Basic Corvair Information

Here as a basic briefing on Corvair flight engines for builders getting a first look at using one.

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Above, A  3,000 cc Corvair flight engine. I built this particular one in 2012 for the SPA Panther aerobatic aircraft prototype.  The Corvair is a popular option on more than 20 different experimental airframes.

The Corvair is a General Motors designed engine, manufactured by Chevrolet.  1.8 million engines were built in the Tonawanda New York engine plant between 1960 and 1969. The Corvair has been flying on experimental aircraft since 1960, and I have been working with them as flight engines since 1989. It is a story of careful development and testing, a slow evolution to the engines we have today. It is ‘old and proven’ rather than ‘new and exciting.’

Configuration:  The engine is a horizontally opposed, air-cooled, six cylinder configuration. We only promote its use as a simple, direct drive power plant. The engine configuration is very similar to Lycomings and Continentals.

Displacement: The engine is effective without a gearbox or belt drive because it has a comparatively large displacement. Between myself and SPA, we have versions that are 2,700, 2,775,  2,850, 3,000 and 3,300 cc. The smallest of these has twice the displacement of a Rotax 912.

Power: Corvairs have several different power ratings. 100, 105, 110, 120 and 125+hp. These correspond to the five displacements listed above. They make their rated power at 3,150 rpm. They have wide power bands, making 75% power at 2,650 rpm. All engines will exceed their rated power at higher rpm, and they can be continuously run at full power at 3,400 rpm without damage.

Weight: The engine weighs 225-235 pounds ready to run. This is effectively the same as a Viking 130 and slightly less than a Continental O-200. It’s installed weight is 35 pounds more than a 912 Rotax, 25 pounds more than a Jabaru 3300. The Corvair is 40 pounds lighter than a Lycoming O-235. Larger Corvairs are slightly lighter because they have special cylinders made for them which make these engine lighter.

Reliability: From the factory, the Corvair made up to 180 HP in the car and turned more than 5,500 rpm. The engine is reliable and long-lasting because we are only operating at 60% of these levels. Conversion engines that run at the car’s red line rpm historically have short lives and cooling issues.

Cost: We sell complete engines from $12,750 to $17,750. However, 90% of our builders assemble their own engines working from our Conversion manual, DVDs, parts and support and a rebuildable core engine they pick up locally. Typically, they budget $8,500-10,500 to build a first class, zero timed, engine. Budget motors can be built for as little as $6,500.

Cooling: The Corvair has a factory cylinder head temp limit of 575F. This is the highest limit on any mass-produced air-cooled engine ever built. The engine as also the first mass-produced turbocharged car. GM engineered the motor to have excellent heat tolerance and heat dissipation. In aircraft the engine typically runs at 325 to 350 CHT.

Parts availability: Every wearing part in the engine has continuously been in production for 5 decades. The engine pictured above, only has an original pair of cases, and oil housing and cylinder head castings. All other parts in the engine, including the crankshaft, are brand new. Many of the parts in the engine, like the lifters and valve train, are common to Chevy v-8s. There is no part availability issue.

Ignition: The fleet of flying Corvairs is about 500 aircraft. More than 90% of them have a dual ignition system that I have built. Our system uses two redundant systems, one points based, the other a digital electronic system. The design has two of every part potentially subject to failure, but it utilizes one plug per cylinder. Six cylinder engines can fly on one cold cylinder, most 4 cylinder engines can not. We have dyne proven that a Corvair running on 5 cylinders will still make 78-80% power. Plug fouling is unknown in Corvairs because the ignition system is 40,000 volts and uses a plug gap twice as wide as a magneto system.

Fuel: The Corvair can use either 100LL or automotive fuel. It is not bothered by ethanol in the fuel.When Corvairs were designed, car gas was a lot like 100LL; for the last 35 years every mile driven by Corvair cars was done on unleaded car gas. Many engines like 912s and modern car engines do not have exhaust valves that can withstand the corrosive nature of 100LL. We use stainless and Inconel valves in Corvairs with rotators on the exhausts.

Maintenance: The Covair is low maintenance. The heads never need retorquing. The valves have hydraulic lifters and never need to be reset or adjusted. I dislike the term “maintenance free”, because it implies a “no user serviceable parts inside” disposable appliance mentality, but the Corvair is a solid, robust, machine which holds its adjustments, but our program is aimed at teaching builders to be self-reliant owners.

