Corvair College #10
Installation Manual Update
Again With The Internet
Corvair College #10 is approaching. The first day of the College will be Friday, Nov. 10, 2006. We'll be checking people in after 2 p.m. We'll have
a group of informal activities until 9 p.m. The first full day of the College will be Saturday, Nov. 11. The events will begin at 9 a.m. and continue
late into the evening. Saturday will be the main day. After dark we'll have a cookout, a few technical presentations, and the highlight of
the evening will be the presentation of the first Steve Jones Memorial Trophy. We'll have plenty of time to socialize late into the night. Sunday will
kick back in with more tech presentations and the running of the two demo engines. The learning and flying will continue through the afternoon.
In 10 days or so, we'll have a complete online syllabus/program available to anyone for download. We're lining up several more technical presentations.
Arnold Holmes will be on hand to demonstrate dynamic prop balancing. We've already
lined up two aircraft for demonstrations. Spencer Gould will share composite building tips as they relate to his Corvair powered SG 500 project. We're working
to have Mark from Falcon automotive on hand. As expected, the regular cast from the Hangar Gang will be on hand to answer all your
We had 9 Corvair powered aircraft on hand last year. We're shooting for 12 this year. We've heard from pilots like Joe Horton of
Pennsylvania and Phil Maxson of New Jersey who will be flying in for the first time. If you haven't yet made reservations, let me again suggest the Edgewater
Best Western, (386) 427-7101. The majority of people who've already made plans are staying here at the "Corvair College Rate," and it's an easy ride to the airport.
More info will be forthcoming in a week or so, but make plans now.
In addition to preparing for CC#10 and producing all the regular parts, there are always special projects going on. General R&D, Fifth Bearing, Turbo work and
product improvement all fall in this category. One of the projects that's been getting serious effort to finalize it in the past few weeks is the 601 Installation
Manual. These photos represent the work going into a single chapter in the Installation Manual on building and installing the cowl. Steve Upson and I are working in
the shop to make two complete perfect 601 cowls, document the process, and have a first class set of drawings made from the cowls. The aircraft in the photo is
Rick Lindstrom's 601XL which will be on hand in flying condition at the College.
The nosebowl is held in place by a 13" plywood ring. The face of the fiberglass nosebowl is 7/8" behind the face of the
Prop Hub. This will provide a uniform 3/8" gap between the 13" spinner and the nosebowl. Sheetrock screws through the fiberglass into the
plywood and two bolts through the Prop Hub hold the nosebowl in perfect position. Make sure the nosebowl is level across the centers of the air inlets.
The sheetmetal on the fuselage sides and top are trimmed back to 70mm from the rivet line. This is illustrated in the 601 plans.
A string line is stretched from the two crease lines in the fiberglass nosebowl back to the center rivet, which holds the instrument panel to the fuselage top.
In this photo, there's a straight edge lying along this line on the fuselage top.
The point where these two lines cross the firewall marks the aft width of the top cowling panel.
The top center panel is made of .025 6061-T6. The front edge is 275mm wide. The rear edge is 125mm. It has a 3/4" leg turned down on each side. This leg is
trimmed away where the panel meets the fuselage top and the fiberglass lip on the nosebowl. Clecos hold the panel in place during construction. Upon installation,
tinnerman nuts and PK screws will secure it.
The photo above shows, from left to right, the simple sheetmetal scoop that fits under the bottom panel of the cowling and functions as the carb heat box;
a K&N filter from a Yamaha motorcycle; and the mold to make the fiberglass scoop wich holds the air cleaner in place and feeds the
air to the carb inlet flange. They're sitting on top of a blank that will become a bottom cowling panel. We have flight tested these pieces for the past
year-and-a-half on our own aircraft. They've flown additional hours on the 601s of Phil Maxson and Dr. Gary Ray. The construction of these pieces will be
fully detailed in the Installation Manual. We've worked very hard to develop simple to fabricate components that work flawlessly to provide a complete installation
for 601 builders. This system is adaptable to other aircraft. We're shooting to have the Install Manual complete with its formal introduction at the College.
In the photo above, Spencer Gould with a Front Spinner Bulkhead and Crushplate. He's smiling because he did the CAD work on the aluminum part and found it
to be dead nuts on when he checked it. This unit has been a lot of work to bring to completion. The prototypes we've been flight testing have been pictured in
many photos on FlyCorvair.com. The 601 construction pages discuss the concept of the part in detail. In short, it is only needed by builders who will be using a
13" spinner in combination with a Warp Drive Propeller. A handful of people have missed this, or do not understand that spinners require
a front and rear bulkhead. Warp Drive props have thin hubs and require this unit to properly stabilize the large 13" spinner.
