple phrase “Do not be optimistic nor pessimistic; be determined.” In the Corvair movement, your planning, determination and will put you in the company of some first class characters. You deserve to take your place among them.
Think about this: A guy can be from your hometown, be the same age as you, have the same number of kids, live in the same kind of house, etc., but just because you bought the same kind of car he bought, no matter how unique or sporty, in reality, you have nothing of substance in common with this person, you’re merely two car consumers. You both might be great guys in your own right, but merely owning a product in common, no matter what advertising agencies want you to believe, doesn’t give you a real connection, or any common understanding. Conversely, if you choose to build and work to create something as unique as a homebuilt aircraft, the story is totally different. A person of a different generation living in a different place and perhaps even speaking a different language who also chose to build an aircraft overcame the same self doubts and pessimism of people in his day-to-day life, learned the same skills and met the same challenges, and is certainly a brother of yours. The external differences in your lives of circumstance and place, things that were not your choice, are not what define you. Your desire to build and your determination to see it through speak volumes on your character that situation, circumstance and consumerism will never reveal.
If the economics of the past two years gave you pause, made you stop and look at the choices we all make in life and truly examine the alleged rewards of typical consumer goods vs. real challenges and adventures in life like homebuilding, then some good came of it. Anyone reading this can decide today that this will be their year in aviation, the year that was the turning point, from which they made real and steady progress. Likewise, everyone reading this is fully capable of spending the next decade in front of a TV or computer screen, entertaining themselves. I don’t judge people by their choice. I have more friends in the latter category than the former. My sole point is that I know for myself, happiness lies in the hours spent in the shop, not in the living room. I am here to work with anyone who feels the same way.
I don’t like to dwell on it, but I’m middle aged now (much, much, much older than Grace), and I’ve lived long enough to look back with some perspective on choices I’ve made. Buying something has never made me happy like creating things does. Nothing I started that had a certain positive outcome felt rewarding when I got to the end. Only challenges ambitious enough to contain the possibility of failing resulted in feelings of victory and accomplishment at their successful conclusion. This isn’t particularly insightful; we all know this at some fundamental level. Reading this drags the thought out front and center. Will you define your challenge and make your plan tonight, or will you have another year drift by?
This month brings the Superbowl. I was born in Pittsburgh, and have been a fan back to the Mean Joe Green era. I am sure Grace and I will watch the game somewhere in the company of both aviation and non-aviation friends. After the game is over, I may not watch another game for a year or two. This doesn’t make me a better person than my friends who will spend countless hours on the couch holding a remote. It just makes me different. At the end of each day, I would just prefer to be one day closer to flying something I built with my own hands. There is nothing wrong with spending your hours in either method. The only tragedy would be knowing that you are a builder, but you didn’t take your shot, for reasons that will seem small and petty when the possibility is finally gone.
Our Work In Print: The Hat Trick – BPAN, Sport Aviation, Kitplanes
2011 started off right with three major publications running very favorable articles about our work with Corvairs or our expertise with aircraft systems. Tim Kern, the most engine savvy writer in the EAA’a stable, wrote a very nice piece about us for Sport Aviation. Rick Lindstrom, who has written for Kitplanes for more than 20 years, wrote a piece focused on our collaboration with the other members of the “Corvair Consortium:” Mark Petz, Brother Roy, and Dan Weseman. The Brodhead Pietenpol News enjoys one of the largest circulations of the Type Club newsletters. It is produced by Doc and Dee Mosher and is available by visiting their http://www.Pietenpols.org Web site. If you want a look at his picture, it accompanies the Introduction Doc wrote for our Conversion Manual. Ryan Mueller and I teamed up for a very lengthy article on weight and balance calculations for BPAN. These publications vette their sources on long articles carefully. It is an achievement to be in any of them. Three in a month is unheard of. Many alternative engines and their promoters go 5 or 6 years without this kind of exposure. We got it not because I am brilliant nor charming. We got it because I worked very hard at becoming educated in aviation, I have been doing this for 22 straight years, and I have always been willing to enlist the support and acknowledge the input of other qualified people of good character. I mention it here so builders understand that I’m glad to give credit where it is due.