Goals: If one of your goals is to be the master of your engine and airframe, the Corvair is an excellent choice. There are many engine options for people who just want to buy something. Our efforts are aimed at expanding the personal knowledge and skills of each builder.

Made in the USA: In an era where everything seems imported and companies like Continental have been sold to the Chinese Government, We have kept the “Made in the USA” option for builders who prefer to employ fellow Americans. Virtually every part in the engine, with small exceptions like the distributor cap (made in Mexico), are made by American craftsmen. Because we also sell engines outside the US, we are a Net Exporter, helping correct the trade imbalance.

Corvairs have proven themselves to serve a very broad variety of builders. Many alternative engine options are offered only as a complete import, more of an appliance than a machine, with little or no consideration of the builders, skills goals, needs, budget or time line. The Corvair has options to address these valid considerations, because your power plant should conform to you, not the other way around.

This said, Corvairs are not for everyone.  In the 31 years I have been in the EAA and working with builders, the Corvair has always been very popular with ‘traditional homebuilders’, the people who have come to experimental aviation to discover how much they can learn, understand and master.  The expansion of the EAA has brought more of these builders, but it has also brought a great wave of people, incapable of distinguishing between mastery of an aircraft or an engine and just merely being its buyer and owner.  People who’s consumer mentality and short attention spans are better suited to toy ownership than mastery of skills and tools in aviation. Corvairs, and perhaps experimental aviation, are a poor match for such people. Many salesmen in our field will gladly sell anything to anyone with green money. I am an aviator, not a salesman, and the gravity of the subject requires more frank discussion and ethics than many salesmen bring to the table.

If you came to experimental aviation to find out how much you can master, not how little, then you are among the aviators who follow Lindbergh’s timeless 1927 quote: “Science, freedom, beauty, adventure: what more could you ask of life? Aviation combined all the elements I loved.”  Even if you are brand new to aviation, I am glad to work with you. I have a long history of working with builders of all skill levels. We have a number of successful builders out flying who are the masters of both their airframes and engines, who had never changed the oil in a car before building their plane.  If you got into experimental aviation just to buy stuff, then any salesman will do just fine for you. If you got into experimental aviation to learn, develop your own skills and craftsmanship and make things with your own hands, then who you work with really matters. You can’t become and old school homebuilder / motor head by buying things from salesmen. They have nothing to teach you. What you will do in experimental aviation is not limited by what you already know. It is only limited by what you are willing to learn, and selecting experienced people to learn from.  If you are here to learn, I am here to teach. It is that simple.

William Wynne

Investing in American Jobs.

Builders

Yesterday I drove 100 miles to an aerospace machine shop I have worked with for 20 years. The picture below are the parts I received, arranged on my living room floor. While the great majority of experimental engines are made of imported parts, and a lot of it from China, The stuff I sell has always been, and will always be, Made in America. 

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Pictured above, 13 #2501-B Short Gold Prop Hubs, 25 #2601-S Standard Gold Oil Filter Housings, and on the right upper side, are 6 #2601-R Housings, the mirror image models we use on Sonex and Waiex airframes. There are 24 High Volume Oil Pump housings, these go into #HV-2000 rear old cases. This is roughly $20,000 in inventory. It is just four of the part numbers in my catalog which has more than 70 items in it. I have the motor mount tubing kits CNC machined in Canada from US tubing, and I have two small subcomponents which are made in Mexico, and I do sell Rotec carbs, which are from Australia. These are small exceptions. 

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Yesterday, when I went through the CNC shop, they were operating at full employment. I stopped to look at one of the machinist’s personal tool boxes. In the top cover was several pictures of him, his wife and three kids. When you buy a part from me, you are directly making sure that guy has a job, and has a stable home for his family. I could have any of the items in my catalog made cheaper in China, and who knows, they might actually work, but I’m not going to find out. If  someone can’t design affordable parts, which are a good value for builders, even when the fair cost of American labor is included, they are lazy, greedy, or both. 