The raw fiberglass bulkhead as it comes out of the mold needs to be trimmed to a uniform width, as we're doing above. A cutoff wheel chucked in the 3,000 rpm
drillpress held 1" off the table with the ShopVac right behind it makes quick work of this.
Above is the view of the rear face of the unit. This is the face that touches the Warp Drive hub. The aluminum crushplate is used to spread the clamping
loads on the hub. Thus, the screws that hold the fiberglass bulkhead to the crushplate must be flush NAS screws. NAS screws have a 100 degree countersunk
head. Molded into the fiberglass is a lip that holds the bulkhead exactly concentric on the spinner. The bulkhead mold was made in a lathe to ensure it is
perfectly concentric with the lip. The holes in the aluminum crushplate for the prop bolts are a very tight .377". Standard off the shelf crushplates have
holes that are 1/32" larger in diameter than this. This is because they're designed to work with wood props. Since this unit is to solely work with Warp
Drive props which have machined aluminum hubs, we could go far tighter on the tolerance and have a much more concentric assembly. This concentricity shows up
as a far more balanced propeller assembly.
Above is the front side. The fiberglass bulkhead is trimmed away around the prop bolt holes. It is completely unacceptable to have any form of fiberglass in
compression by the prop bolts. With it trimmed away above, the prop bolts bear directly on the aluminum crushplate and clamp the Warp Drive hub to our
Prop Hub. The rear bulkhead used is the stock Van's 13" aluminum bulkhead, which is included with the spinner. The NAS screws are secured by metal locknuts on
the front side.
The Internet obviously works to improve aircraft building in many ways. You're reading this off the Net right now, and most of the people who come to College 10
will get the initial information on it from our Web site. However, just like other sources of information, the Internet has its flaws, and some of these are magnified
by the factors of immediate access and little accountability. I write the following comments as a reality check on some of the items which have appeared on discussion
groups recently. I know that the ability for us to communicate with builders rapidly far outweighs comments of others which need correction. But it has been my
experience that incorrect or incomplete information on the Net unchecked generates more speculation, builder paralysis, a lot of phone calls to us. I don't mind
the last one. I am far more bothered by discovering a builder who spent months going down a dead end suggested buy a Net source, all time and money leading him away
from completing his plane. My only goal is to share what we have proven to work in this specific application, and have builders use this to build and fly their
planes with the lowest risk.
On the Internet this week, a builder loudly complained that he'd waited a long time to get a crushplate from us. As evidenced by the above photos, the part
is obviously much more than a simple off the shelf crushplate. This doesn't even touch on the moldmaking, fiberglass samples, or any of the detail design
work. Although we intended to perfect this far sooner, most reasonable builders understand that other issues like optimizing the new crank nitriding
procedures and testing the results served the immediate needs of far more builders than having this unit available six months ago would have.
The post not only simplified the description of the part, but also deleted the fact that he promised a lawsuit over it. All ironic considering
that we never cashed the check he sent for the part, just returning it with a letter which prompted his post. Unlike the heads of most companies in our industry,
I build planes. Because of this I know that building an airplane brings out many moments of frustration, and this makes me understanding of the builders' feelings.
In most other experiences in American consumer life, you can spend your money and expect instant gratification. In homebuilding, this mentality only brings frustration.
Most builders recognize that my work is designed to bring affordable powerplants to rank and file EAA members. In the long run, my work on developing the Corvair has done far
more to get them in the air sooner and more affordably. Events like our free Colleges have to be considered in the big picture with minor issues like delays on
bulkheads. It's for individual builders to decide whether our work serves them.
In reviewing Internet notes, I saw many people ask or make reference to a formula for figuring true prop tip speed. In a discussion with several posts,
no one mentioned that every Conversion Manual we've sold since 2002 has included the formula and a graph showing its use. While
some of the Internet sites have the correct formula, none I've ever seen come with any practical experience or guidance. The experience I share comes from
personally testing an enormous variety of props. Web sites with formulas will never come up with a 72" diameter prop turning 3,300 rpm at 195 mph as an
efficient combination capable of producing maximum thrust. Every source without practical experience will tell you how terrible this would be. Here's
the view from reality: This is the exact combination our friend and neighbor Jason Newburg just used to win the Silver Biplane class at Reno. Quiet enough
for everyday use? No. Good enough to beat out slicker airframes and send Jason home with a big trophy and a fat paycheck? Yes. A triumph of practical
experience over theory.