As you might suspect, all of the above added to the usual post-holiday return to building, and temporarily swamped our email and telephones. We were getting more than 50 emails and 50 calls a day. This stuff always arrives in a wave that leaves a new high water mark, but subsides to a normal tide shortly. If you are one of the many people who sent us a message, be assured that we are working our way through all of them.
To complete the picture, I also have to mention that such popular commentary in print always brings out the negative lurkers on the Internet. For reasons that are most probably related to emotional injuries suffered in unfortunate childhoods, there are a handful of people who cannot tolerate the successes of others, no matter how well earned the praise might be. One of my least favorite things these people do is type posts to Internet groups telling people that we are “Probably out of business” when anyone remarks that I can be difficult to reach on the phone.
Here is a test: Your best friend comes up to you and says you need anger management training. If your first reaction is to tell him to shut his pie hole and mind his own business, he is probably correct. Several years ago, in the interest of becoming a better person, I attended an anger management series hosted by an acclaimed master, nationally noted for his highly successful work, particularly with veterans. The man had the demeanor of the Dali Lama, the heart rate of an Olympic marathoner, and the stoicism of a Greek philosopher. While he stared out the window, he asked me to cite something that really ticked me off, and I mentioned people making mindless negative comments on the Internet. A smile crept over his face and he casually said, “I hate those F___ heads also.”
Above, Mark Langford’s plane on our front lawn on a chilly morning. I took this photo from our front porch. Our hangar is on the right side of the photo. Behind Mark’s plane is a drainage ditch. This is the edge of our airport’s 150′ wide, 2,800′ long grass runway. When I tell people that we live on a runway, I don’t mean it metaphorically. We have lived here the past 5 years. The house is a modest size and the 2,400 square foot hangar is an older metal building, but I did work past midnight six days a week for 15 years to get to this point. It was a long odyssey with a lot of high points and a few low ones. After 22 years of daily work in this field, it initially ticks me off when a person who has never met me questions my commitment to experimental aviation. In the end, I just feel sorry for such a person because they don’t understand having a calling in their life that they devote themselves to without reservation.
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While it is never going to stop people from typing messages about being out of business, let me review a few things for people who have not yet met us: There are a lot of good reasons why I am not ever going out of business.
1) I have been doing this for 22 years, and we are well known and respected in industry circles.
2) We don’t have any business loans nor any partners or creditors. We are not looking for, nor would we accept, any investors. We have all the money we need.
3) We operate a thrifty and simple life. I can, have, and continue to be easily capable of running the Corvair movement while deficit spending for months, and even years at a time. I have very specific non-monetary goals in experimental aviation, such as having 500 builders who have each flown more than 250 hours. I have been and remain willing to expend our resources to achieve these goals.
4) I have never been sued, named in a suit, or seriously threatened. I have been the most vocal advocate of making people aware of the risks involved in experimental aviation. This insulates us from frivolous or harassing action. Additionally, we enjoy the support of a number of highly accomplished corporate lawyers in our family, starting with my older sister. From childhood, my siblings and I were trained to be mutually supporting without reservation. This now extends to our spouses. My sister is glad to defend us for nothing.
5) I have first class heath and disability insurance. I have just had an extensive screening and have been found to be in outstanding health. I have never smoked and I gave up drinking years ago. My father is 85 and going strong. I am 48 and have every reason to believe I will live as long.
6) Although I am a pilot and an avid motorcyclist, I am well trained, experienced, and well beyond the point of taking stupid or unnecessary risks in life. When it comes to things that have killed countless pilots – showing off, get-there-itis, and peer pressure – I am immune.
7) I have known my wife since 1991, we have been together since 1999, and married since 2005. She loves me despite my faults. My work will never be interrupted by divorce.
8) I am not self destructive; I don’t gamble at all, take drugs or medications of any kind. I never ride without a helmet, and usually fly in a fire suit. I do not argue with drunk rednecks, wrestle alligators, spray imron paint, or mock 300 pound bikers who can’t kickstart their shovelheads. At 48, I can no longer die young nor leave a good looking corpse. I am now resolved to live a long time.