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It’s an election year, and friends and neighbors will prove that the right to fee speech doesn’t require the speaker to have anything intelligent to say.  Perhaps the dumbest things said is commentary on what is wrong with America, coming out of the mouths of people who try to defend their compulsive need to buy imported things. Personally, I think of China as the largest Police State the world has ever seen, without civil nor human rights. I regard anyone who profits from sending them our manufacturing jobs or defends their “culture” in the same light as I would regard anyone who advocated investing in 1937 Germany.  Your life, your money, your ethics. Not important to most people, Very important to some people. 

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The median age of the very poor in Florida may be as low as 12 years old. You can’t wave a magic wand and make that go away, but if you want to attack it, you do something that provides a good job for that kid’s parents, preferably in manufacturing. You don’t need a PhD is sociology to understand that domestic violence and substance abuse go down when employment goes up. People say the family is the fundamental element in the country, and I agree, but a family where people can’t work, take care of themselves and have basic dignity is a disfunctional family, and your fellow countrymen deserve a better shot in life than that.   Employment is a moral issue. There is no discretionary consumer good I need enough for a 12-year-old American to go hungry so I can save a buck on it.” – ww. 2016

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ww.

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Carb Ice

Carb Ice
By Grace Ellen

 

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Grace Ellen is a freelance writer and pilot. She was a newspaper journalist for 10 years but left the profession upon finally conceding that it was morally bankrupt. A three-day open cockpit trip home from AirVenture 2001 in N1777W crystallized her love of aviation and formal training followed in a 1943 Taylorcraft L2-M. Tutored by CFIIs Chuck Nelson and Ken Terry, she also received aerobatic training. Grace Ellen earned her IAC Smooth Patch flying Ken’s Christen Eagle. A member of local IAC and EAA chapters, she is close to completing her instrument and commercial ratings. MCM

William Wynne was the passenger in his Corvair powered Pietenpol when it crashed north of Tampa, Florida, on July 14, 2001. The engine cut off at 700′ AGL, which gave only 60 seconds to attempt a restart and execute a forced landing. To avoid people on the ground, the pilot tried a sharp bank and the plane spun in from 80′. The impact destroyed the airframe.

When freeing the trapped pilot, a fire started and ignited William’s fuel-soaked clothes. While extensively burned, both William and the pilot survived the accident. An investigation into the engine stoppage has indicated that carb ice  almost certainly was the cause. Because a few of the engine components were incinerated in the fire, no one will ever be able to say with 100% certainty that carb ice was the cause. The engine was recovered from a wrecking yard where it sat for months, placed on a test stand, and runs well. The remaining wreckage was examined very closely and no evidence of any kind of failure was found.

This mechanical integrity and clues such as visible condensation on the exposed intake manifold just prior to the engine quitting leaves carb ice as the only probable cause fitting not most, but all of the evidence, William said.

A single incident of carb ice hardly seems newsworthy. Most pilots and flight instructors feel they have an adequate knowledge of the subject. However, William’s extensive discussions with pilots and builders after the accident revealed that most traditionally trained pilots have little understanding of the subject. The rote memorization of a technique that works on a single aircraft and atmospheric setting does not constitute an adequate understanding of the topic. Further, experimental aircraft may have quite different engine management requirements.

The day of the accident was overcast with the cloud base at 800′ and dropping. The OAT was about 70F. The dew point was within 5 degrees. The trip had been 90 miles and the flight was within 2 miles of the destination. The plane had been throttled back to 60mph to allow traffic at the destination to clear. The carb heat control was in the rear cockpit and was not applied.

The engine, a direct drive Corvair fed by a Stromberg carb from a C-85, was  turning about 2,200rpm. It had at least 13 gallons of 100LL in the wing tank. Within one minute of the power reduction, the engine quit, William said.  It had dual ignition and a restart was attempted on each one. The engine  cranked normally, but did not light. Carb heat was not used. The impact broke  up the airframe and severed the 3/8″ fuel lines to the wing tank.

The  airframe ignited about a minute later when fumes from the spilling lines  reached a shorting wire. The fire burned for more than 20 minutes, consuming  most of the airframe but leaving the engine largely intact.

Many pilots interviewed later expressed the following thoughts:
1) Carb ice cannot form at 70F, and certainly not in Florida.
2) It would take longer than a minute for ice to block off the 34mm venturi.
3) The engine would “run rough” for a while before quitting.
4) Ice could not form at 2,200rpm.
5) Auto fuel would have about the same potential to ice as 100LL.