It was also erroneously reported that our Stainless 601 Exhaust Systems do not fit tricycle geared 601s. The Exhaust System actually
fits all models of 601s with tricycle or taildragger gear. Gary Boothe, a veteran of the California gatherings, offered the correct observation that he'd just
seen one successfully installed on a 601 tri-gear. These exhausts are now installed on about 10 aircraft, and the only one that's not tri-geared is our
601. Some of this erroneous information about our Products are simple mistakes. It's easily countered by asking anyone who's been
to our Colleges, seen our DVDs or read our Web site thoroughly.
Speaking of erroneous info on the Net, many months ago there was a very disturbing Internet report that a Corvair pilot in Brazil had been killed in an
accident. The report had a very factual tone and seemed credible. It included such details that the builder was working with carburetion prior to the accident.
I found the report particularly disturbing because the only builder close to flying in Brazil is a great guy named Tadeau. We sent many e-mails back to the
originator but got nothing back in return. This week, we received an e-mail from Tadeau, who is alive and well and had no such accident. I think the incident
was more of a mistake in facts than malicious rumor, but it was disturbing nonetheless.
Just to remind me that the Net is not the only source of disinformation, today outside my hangar a mechanic from our airport carefully and factually told me
a story about V-8 engined Lancairs, and how they never flew because the gearboxes never worked. He presented this with the authoritative tone of someone who was
really in the know. Anyone hearing him would certainly assume he was correct. Anyone except for me, who built and flew a lot of hours in the very aircraft he
was claiming never worked. I didn't even bother to tell him he was wrong. I'm sure your own airport has at least one version of this guy. In the past 15 years
I have met more than a handful of these guys. It is worth noting that some of them owned planes, but I am yet to meet one of them with an airplane he built.
You can't buy experience or crediblity.
A number of builders on the Net were put off by some comments on an unoffical RV builder's Web site. This led to a few shared experiences about poor behavior among
RV fans. With 4,000+ planes flying and twice that under construction, odds say their camp will have a few antagonistic people in it. But keep in mind that all
the RV people, builders and flyers make up only 10% of the EAA. It seems like more because they have an evniable track record of action. I have to strongly
agree with old school Corvair builder John Bolding's personal observation that considering his accomplishments, Richard van Grunsven is one of the most humble
people to ever set foot in our industry. You can't know him by looking at the least civil act of a member of his fan club who probably never spent 5
minutes in conversation with him. Personally, I get a chuckle out of anyone who thinks of RV people as "elitist." Anyone who feels this way has not yet met
Lancair IV-P owners.
Corvair College 10 is the place to come if you want the actual facts revealed by testing and personal flight experience. You can come and learn in the
presence of like minded aviators who have built or are building machines to successfully pursue their dreams in aviation. My ultimate retort is to run
this event in the most factual, interesting and fun way possible. We'll make it a haven for open minded positive people.
Grace's ultimate retort: Good times
The reason why I love my wife, # 1,526. After a long week of working in the hangar, I return home to find Grace and her father, Bob, engaged in
a beautiful father daughter day. They shot a few hour's worth of trap with pump shotguns in our back yard, then went to the dog track, won the longshot trifecta,
superfecta and several quinelas, and
spent their winnings gorging themselves on seafood at a waterfront restaurant. Don't write in. I'm well aware I don't deserve such a woman.
Notes From California
I've just returned from Cloverdale, Calif., where we held a tech seminar and Open House at Quality
Sport Planes, Zenith's West Coast facility. Michael Heintz hosted the event. He did an outstanding job
of welcoming Corvair builders to his hangar.
The event kicked off on Friday with a small group tech session organized by Michael. This mirrored a
session previously held at his facility for Jabiru builders. The latter part of the weekend was open to
Corvair builders in general, so that everyone had a chance to come and learn, have their parts inspected
and hang out with friends. In the photo above, I'm wearing the Sensenich shirt addressing the tech class.
The airplane we used for the demo is a Quick Build kit that belongs to West Coast builder Woody Harris.
Woody picked me up at San Francisco airport, we loaded his fuselage and engine into a race car trailer,
and proceeded to Cloverdale. This is what his firewall looked like when we arrived at the workshop. In the
background is the Jabiru powered Quick Build kit which was the subject of Michael's prior tech session.
Our event overlapped with Michael's Open House for West Coast Zenith builders on Sunday. While there, we had
a good time with 601 builders using Lycoming, Continental, Rotax and Jabiru powerplants. The mood was
exceedingly friendly, and operational information and notes were exchanged among pilots.
On the Internet, often cantankerous debates take place on engine selection. These are most frequently started
by builders without flying planes. If you're a quiet observer, it's worth noting that this is a figment
of the Net. In person, the mood is pure camaraderie amongst operators of all engine types.