9) While my work is not all fun, it is very rewarding. In 2000, I was lured into a certified aviation day job by a paycheck that was six times more than what Corvair work was generating. In a few months I returned to full-time Corvair work, because my need to do something important and creative was greater than my desire for comfort and consumer goods. We have made countless friends from a collection of the finest people you could hope to meet. When I was younger, I would have been depressed to think that my life’s work would largely fall into one area. Today, I actually consider it something of a privilege that through persistent hard work and the support of family and friends, I can actually focus my efforts on a single front and see how far I can advance the experience of building and flying.
These are the nine factors that tell everyone in the Corvair movement that I am in it for the long haul. Anyone who suggests otherwise has an axe to grind or should read the paragraphs above a few times. If you are on an Internet list and anyone suggests that the fact I don’t answer email the day it arrives means I am no longer in business, please cut and paste the above paragraph to your group. -ww
Builders,
Above, the 601XL of Woody Harris. It has flown all over the country on a 2,850. Note that Woody is from northern California and the photo above is at Kitty Hawk NC.
For our friends out west, Woody Harris, “our man on the west coast”, Called today to say that he flew from Vacaville CA to the Copper state fly-in in AZ, by way of Big Bear. He was airborne about 7 hours on an uneventful but scenic flight. You can read more about woody by clicking on this link:
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Woody had his first forum on Corvairs today, but he will be on hand this weekend to answer any question on our work with Corvairs. We keep him equipped with manuals and DVD’s for sale at events that we can’t get onto our own calendar. If you have not had a chance to meet him, look him up, he is friendly, knowledgeable, and good company. -ww.
Builders:
A few nights ago, the counter on this website went over 300,000. Not bad for a very specific subject matter and 22 months of stories. The company that provides the software just updated it so I can now tell how many different email addresses (but not which specific ones) read the site in a day. Yesterday set the one day page read high score at 1,622. This came from 677 different email addresses. Part of this was people reading the links to older stories more than once. On a typical day we have about 1,000 page reads from 550-600 different email addresses. While almost all of these people are aviators, a number of them are probably not yet Corvair builders, just people reading popular commentaries, like the one on Cessna’s throwing in the towel on the C-162. By comparing readership on those stories with the levels on pure tech. posts, I would guess that we have 400-450 Corvair builders that read the website nearly every day.
The total count on stories is now about 370. If you take out the Mail Sack, and some of the things like College notices, the three stories about our Dog, the pure building philosophy stories and my bitching about people who drive while texting on cell phones, the president of the EAA and Chinese parts, you still have at least 225 hard core technical posts and informative pieces, that will remain quality information for a long time.
.As always, I encourage anyone to write in with a comment to write it in. We are always glad to share the perspectives of builders, their experience and photos. For now, I am headed back out to the hangar to make a few more things to get in the mail tomorrow.-ww.
Builders,
A friend of ours who is building a Zenith 750 wrote in with a quick note asking about oil pressure gauges and senders. I pulled together this general set of notes on oil pressure measurement and instruments as a good resource on the general subject. Over the years Corvairs have flown with just about every kind of oil pressure instrumentation imaginable. Going back to my point of Principle vs Preference. On this subject, it mostly falls in the category of preference.
The Builders specific question was focused on sending units for electrical gauges, and their reliability. If I had to pick one brand over another, I will say that I have never had an issue with the senders that are used in Autometer gauges. VDO is usually trouble free, but I have personally had one mess up, and it caused a lot of work with it’s erroneous information. Goes without saying, I wouldn’t use one from the land of Chairman Mao.
Some people are concerned about mechanical gauges bringing oil into the cockpit, but in actual experience, I have never had an issue with it. The line itself is 1/8″ on the outside, but only 1/16″ on the inside, and I generally put a #80 hole in a restrictor, at the engine, so even if the line came off, the flow rate is about 1/2 gallon per hour. For the record, I have never seen even the poorest mechanical line installations leak. You can take the nut off at the gauge with the motor running, and it does not “spray” oil, it just oozes, and even when the engine is hot, the oil really isn’t after six feet of line.
Below is the close up of the mechanical oil pressure gauge I have in the Wagabond. In addition to all the other things I like about mechanical gauges, I like the fact the needle covers a 300 degree arc, allowing you to see very fine changes. The gauge below is $54.97 from summit racing.