All five of the above thoughts are wrong. If you believe any of them,
you are a giant step closer to having your own version of William’s accident.
Here’s why:

1) Ice can form on warm days. Anytime a gas expands from high pressure to  low it will consume energy from its environment. In this case, the gas is the  air the engine is consuming and the pressure drop is from ambient to manifold  pressure, about 30″map to 12″map. The energy it consumes is ancarbicey form of     available heat. Most of the heat comes out of the air. This temperature drop  is instantaneous and can easily be more than 40F. Shoot a thermometer with a  CO2 extinguisher and learn.

 

 

 

2) Carb ice forms at the pressure drop point, which occurs at the
restriction to flow. At a reduced power setting, the throttle plate is the
restriction, not the venturi. At 2,200rpm and 12″map, the throttle plate is
barely cracked open. Right at this crack is the idle fuel port, a tiny hole.
A minute film of ice could cover it in an instant. The engine will stop
running because at power settings like these, most of its fuel comes from the idle circuit.

3) A certified four-cylinder engine of 7 to 1 compression and 190cid
swinging a 25-pound metal prop generally will sputter for a while when it is
experiencing carb ice. By contrast, a 9.5 to 1 six-cylinder 164cid engine
with a 6-pound prop will quit nearly outright. Many Lycoming pilots said
their engines gave warning. Lycoming carbs are bolted to the oil sump and
experience the onset of icing at a slower rate.

4) Icing has nothing to do with rpm; it results from the pressure drop.
Granted, an A-65 Cub with a certified prop is very unlikely to ice at
2,200rpm, but this is because 2,200rpm usually is associated with nearly open
throttle on this plane, and consequently very little pressure drop in the
carb.  However, any motor experiencing a large pressure drop in the carb is prone to ice, regardless of rpm. The motor in N1777W had a static rpm of 2,650. Any motor that has a prop that will allow a similarly high static rpm will be running low map at an rpm like 2,200. A manifold pressure gauge provides
useful information that a tachometer by itself does not.

5) Although auto fuel was not being used the day of the accident, pilots
need to understand how it can contribute to carb icing. Remember that at a
reduced power setting, the restriction is the throttle plate. And when
operating at reduced power, there is a large pressure drop at the plate, with
its accompanying temperature decrease. Fuel flows out of the idle port in a
mist. Misted fuel is still a liquid, not a vapor. 100LL under these
conditions remains a mist until reaching the combustion chamber. Contrast
this with auto fuel, which by design will vaporize readily under these
circumstances. It is a fact of physics that when the fuel changes from a
liquid mist to a gaseous vapor, it takes further heat from the surrounding
air. This is the cooling one feels when gas evaporates off the skin. This
additional temperature drop can produce icing when the same engine under
identical circumstances would not ice with 100LL.

In the past five years, N1777W flew with more than a dozen pilots and  logged hundreds of hours that included several very long trips. William  briefed pilots who flew the plane to use carb heat before any substantial  power reduction. The carb heat system on the plane was so effective that it  produced a 200rpm drop at idle, but still had to be employed as anti-ice, not
de-ice. The pilot involved in the accident only had about two hours in the  plane, including the final flight. Click here to view the NTSB accident report.

Although much of the physics of icing can be found in textbooks and  technical publications, William’s observations on the subject are based upon  years of work and actual flight testing. It is the nature of some to debate  anything and offer opinions extracted out of context from technical  publications. But William adamantly believes that this is a safety of flight  issue and people without flight testing experience debating esoteric details  dilutes the risk management message. William deems any commentary that  hinders the delivery of the message as amoral.

To reduce the possibility of a similar accident, William suggests that  potential pilots get a better understanding of icing, more thorough  briefings, a panel placard about when to use carb heat, and carb air  temperature gauges. William is working on a combined throttle/carb heat lever
which would move in concert and have calibrated linkages, but could be  manipulated separately for run ups. All of these are small efforts when the  price can be the destruction of aircraft and the loss of life.