Although we focused on Woody's installation, we had ample time to go over other individual engines. On
the extreme right in the photo above is Gary Boothe, a veteran of Corvair College #5
in Hanford, Calif., who brought his near complete Corvair conversion for inspection. His crank had
an ampersand on it, indicating it was factory nitrided. However, it was ground .010/.010, which negates the
factory nitriding and requires re-nitriding. Testing we've done confirms the long held belief that factory
nitriding on Corvair cranks works in its standard form, but requires re-nitriding if the crank has been
Here's a look at Woody's panel. Economical, but enough instrumentation to cover a huge array of flying
adventures. Woody's decades of experience in the automotive racing world predispose him toward traditional
analog gauges. His tachometer is the same Stewart Warner we use, but with a slightly different face. Woody
chose to use a slightly different switching pattern for his ignition systems and pumps. It made sense to him,
but I would not recommend it to pilots in search of the ultimate simplicity. I noticed one error in his panel we
commonly see: He has a standard magneto key switch. Magnetos work by grounding the p-leads. You can
wire one of these switches to operate 12 volts to the coils. The off and both positions will be reversed.
But here's the hitch: You won't be able to take out the key in the new off position. The solution is to avoid
mag switches and run an automotive key switch if you choose to start the plane with a key. Our 601 does not
have a key.
Woody's plane has the dual stick option and is set up to use a standard aircraft throttle and
mixture in the center of the panel. These controls will operate an MA3 carburetor. Many control and carb
combinations will work on a 601, however, if you're a builder without any prejudices or preferences, the
dual stick, MA3 throttle combo is my optimal recommendation.
John and Jean Kearney of Reno, Nev., made a special trip in with their running 601 engine to share it with
builders. They took time to do this in spite of being in the midst of moving to Fargo, N.D. The effort
was much appreciated by the builders on hand. John and Jean are also veterans of Corvair College #5.
The engine seen in these photos was torn down at that event. It was built up under our
supervision in our Florida hangar. Having the running engine on hand gave everyone the chance to
absorb firsthand operational experience. A test stand like this affords the opportunity for builders to touch
the intake manifold above the idling carb with their fingertips and have direct sensory understanding of
carb icing potential.
Above, I explain the installation of the Front Spinner Bulkhead. This bulkhead is only required when
mating a Warp Drive prop to the Van's 13" spinner. When I returned from California, Grace told me that the
long awaited CNC crushplates were done at the machine shop. Matt at Lahti Aerospace called to report that
he's finished his first composite bulkheads. In a few days, these parts will be on their way to customers
who patiently waited. While I certainly understand the ocassional request for an info update on this part,
it's hard to describe how many many hours go into perfecting the tooling and production of seemingly simple
parts. Several molds were made for the bulkhead, each subtly different, and test parts were constructed. Two
different manufacturers were used, both for the bulkhead and the crush plate. This was not a first
priority job because other parts in development were needed by more builders far earlier. Very expensive
handmade originals were sent to builders with the planes that are flying. Merely adding the criteria that
the parts must be made affordable in line with the Corvair philosophy is the trump card. Today, we've
brought this all together for the benefit of all builders who will use Warp Drive
props. When the backorders are filled, this new product will appear in our
Here, Woody Harris works on his installed engine. It is a standard 2,700cc with Falcon Heads that
Woody built himself using all of our Conversion parts. While our customers build
very good engines in general, most of them have small details which, while not affecting airworthiness,
leave them slightly short of the Engines we build in our shop. This is to be
expected as we're professionals, and our amateurs do an outstanding job for first time builders. With
this understood, I'll say that Woody's engine is the closest customer built example I've seen to matching
our production engines. His engine had ARP case and head studs, and a very high level of finish. It may
have been two different colors, but it's only one level of quality: Excellent.
Woody is a very outgoing and modest builder. When I first met him I asked him what he did for a living,
and he told me, "I work on cars." Something inside told me he didn't change oil on Toyotas at Jiffy Lube.
On the visit to California, we passed through his MSI shop, a high end tune up and road racecar import operation.
It's the first shop I've seen in a while with a chassis dyno built into the floor. Amongst the racecars,
mechanics, slicks and lifts are momentos from decades of all out effort at tracks from coast to coast. '
Almost all the builders on hand were assembling their own engines rather than purchasing a finished one from
our shop. In light of this, I went well beyond installation and covered subjects like the valve adjustment
I'm doing here, and Front Starter installation. I forgot to pack my custom
bent 9/16" wrench that I use for this job. Woody emerged with a Snap On part # XO-1618, which is an off the
shelf wrench capable of doing the same job. In the photo above, Richard Vetterli and Gary Boothe find the process
An early morning shot of the group around the Kearneys' engine. Cloverdale is an exceptionally beautiful
setting for an airport. The atmosphere was far away from the hurried and hectic pace of Oshkosh. West Coast
builders who haven't had a chance to make a visit should
call Michael and make arrangements to do so.