Now get a look at the next part, which is an analog electrical gauge. My primary complaint beyond the fact it is electrical is that this type of gauge is only a 90 degree sweep, making small differences had to see. They also cost about twice as much as mechanical after you get the sending unit. It is priced at $69.97, but the sender is about $40. I buy Autometer because of the tiny letters at the bottom of the instrument that say “made in USA”
For Builders interested in digital instrumentation, Google the name “Dakota Digital”. Below is one of their instruments, but the come in many different varieties, all made in the USA. They have a website you can buy direct from, it has many choices. Just a reminder, never mention to anyone on the phone while ordering from a non aviation company that you are building a plane. Summit will actually black list you. The people answering the phone have $9/hr. jobs, so don’t jeopardize anyone’s just scraping by living by saying that on the phone, and having them get in hot water for not turning you in. It is an annoying fact of a litigious society, but you are not going to fix it by getting a single mother just above the poverty line fired.
If you would like to read a two part story about the simple panel I built for the Wagabond, get a look at these two following links:
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If you would like to read a story about Andy Elliott PhD arguing with ww the A&P about instrument choices, look at this one:
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The story below has comments on oil pressure errors in electronic instrumentation. That part is 2/3rds of the way down at the picture of the Corvair/701.
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As you are looking at parts of the oil system, I have reprinted the numbering system of the parts in the oil system for reference here:
Rear oil case group (2000)
2001- Rear oil case casting
2002- Rear oil seal
2003- 5/16 hold down hardware
2004- 3/8 hold down hardware
2005- Case to block gasket
2006- Harmonic balancer
2007- Balancer bolt and washer
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Oil pump and regulator group (2100)
2101- Oil pump assembly
2102- Oil pump gaskets
2103- Oil pressure regulator piston
2104- Oil pressure regulator spring
2105- Oil pressure regulator plug
2106- Plug washer
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Below is a good article of flight ops with comments on oil pressure indications:
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Below is a short guide on what oil to use:
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Below is a visual reference to where we take the oil pressure on the Corvair engine:
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Below has notes on how the pressure bypass works:
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Have a pleasant and productive evening.-ww
Builders,
3,000cc PC Cruiser builder and Aeronautical Engineer Sarah Ashmore shared the following press release:
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“Cessna President and CEO Scott Ernest is signaling that Skycatcher, the company’s low-cost, Chinese-built light-sport aircraft, has been relegated to the history books. “There’s no future,” Ernest said when asked about the aircraft at a Cessna press conference Oct. 21 at the NBAA convention in Las Vegas. Asked if that meant the project would be discontinued, he replied, “No future.” Skycatcher was launched six years ago with great fanfare by Ernest’s predecessor, Jack Pelton. Offered at an introductory price of $109,500, the aircraft attracted 720 orders worth more than $75 million in the first three weeks after launch, and backlog ultimately topped 1,000. But the project was bedeviled by manufacturing problems at its Chinese partner. Cessna also was forced to raise Skycatcher’s price, which caused its backlog to evaporate. Ernest was more upbeat on two new signature projects at the aircraft builder. The Citation Latitude mid-sized jet is on track to make its inaugural flight in the first quarter of 2014, and the Citation X — billed at the “world’s fastest civilian aircraft” — is expected to win final certification in March.”
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In with a big bang and out with a whimper, thus ends Cessna’s 162 Skycatcher, an aircraft that was promised to set great standards in general aviation, ends up never even getting to heavy production in spite of having 1,000 deposits.
Note that the reason for the failure is: “the project was bedeviled by manufacturing problems at its Chinese partner” . Where is all that Chinese workmanship and craftsmanship now? Please note that this project, specifically shipping it to China, was the brainchild of the former CEO Jack Pelton. In case you are wondering what that guy does for a living today, why of course he is head of the EAA. Does he sound like the person who really has his finger on the pulse of General Aviation? Really understood traditional American aviation values? Absolutely not. Pelton was willing to sell out all the craftsmen who worked in Wichita for cheap Chinese labor if it could make a buck. If you work for a living, and you are an EAA member, you need no further proof that if there is a corporate dollar to be made, your interests, skills, support of our organization, and your respect for your fellow working Americans mean nothing to him.
So Cessna finds out that they should have had these planes made in the USA. The corporate elite will blame the 2008 economy, but it is fair to ask what part of our economic troubles and slow comeback belongs to all the CEO’s like Pelton who shipped our manufacturing base overseas for their own profit. (These are the people who can’t understand why a guy who had his skilled craftsman job outsourced in 2005 and now works in a $7/hr service job finds taking his family to Oshkosh unaffordable.)