Update notes to 2014 manual, 1100 – Camshaft group

Builders,

If you are the owner of a 2014 conversion manual, below are some short notes on the 1100 – Camshaft group section. I have written about these details in the last 3 years, but they are presented here in summary form, please update your manuals and notebooks accordingly:

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2017 commentary:

In the last 3 years we have sold about 150 “1100-WW cam kits”, (Group 1100 cam kits on shelf.) they also went into every complete motor I built and into all of the Weseman’s “EIB” (engine in a box) kit engines. Buying one of these gets you every part from Group 1100, but it also makes sure your thrust washer on the cam is tight. In the last 3 years I have had 7 or 8 builders come to a college thinking that I was going to be OK with them assembling a motor with a wobbly thrust washer. They were not correct. Engines at Colleges and events I host,are assembled to my standards, because it is important to make things better, not good enough.

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http://shop.flycorvair.com/product/1100-cam-shaft-kit/ is the link to the products page.

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1101- an OT-10 is still a good cam, and it works, but our dyno testing in 2016 at a professional shop confirmed that our 1100 cam was a slight edge in an aircraft motor.

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1102- in 2014, I had some tolerance for thrust washers which rotated on cams. In the time since, I have concluded that since we know how to make them tight, and they undoubtedly left the factory tight, we should always make them so now. If they are tight, it precludes any conversation about “how loose is too loose?” which is exactly what I don’t like as an attitude about building engines.

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1103- no change

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1104- Clark’s standard gears are still acceptable for use, and their timing marks remain consistently accurate. Their “fail Safe” gears were once made in the US and were billets, but they are not made here now, and they are no longer from billet material. They still work, but I pushed about 10 off cams with loose washers in the last 3 years, and they don’t grab a cam much tighter than a stock replacement gear, and they are apparently made of the same material. My preferred cam gear is the California Corvairs US made billet gear.

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1105- Some HT-817s are now made in Mexico. I have seen no quality difference, but to stay with American products our 1100ww cam kits come with Summit Racing lifters, which are made in the US.

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1106- no change

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1107- no change

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Thank you, wewjr.

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Update notes to 2014 manual, 1000 – Crankshaft group

Builders,

If you are the owner of a 2014 conversion manual, below are some short notes on the 1000 – Crankshaft group section. I have written about these details in the last 3 years, but they are presented here in summary form, please update your manuals and notebooks accordingly:

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2017 Commentary:

Three most popular cranks used in engines are 8409 Gen II, the Billet standard stroke, and the billet long stroke. All of these are from the Wesemans at SPA. Very few people take a different route than this, at a typical Corvair College today, all but one or two engines will be built around one of these three cranks.  At our  finishing schools; (Corvair Finishing School #1, Video report.) Each engine is required to have one of these three crank arrangements, because the fast pace of the work does not allow for the additional time or inspection requirements of using a crank which has not passed through the Weseman’s inspection process before the event.

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1001A – The Wesemans are the only shop I use to process GM cranks. They have been doing them for many years now, and after installing dozens of them at Colleges and in production engines, I can flatly state that they have the best process on 8409 cranks. They are not the cheapest, just the best value.

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1001B – The billet cranks were just getting into high gear in 2014, today they have long since become a very popular proven park. Countless hours of  aerobatics  have been flown on them, and they are well proven, without a failure of any kind. They are still made in the USA, to the highest standards. The original 2.94″ stock stroke which went into dozens of 3,000 cc Corvairs has now been supplemented with the longer stroke billet crank that goes in the 3.3 Liter engines. Although this sounds new, it is proven and flying, and is a regular production part: 3.3 Liter Corvair, a Smooth Power House.

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1002- no change

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1003- no change

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1004- no change

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1005- no change

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1006- no change

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1007- no change

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1008- no change

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1009- no change

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1010- In the years since 2014, I have built run and inspected several dozen engines using the Clark’s in house brand main engine bearings. This have proven to be the functional equivalent of American name brand bearings.  I have used them in sizes std, .010 and .020. They work.

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1011- The commentary on Clark’s main bearings also applies to Clark’s rod bearings.

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Thank you ,

Wewjr.

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Group 1100 cam kits on shelf.

Builders,

I just got in another round of our camshafts, and have assembled them with new made in the USA gears. We now have them on the shelf at SPA/Panther ready for delivery. They come as a complete kit, with lifters, lubricant and ZDDP oil additive, every component in Chapter 1100 of the conversion manual is included. If you are planning on assembling your bottom end in the next week or month, it would be a good idea to have one of these shipped to you. If you have been good this year, maybe someone will buy you one for Christmas, but if you are in what I call the “Bag of Coal Club” , maybe just order it for yourself:

http://shop.flycorvair.com/product/1100-cam-shaft-kit/

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Above, three cams with new gears sitting outside my shop. We now have 7 kits on the shelf. The entire assembly, including raw materials and processes, is made in the United States. To learn more about cams, read this:  1100-WW Camshaft Group .