His business is built on outstanding customer service in a friendly atmosphere. This combined with his
family's proven products is a combination worth any Corvair builder's serious consideration.
Corvair College #10
Four Corvair Powered KRs At The Gathering
Building Philosophy: Case In Point, Ignition Systems
Notes From The Hangar
Four Days Till California Meet
Corvair College #10
This is the official announcement for Corvair College #10, Armistice Day weekend, Nov. 11, 2006.
We'll have further updates in the coming weeks, but wanted to give everybody a heads up right now with
six weeks to go. This will be the 10th major College that we've held. As always, it is a free event.
If you have not attended before, you can get a good idea of the flavor by reviewing
Corvair College #9 on our Web site. I'm hoping to draw more than 12 Corvair powered
airplanes to the event. Nine Corvair planes at College #9 was a sight to behold. With this many
planes and pilots on hand, builders have a chance to see their own favorite plane in action, and get
direct firsthand information in person from the best source: Someone with time in type.
Our Colleges are fun, social events. Yes, they're about learning. But, enjoying the company of
like-minded aviators has always been the centerpiece of our events. If this sounds like your style, you're
more than welcome. Bring a friend, or come meet new ones. The event is the cornerstone of the year in the world
of flying Corvairs.
There will be only one significant difference to previous Colleges, and it's important that builders
understand the difference and why we're instituting it. At prior Colleges, we worked on dozens of builders'
engines simultaneously. This worked because it jumpstarted a lot of builders' projects, and finished
many others' to running engines. But the system had three major issues: The 80+ builders last year taxed
our resources in terms of engine building stands, table space and most important, the ability of Kevin and
I to supervise the critical engine assembly of so many builders. (We later disassembled, checked and
reassembled two engines that went together without our direct supervision.)
Second, too many builders get
focused on one small step in their own engine. They'd be much better served watching two engines go together,
asking questions, taking notes and photos, studying the process all the way through. We've had builders
attend a College and spend a weekend putting their bottom end together. While this is progress, they later
find themselves at home missing the firsthand experience of how to install a cylinder head, although it was
done by a dozen other people in the same hangar. An intense overview of the whole process is much better
preparation to replicate at home at an unhurried pace.
The third issue is also important. With the rising
popularity of Corvairs, last year's event attracted a very small number of people who came primarily because
they could get their engine assembled for free. This is obviously contrary to my mission of teaching people
and the spirit of the College, which is all about having fun. While two or three people out of nearly 100
is a tiny fraction, the mission of these people dictated that they were impatient with my crew and did not
respect the good times of others.
Builders coming to have their parts inspected, to observe and learn by participating in two
builds, and have a good time making new friends and perhaps doing a little flying will find the event to be
the great success that all the previous ones have proven themselves. Only people who do not care to learn,
make friends or have a good time will find this new format "a waste of their time."
I encourage builders to bring their parts for inspection. The two builders whose engines we've selected for the
assembly process are Scott Thatcher and Fred Roser. Both of these guys have shown themselves to be complete
gentlemen on numerous occasions. This was the primary reason I selected theirs as the demo engines.
We'll have more updates in the coming weeks, but plan accordingly. For people who want to make accommodation
reservations early, we recommend you call the Best Western hotel, (386) 427-7101, built just around the corner from the airport
since the last Corvair College here. This is a nice hotel at a national level, and you should ask for the
"Corvair College" rate. Some builders
have had the real Edgewater experience in terms of lodging, and the Best Western is nothing like that. We'll
have the full lodging list up shortly for the truly adventurous to help you get ready for
an event you won't want to miss.
Four KRs at The Gathering
This past weekend was the Annual KR Gathering, in Mount Vernon, Ill. Four Corvair/KR pilots flew in their
birds. Certainly a strong showing for Corvair power.
Building Philosophy: Case In Point, Ignition Systems
Several people called this week to say that there was a giant Internet discussion on ignition systems.
Normally, I am too busy to keep up with what's hot for a day or two on a discussion group, but this case
is worth considering. I read back through the archives to get a better picture of what builders
understood and what they missed in these discussions. Even if you're planning on using
our proven ignition system, the discussion is an interesting examination of
builders' philosophies, and the costs and rewards of different approaches. The pattern plays itself out
with every aspect of the engine's installation. It's an opportunity to understand something more about
the philosophies of the people who build airplanes.