And let us not forget the 1,000 wealthy buyers who certainly didn’t care where their new $100K toy was made, as long as they got to have it. We are all forced at times to purchase some imported things from places we don’t like, but a person who can buy a $100,000 toy with discretionary income isn’t forced to do anything. If you buy a pair of imported sneakers once a year, you are not giving away the same jobs nor fueling the trade deficit like a guy buying a Skycatcher. I am sure plenty of these 1,000 eagerly awaited delivery while driving around in imported cars with “take back America” stickers on them. If they don’t care that their imported Cessna would be built by $2/hr labor in a police state while the unemployment lines in Wichita got longer, then where do they draw the line? If Jack Pelton had struck a deal with Bin Laden’s family to make Skycatchers at the family run IED plant in Pakistan, I am sure that 50% of the ‘patriotic’ 1,000 buyers would have asked “can I still get my Skycatcher this year at the same price?”
If I seem to be harsh on this, it might just be that you missed my long standing and vocal hatred of the C-162. When the plane lost both the prototypes in spins that Professional test pilots could not recover them from, I was glad to question if this plane was right for student pilots; When the EAA accepted samples to fly young air academy students in, I was among those that said you can’t tell a 15 year old to study and become an engineer if you show him a plane built elsewhere, and tell him he will never have a job producing them; I have pointed out countless times that there is no such thing as Chinese business ethics and quality control when it comes to making cheap things for export.
So, who will make America’s light planes? You will, the working American, just as you have always done. In 1946 Cessna went from war production to making 30 C-120’s and C-140’s a day, without any issue at all. The greedy corporate scum like Pelton had 6 years to tool up and they couldn’t hardly make 30 aircraft per year in China. The only important difference is that the Cessna ownership in 1946 respected their workforce of Americans, and 60 years later Pelton had all his faith in the best $2/hr Chinese workers he could buy. Moving forward, it is clear that Cessna has now abandoned the “affordable” aircraft market. This makes no difference to any homebuilder. In 1946, Cessna was something of a partner to American labor in producing that generation of affordable American aircraft. Today, they have proven to be a worthless element. Each of us, developing our own craftsmanship, will work in our own one plane factory and produce our own aircraft. This is how American labor will build this generation of affordable aircraft. We don’t need cheap labor in China, we don’t need greedy CEO’s and we don’t need any membership organization that is headed by a person who fails to understand this.-ww.
Builders,
Here is your last official notice on CC#27. While the frequency of notices resembles a PBS fund drive, I want to say that we always have one or two people who miss the notice and sometimes the dead line. Don’t let this happen to you. If you are sitting on the fence, we are getting to the wire. The sign up for #27 has been open for 100 days: you now have less than one day left to sign up. Click on this link for more info:
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Builders,
Here is some very detailed flight data from 2,850cc Zenith builder/flyer Jeff Cochran. It is a very good and useful piece of data collection, with many fine points included. I took more than an hour to examine the charts in detail. Jeff’s accompanying letter had a lot of good flyer feedback in it also. He is straight forward and methodical in his evaluation to fine tune his specific installation. I share with builders some larger perspective to put this data in a context where you may find it easier to appreciate.
Jeff and his lovely wife at CC#16. They have attended many colleges. Jeff ran his engine at CC#19, and will likely flying it back to CC#27 for it’s public debut in front of fellow builders who fully understand the achievement of completing and flying your own plane.
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For a little background on Jeff and his plane, read the story by clicking on this link:
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One of the things that came to mind when looking at Jeff’s data was the early work that Mark Langford did in data recording in his KR-2S. (Mark was the first pilot to be awarded The Cherry Grove Trophy in 2008) Eight years ago Mark was one of the first guys to publish this kind of information from his Grand Rapids unit. It was read by many builders, and was a unique resource and sparked a lot of discussion, and also squashed a lot of pet theories among the internet armchair opinion crowd. Let me use the photo below to illustrate an interesting distinction between the data sets:
Above is Mark Langford’s plane with the cowl off in a photo from Corvair College #16. The airframe and the engine installation were unique in many ways. The plane was built as a personal expression of his creativity. Several other KR’s followed Mark’s build and utilized ideas that worked on his plane. Since this segment is focused on CHT, look at Mark’s cooling, a twin ‘plenum’ style system that worked well in his plane. His cowling was one he made a mold for, he used a rear starter and belt driven rear alternator, along with a remote cooler. These ideas served him for more than 1,000 flight hours in his KR, however some of these ideas would have limited applicability on other airframes. The 5th bearing on this plane is the same design I am using on our Wagabond, but almost all of the other subsystems on the Wagabond are common to our standard 601/750 installation. The Kr is a small fast aircraft that operates in a different flight envelope.