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-ww.

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How tough are Corvair engines?

Builders,

Below, two photos of damage inside core engines from running cars (not aircraft). The top was a motor run without oil, and one with finger tight rod nuts, the bottom was run with the belt off the cooling fan.

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The damage shown in the pictures didn’t happen in a second, nor in a minute either, and the engines still ran, very poorly, but they were not locked up.

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Over the years I have seen perhaps a 1,000 core motors, and very few of them had this kind of issue, almost all of them were simply worn or tired, but still capable of running acceptably when the car was parked. The major problem that makes some core motors unusable is being stored outdoors and getting water inside. You can check this easily when looking at a core engine by making sure it rotates 360 degrees before buying it. Ones that have had water inside, will not turn.

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The examples below are from cars, but I have plenty aircraft examples also; An engine run for 11 minutes turning a prop at 2,200 rpm (about 45 hp) without any oil in it. It stopped but only did $700 in damage; The guy who’s ‘local expert’ set the timing for him, but thought the 0-8-16 timing marks were 0-3-6, so he set the timing for about 60 degrees advance, which blew out 3 head gaskets. the static rpm dropped from 2,700 to 2,000 rpm but the builder actually flew it 2 more times because he had a long paved runway at his airport; the 30,000 hr airline pilot who flew a cross country with a bad enough oil leak that the pressure went to zero, twice, and he felt comfortable adding a “quart or two” and proceeding. This doesn’t even touch on the several dozen people who damaged engines by never setting the timing, but thought they were getting away with it because their engine didn’t stop abruptly, it just tolerated the blown head gaskets and broken rings without quitting. The list is endless, but let it be said that the intelligent Corvair builder has a very robust engine to work with.

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Above, two rods from car engines; the bottom was run for more than 10 miles with no oil in it. Notice that the rod bolt and nut are still intact. The bearing melted, and took out the rod, but the motor did not stop, the driver just reported it “made a lot of noise” on the drive back home. The top one was from the shop of a “race car builder” who rebuilt the engine and it lasted long enough to leave his shop, where he claimed no further responsibility. Without question, the “race car builder” forgot to torque the rod nuts on these bolts. The driver reported it ran poorly, but he drove it around for a while that way. The piston was just jammed at the top of the bore, and the engine kept going.

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Damage tolerance isn’t a primary engine selection criterion in experimental aircraft, the way it was when the US Navy specified that it would only accept air-cooled radials for combat service in WWII. Many newer engines cease to run the first moment any small piece of material gets loose in the engine, but the Corvair has more in common with the damage tolerance of radials than it does with modern engines.

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The majority of the general public when looking at photos like these will say “I would prefer to have an engine that will never break” much the same way that children have a decided preference for unicorns despite a historic supply problem that suggests the perfect engine and the unicorn will be delivered on the same day hell freezes over.

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For people into a higher level of discussion, I can point out the design features of the Corvair that give it an extraordinary resistance to stopping when damaged. First and foremost, go look at your core engine and see that the cam and crank timing gears, the only part of the engine where a chip of metal can not be allowed to pass, live in their own part of the crankcase, and don’t share the same compartment with the rest of the parts in the case. There are many other elements, like forged components which are not brittle, and particularly being air-cooled and having no possibility of loosing coolant into the engine, etc. If you like machines, it is a very interesting study.

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Above, a core engine that came to our shop in 2005, from a person who drove their Corvair for a week with no cooling fan belt on it. Both the valve seats in the above cylinder have been beaten into the ports and broken up, yet the engine continued to run on the other bank of cylinders. Notice that neither valve head come off the stem. The rusty bits imbedded in the head are broken up valve seat.  While your engine will obviously never look like this inside, it is a very desirable characteristic of aircraft engines that they be able to sustain some damage without complete failure. The next time somebody points out to you that a Corvair engine is slightly heavier than a VW, Jabbaru or Rotax, tell them that you accept this because there are robust qualities to the Corvair that you appreciate.

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ww.

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How many Corvairs are left?