Many Internet commenters falsely assume that my crew has only looked at one way of doing things. The photo
above shows various ignition parts, some considered, some tried, some still in the works, sitting on the
shelf next to my distributor machine. Seen in the photo are a low profile crab-style cap with a corrected
firing order from an import; a ball bearing distributor housing from the same engine machined to fit in the
Corvair case; distributor shafts from small block Chevys that have identical diameter and oil pump drive;
HEI ignition system from 4.3 liter V-6, Pertronix points eliminator; Mitsubishi optical trigger; and
miscellaneous other parts. We build and test an awful lot of stuff that does not make it to the discussion
level. Just because we have one way of doing it that has proven to work well does not mean we don't
understand how to do it many other ways, and have considered, tested and perhaps rejected ideas brought up as
new discussions on the Net.
A builder posted that he experienced an on ground failure of an MSD 8210 coil switcher. No one has ever had one fail
in flight. In the Conversion Manual, I outline that it must be insulated from the
airframe. A very important point: You should never, with any type of ignition system, crank the engine
with any of the high tension leads ungrounded. I did not specifically state this in the Manual, but there is
no cause for doing so in normal operation. If I had to guess why the 8210 failed, this would be my primary
hypothesis, and obviously this couldn't happen in the air. This comment from one builder sparked about a hundred
posts on ignition systems.
The four KR/Vairs that flew to The Gathering have about 900 flight hours between them. They all have
our Dual Points Distributor installed. I can think of only two or three flying aircraft that
we've seen in the past few years that didn't use it. Almost every running Corvair has one installed. This is
a pretty strong success story. You'd need a darn good reason to feel that your project should be equipped with
some other ignition system.
Some of the posts raised interesting questions that our research has covered. One builder asked if the
ignition could be locked at 30 degrees. Here's the problem: You need 30 to make full power, yet it's very
difficult for the starter to crank the engine with this kind of advance.
A Front Starter is likely to break an ear off the starter on a kick back, and a rear
starter is likely to shear the key holding the harmonic balancer to the crank. Even
if retarded during cranking, it's possible to get the engine to detonate at 1,500 rpm if the prop is too
large and the MAP is high enough at a low enough rpm. Additionally, most electronic delay boxes that might
satisfactorily perform this task must be used in conjunction with a complex and power hungry CD ignition
Other builders asked about optical switches. The most popular aftermarket stand-alone switch in the world is
a Mallory Unilight. Builders with experience will tell you that optical triggers are rarely used in
applications where absolute reliability is required. They're susceptible to dust inside the cap, and it
should be remembered that a clogged or frozen over breather will lead to oil vapor inside the distributor
body, which will interrupt the operation of the trigger. But the main form of failure is due to voltage spikes.
This is serious enough concern that Mallory now makes a filter specifically to protect the Unilight trigger.
Several people commented that their modern cars seemed to run great with computerized ignitions, and
proposed using some type of modern car system on the Corvair. Besides other issues, "I owned one and it
worked great in my car" needs to be balanced against what experienced field mechanics say about those
components. A while back, I was speaking with Mark Petniuas about GM HEI systems. Owning a shop and being a
full time mechanic who's studied these systems in great detail allowed him to share the thought that if I wanted
to use an HEI system, I should experiment with a four-pin module and a trigger from a distributor with no
vacuum advance, as practical maintenance on these vehicles had shown him that the subtle movement of
the vacuum advance sometimes causes the internal coil wire to fail. Ownership of a vehicle and even light
maintenance on one doesn't give you this kind of detailed perspective on systems. The only mechanic I know
who's regularly on the Internet with this level of background is Clare Snyder of Canada, who I believe
is using points and a snowmobile carb on his running Corvair.
In Contact! magazine many years ago, a builder wrote in to say that he had built an EFI/ignition system for
his Japanese-engined RV-6, and 15 minutes after an alternator failure, the engine quit because of a combination
of the high current draw of the system, and its requirement for steady voltage for the electronics. His
aircraft was severely damaged. He wanted a response from the outspoken advocate of the system he
had just used to reverse engineer his plane back into project status. This advocate had a similar system
on his plane and had written a glowing review. The advocate's printed response was about amp
hour ratings of batteries and power consumption. It was all a simple calculation to him, but clearly the advocate had not
tested his calculations. In reality, the draw
lowers the voltage and the electronics then quit from the lower voltage far faster than the paper calculation
says it will. Real testing is about trying to find how a system might fail in actual use, not toodling around
the pattern a few times and pronouncing something flight proven. Even if it got some time on it, all tests
are not equal. I could re-ring and re-bearing any gooey car motor in my collection, install it in our 601
complete with 40 year old cast pistons, stock rod bolts and a worn crank. If I retarded the timing, lowered
the RPM and made the mixture very rich, I would have a $400 motor which made 60HP at 2300 rpm. I could take off
gently and then fly several laps around America at 90MPH. This is not real testing. The same well traveled motor
installed in Dan Weseman's Cleanex, and operated at full power would have a very short life, perhaps as little
as one good weekend. While you may not plan on flying like Dan, it is importiant to understand valid testing
must match or exceed typical operation.