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What makes Jeff’s data unique to me is that it is all gathered around off the shelf parts on a very popular airframe. KR airframes are highly individual. The have a choice of airfoils, wing areas and spans, different landing gear, fuselage lengths and widths, and several canopy styles. By comparison, no such variation exists with Zeniths. What one builder learns can be directly applied to another’s aircraft with predictable result. Virtually all Corvair/750 builders utilize standard parts from our catalog, and assemble them according to our installation manual. Additionally, a 750 is the largest and slowest climbing aircraft Corvairs are commonly used on. One can be reasonably sure that anything that works in a Corvair/750 aircraft cooling/cowling system will also work on any faster smaller Corvair powered airframe, whereas the reverse is not frequently true.
In Jeff’s letter he references comparing notes with Gary Burdett. If you have not seen it, we have pictures on this site and his story is at this link: Zenith 750 Flying on Corvair Power, Gary Burdett, Illinois . Because their two airframes and engine configurations are very close to each other, They can utilize shared information to fine tune each of their planes. This goes further than just having a cowling in common. Details like both aircraft having a gold oil filter housing means that data like oil temp is taken at the same spot on both engines, giving very direct comparisons.
This effect is true for all Corvair/Zenith combinations to a degree that is not possible with individualized aircraft like KRs and to a large extent, Pietenpols. Both of those airframes have active and well run internet groups. Zenith runs it own gigantic webgroup for all of its builders. To give builders working with the Zenith/Corvair combination a specific spot where they could directly exchange data and notes, we set up a specific discussion board just for them. You can read about it by clicking on this link: ‘Zenvair’ Information board formed . The quality of discussion there is very high for several reasons. It is an invitation only group and it is very effectively organized and moderated By Phil Maxson. You can read about phil at this link: Guest writer: Phil Maxson, flying a 3100cc Corvair in his 601XL. Jeff, Gary, Phil and other ‘Zenvair’ builders can directly work with each other in a setting where everyone is a serious builder.
The two links below are the Data that Jeff refers to in his letter. Interesting to have independent confirmation and data to say that the alternator location doesn’t make much of a difference in cooling. We sell the front alternator (group 2900) and Dan sells the rear alternator (Group 2950). For many years people speculated that moving the alternator to the back would cause a huge reduction in temps. Both Dan and I told people this wasn’t likely because non-plenum cooling systems with round inlets are very good about sharing all the incoming air no mater which hole it arrives through. Jeff’s numbers confirm this and show the limitations of ‘eyeball & theory’ vs accurate back to back testing.
Many people who have never met me picture me as an opinionated zealot advocating some type of ‘my way or the highway’ mentality, unable to change perspectives. While I do have principles that I will not compromise on, 25 years of working on planes has given me the perspective to understand what is an issue of principle and what is just a matter of preference.
Many closed minded people act like zealots simply because they don’t have the experience to differentiate between these two. Picture the guy who frequently says “That will never work”; He is proven wrong by the first guy who makes a trip around the pattern with the idea. Conversely, when a guy says ” might work, but I prefer not to do it that way because….” he is speaking from experience. On matters of preference, I am open minded. I have a 5th bearing design and sell front alternators, but our production engines feature Dan bearings and mostly rear alternators. I assembled both Jeff’s and Gary’s engines. They are very similar 2,850s yet one has a Dan bearing and one has a Roy bearing. These are all matters of preference between proven parts. I am if favor of builders making educated choices. The operative word ‘educated’ starts with real data like Jeff is presenting here. -ww.
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Jeff’s data charts:
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Jeff’s Letter:
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“William, Since you are doing all of the CHT and cooling articles, I thought I might update you on my progress.