Builders,

The title of this story is a perfectly acceptable question, and one I frequently place an educated estimate on.  It doesn’t bother me, even if it is asked many times a day at Oshkosh.  I do however contrast this with the person, who walks into my booth at Oshkosh and pronounces, “There are no Corvairs left. “ or “They don’t make parts for Corvairs anymore.”

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I was just about to type “It takes a special kind of idiot to say such things in the face of demonstrable evidence otherwise” but that isn’t correct. Statements like that are not the utterances of special idiots, they are spouted by common idiots. I have actually had a guy flatly say they don’t make parts for these engines while leaning on a stack of new boxes of pistons that was 4 feet high. I pointed out to another person who said their are no engines available, the dozens of pictures on my website of recently finished Corvair powered planes, and asked him where he thought those engines came from. Ironically, no answer from the same guy who knew everything 2 minutes before.

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It has been my experience that you can’t use budget, prior experience, age, nor outlook to predict is a guy will be successful in homebuilding, however, I have noted that the guy who likes to start every conversation in homebuilding with a statement that he absolutely ‘knows’ to be true, is the guy least likely to enjoy learning, and therefore least likely to be a guy who finishes a plane. Be aware that common idiots are not just found at Oshkosh, they are at nearly every airport in the country. For a laugh, I highly suggest getting a look at this: A visit to the insane asylum .

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Above, a very heavy box in the back of my 3/4 ton truck in the front yard this morning.  It was 48″x 40″ by 40″ and packed solid with Corvair cylinder and connecting rod cores being truck shipped to Clark’s Corvairs in Massachusetts. the rear suspension is compressed about 8″.

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The box has about 50 engines worth of cylinders and rods, and these are all going back to Clark’s for reboring and rebuilding. I collect them up over time, and send them back in a large lot. Think this is a big amount? I have been to Clarks shop, and this isn’t 5% of what they have on hand, and I strongly doubt that Clark’s is holding 5% of the remaining Corvair cylinders….Oh, by the way, 2,850, 3,000 and 3.3L Corvairs are all based on new cylinders and rods, so everything in this box can be applied to 2,700cc Corvairs.

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There are probably less than 5% of the original 1.8 million Corvairs left. If that sounds small, it is 90,000 cars. We live in a nation of 250 Million registered cars. Any reasonable person can look at those numbers and understand a ratio of 2,778:1. and probably on the order of 20,000:1 in a daily driver comparison, why you don’t see a Corvair driving down your street everyday. But only the common idiot looks at those numbers, the giant box of cores, the fact I have been doing this since 1989, and Clarks has been doing Corvair parts for more than 40 years, and still is sure enough to say there are no Corvairs left.

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Automotive production numbers dwarf anything aviation has ever made: The Jabbaru 3300, the Rotax 912 and the Continental O-200 are all good engines that serve particular builders. These engines have been made for 20, 30 and 60 years respectively. Corvair were produced for just 10 years 1960-69, but consider this: They made more Corvairs in the first 10 days of production in 1960 than Jabbaru has built 3300’s in the last 20 years; To match 30 years of 912s took GM till the third week of production in 1960; To match 60 years of O-200s took the GM engine plant about 50 days in 1960. And from there GM went on to another decade of engine building. It is my educated estimate, that there are more Corvair core engines remaining in the US, than the entire combined production of 3300’s 912s and O-200s. Give that some thought the next time someone tells you there are no more Corvairs.

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-ww.

Front Alternator Belt, Part #2904, new source.

Builders:

In our conversion manual, (http://shop.flycorvair.com/product/conversion-manual/) , The front alternator group is #2900, and the belt itself is Part #2904.  In the manual we specified a Continental AVX10-710 belt. A number of people have asded about another source, as Conti, now lists their number as obsolete, and people had a hard time at their local auto parts store getting an interchange.

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The issue is that most countermen don’t know enough about the parts they sell. Conti is a German company, and the “10” in their part number is 10mm wide, and in the US that is a 25/64″ width belt. “710” is the pitch length in mm’s, which is pretty close to 28″. The belt pictured below, available from any NAPA store, is a valid interchange. Please write this note in your conversion manual.

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Above the correct replacement belt.  This has been verified to work on a Gold hub, with a Front Alternator bracket set and a front alternator.

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-ww.

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