An international builder proposed building a very elaborate system with dual plugs and six separate coils.
Many systems of this type, even if they have six separate modules, can simultaneously be wiped out by a very
serious voltage spike. Aircraft alternators, static electricity and lightning strikes can provide just such
voltage spikes. I've heard of aircraft strobes getting voltage critical systems. It's something to consider.
By the way, points are comparitively immune to this stuff.
Some of the discussion thought the mechanical advance might be a failure point. I have disassembled
several hundred Corvair distributors and I have never seen one with a broken mechanical advance.
Rusted, from sitting yes, but I have not seen one that is broken from operation. Anyone who spends any time
trying to get around the advance because they feel, based on no experience, that it is unreliable, is wasting
their time, and is almost certianly going to dream up a "solution" which is less relaible than the stock advance.
One of the ironies of these issuse is that many of the people who come up with some system which will
allegedly make the Corvair more reliable are not just mistaken about their igniton ideas, but many of the other
systems which they intend to "improve" on their planes. I have seen a "foolproof" fuel system that had 4 pumps,
6 valves, 12 check valves and enough fittings to fill a small shoebox. The builder proudly upheld this as a
great innovation. Mind you this was on a high wing design which has flown countless times as a gravity feed
plane with no pumps and one valve. If you are new to aircraft building and some of the talk about "elimination
of failure modes" is getting your ear, know this: Risk management in homebuilts comes down to building a good
replica of the simplest system which has been extensively tested in your plane. Then get good training in
your plane and fly it often.
Charlie Johnson, a builder who flys an 1,835 VW powered Dragonfly once asked us how much power the engine
made on the dyno with two cylinders disconnected. The answer is, enough to successfully fly an airplane that
works on an 1,835. This clears the way for a certain type of simple ignition system using three dual tower wasted
spark coils. However, it should be understood that most Corvair powered airplanes will not successfully climb
at gross weight with two sparkplugs grounded out (because it makes less than 66% power dragging two dead cylinders),
which would be a mode of failure in the above system. Unless your Corvair powered plane is super efficient
or a motorglider, our flight experience and dyno say wasted spark systems are off limits.
Builders often cite seeing someone fly a different ignition on another engine, and uphold that this means
it is a good idea on a Corvair. However, this only means that it could work, nothing more. Very few of these guys do what
Dave Stroud did, which is see it on another engine, assemble one on his Corvair and go fly it. It worked for
him, in his application. Systems are proven at the airport, not the keyboard.
Towards the end of the posts, Corvair/KR pioneer Steve Makish made a comment about
flight testing a system with points on one side and a Crane XRI points replacement module opposing the points.
His comment went largely unnoticed, despite being based on actual flight testing. I knew Steve had this cooking
because he had called to borrow a distributor body two weeks earlier. He stopped by my hangar over the weekend
and told me that it had flown fine and that he was going to keep testing. We discussed a purpose built CNC plate
for it. This set up, which obviously works but needs more testing, has my bet that it will prove to be an
innovation which is affordable, buildable and has
no Achilles heal. The potential of this is a good lesson on how stuff happens: A guy who has his plane flying
and debugged works with a little support from us to make a flight tested variation.
Over the years I have had a dozen guys without a running engine tell me that they were going to build a better
ignition. I am yet to see one turn a propeller. Henry Ford said it best, "A man cannot base his reputation on
what he is going to do." I am no smarter than most people, it is just that I have spent an awful lot of years
working with the Corvair, and I have tools like the Dyno, several planes, and the distributor machine at my disposal. I can
see the bigger picture with installation and operational issues which are not apparent to a guy who has not yet
finished his motor. I do not say this stuff to discourage innovation. I just don't want builders who could be
flying to their own Gathering or to our next College sitting at home because someone who has never seen a
Corvair motor turn a prop is talking about how unreliable our ignition system is. One of these people went so
far as to suggest that I support our ignition over others because we make money selling it. I don't think this
was said in a mean spirited way, but it is thoughtless, considering my track record on the crank issue. If I
think something is dangerous, I tell people without any thought of economic repercussions. Every businessman
in experimental aviation says he would react the same way, but the track record suggests there is a big margin
between good intentions and real actions.