I have dropped the bottom of the cowl so that I have almost 4″ between the bottom edge of the firewall and the bend in the cowl bottom. By my calculations this gives me a 2.4 to 1 ratio. I still want to up this a little. This is very close to the set-up Gary Burdett is running. We should be almost exactly alike now with one or two exceptions. I went ahead and ordered and installed the rear alternator kit from Dan. The front bracket is still in place just in case I need to go back. I am also flying without the leading edge slats. My inlets are 5″ and still raw cut edges with no ring inlets.
Sensor set-up has been changed. For a while I ran a thermocouple in each of the thermowells like the GM thermistors and a 10mm ring on the thermocouple bolt. I also had a 14mm ring on the corresponding plugs. So three sensors on cylinders 1 and 6. The plug was always the highest, the bolt the lowest with the thermowell location in the middle. I discontinued the two bolt locations and moved those sensors to plugs 2 and 3. Somewhere I had heard that cylinder 3 was always the hottest, but my data really does not support that as far as the plugs are concerned.
My Dynon D180 saves data on almost every possible parameter you can attach a sensor for. I download the file after every test flight. The first page of the attached workbook is the total raw data. On the second page I delete all of the data that is not really recorded (the Dynon seems to make up data when no sensors are attached). Then on the short version, I delete everything I am not interested in at this time. I chart the CHT’s and since the alternator move the electrical data. I have attached the excel workbook file. But just in case you really are the computer troglodyte you claim to be (which I really doubt) I have converted the CHT chart to .pdf.
The alternator move as you have often said did not seem to make much difference in cooling. Logically that was so hard to believe I just had to prove it to myself, You probably have realized by now that some of us are hardheaded that way. Cylinder 6 is always much cooler that cylinder 1 so I tend to concentrate on cylinder 1 numbers. Since the 380 degree number has been posted by you and I have seen it on the car sites also, I set my goal of try to keep the temp measured in the cylinder 1 thermowell (where the car was measured) as my normal max goal. My current set-up has been achieving that limit. I still plan to smooth and ring the inlet some time in the future.
I’m still planning to fly to Barnwell (weather permitting). Either way, see you there. –Jeff”
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
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:
“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:
“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.”
Builders:
We have a shade over 48 hours until we close the registration on CC#27 which will be held in Barnwell SC November 8-10.
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The Event also has it’s own Face Book Page:
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Below is a link to a story I wrote about the specific skills builders learn at colleges. Read it and decide if you would rather learn these things slowly at home, or head to the college and have me teach them to you personally in one weekend. You can do it either way, but I an assure you that it changes the way you see yourself, from mere owner to builder and master of your Corvair engine to know these skills. It is hard to make an argument against learning them sooner rather than later.
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Below is a link to my story about the “Cherry Grove Trophy”, which we present to the outstanding Corvair Aviator of the year each November. In 20 days there will be a new name on the Trophy, and a fresh presentation made at Saturday night’s dinner. In other branches of aviation, the awards often go to the guy that wrote the biggest check or had the most political influence. In the land of Corvairs, we are not polluted by corruption like that. Our Trophy goes directly to the individual that set an outstanding example and gave back to others now building. Barnwell is the setting where you can meet these builders in person and understand that your place is beside them, In the Arena. Reading a membership magazine featuring aircraft no working man can afford, written by editors who would consign and condem you to be only a spectator is the antithesis of this. Read this story, contrast it to most industry magazines, and then decide for yourself: Spectator or Man in the Arena?
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Blast from the past, CC#19, Barnwell, 2010. Builder Jeff Cochran stands with his running Corvair. Today this engine is flying in his Zenith 750. He is planning on flying it back to Barnwell for CC#27. Progress is made by deciding that the time has come to advance your own dreams. You must choose this, it doesn’t happen without your personal action. If I am ever going to write your story about flying your plane, you must take action to start this.
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” (2010)- Zenith 750 builder Jeff Cochran of Alabama supervises the run-in of his 2850cc Corvair, above. The Zenith 750 is a large airplane capable of climbing at very low airspeeds. This combination makes it brutally unforgiving on engines with inadequate cooling or light duty construction. The Corvair’s outstanding cooling and high quality components make it impervious to installations that are the undoing of lighter engines.”