Notes From The Hangar
In the above photo, the blue jig is for 601 Motor Mounts. Stacked to the left are
two 601 Mounts that are now in the hands of builders. There was some discussion amongst 601 builders
speculating on the amount of offset to put into a mount. We install very little, about one degree nose down and
one degree offset. Other engine installations in the 601 use several degrees in the opposite direction.
There are reasons for this, but the final proof for each individual installation is in the flying. About 500
hours have been racked up on our mounts flying in 601s and I'm satisfied that we have the optimal amount
for a 601 installation. The 601 is a far more tolerant airframe of variations than others. I would not be
afraid to fly an airplane with 3 degrees of offset, but it would not be my first choice on how to build it.
In the foreground above are two KR-2 Mounts. One of these went to Cary Howard of
Georgia, the other, Glenda McElwee brought to The Gathering and immediately sold. We received an e-mail
asking what our current lead time on a mount is now that we're caught up. I'll call it 30 days, although if
we got more than four or five orders, they'd have to be pushed till after Corvair College #10.
On Friday in the hangar we received the very first of our brand new split-type
nosebowls made by our new composite contractor, Matt Lahti of Michigan. For many years, Matt has run
a high end aerospace composite shop. He'd offered to do the nosebowls a long time ago, but we were
still having them produced here in Florida.
Here's a glance at a manufacturing issue that homebuilders
don't ordinarily get to see. Liberty Aerospace, 80 miles south of us, produces an FAR 23 certified 2-seat aircraft.
This design is so successful, and they're so well financed, they're absorbing every skilled available
aircraft builder in Central Florida. The pay rate is astronomical by Florida standards, and almost all
of the skilled composite guys I know have signed on with them. Tim Hall, who produced numerous nosebowls
for us, is now one of their chief moldmakers. Our goal is to produce affordable parts of high quality.
To compete against Liberty for the skilled labor, our nosebowls would have to double in price. While many
people thought Liberty would be a flash in the pan, they're going strong with solid orders and now have
several hundred people on the payroll. This lead me to take Matt up on his offer.
After some discussion, he and I decided we'd go with a two-piece nosebowl. Although I've never had to
remove the one-piece nosebowl on our own airplane to do maintenance, many people prefer a two-piece
nosebowl. The single operation that will be made significantly easier with the two-piece nosebowl is
dynamic propeller balancing. The cowling seen in this photo belongs to Woody Harris and will be on display
at the California event. Matt is going to make us a few more before I can quote the updated price for this.
His production capability is two to three a week. It is my intention to fill the backorders for single-piece
nosebowls with the new two-piece items. We'll have more news in a week or so.
Above is a good view of the side joggle that Matt built into the nosebowl. Matt's nosebowls are high end
epoxy fiberglas and are bagged into the molds. They'll be shipped with the gray epoxy gelcoat, eliminating the
need for builders to fill small pinholes.
California Meet In Four Days
It is only four days till the California Corvair event at the Zenith facility run by Michael Heintz
in Santa Rosa, Calif. Based on the response we've gotten, I'm expecting a very large turnout. We heard
from John and Jean Kearney of Nevada who'll be bringing their running 601 engine on a stand. Although I've
never been there, numerous friends said it is an exceptionally nice airport, and the facility is
large enough to accommodate any size group. I encourage any West Coast Corvair builder to come, learn and meet other
builders with the same outlook and goals as yourself. Again, Saturday afternoon and all day Sunday are
free events and all Corvair builders, not just those working on Zeniths, are encouraged to attend and
bring a friend. We'll see you there.
Now At The Hangar
June 2011 At The Hangar
May 2011 At The Hangar
April 2011 At The Hangar
March 2011 At The Hangar
January 2011 At The Hangar
December 2010 At The Hangar
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December 2009 At The Hangar
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Christmas 2007 At The Hangar
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December 2006 At The Hangar Part 1
December 2006 At The Hangar Part 2
December 2006 At The Hangar Part 3
December 2006 At The Hangar Part 4
November 2006 At The Hangar
September 2006 At The Hangar
August 2006 At The Hangar
July 2006 At The Hangar
June 2006 At The Hangar
May 2006 At The Hangar
At The Hangar In April 2006
At The Hangar In March 2006
At The Hangar In February 2006
At The Hangar In January 2006
At The Hangar In December 2005
At The Hangar In November 2005
At The Hangar In October 2005
At The Hangar In September 2005
At The Hangar In July 2005
OSH, Illinois and SAA June 13, 2005
At The Hangar June 13, 2005 Part II
At The Hangar In May 2005
At The Hangar In April 2005