William Wynne

"The Corvair Authority"
5000-18 HWY 17 #247
Orange Park, FL 32003

Action Update Oct. 21, 2007
Rouse 601 Airborne
701 Progress
Tech Notes
Sunday Papers Volume II - Oil Systems

The sharp looking 601 in the above photo is the work of Murray Rouse of Iowa. It's the 15th Corvair powered 601 to fly.

Murray's 601 XL is a taildragger like our own. Although the plane is fully painted, it has an empty weight of 788 pounds. It has one of our production engines in it that Murray picked up last year when he attended Corvair College #10. The plane has virtually all of the firewall forward components we manufacture for the 601, including the brand new Gold Oil System components. The prop is a Sensenich 64x43, the same one we use on our own plane. Murray said the airplane flew well and had only one minor airframe adjustment to be made.

Murray is truly an old school homebuilder. He spent a lot of time in Southern California and built and flew a KR while Ken Rand was still alive. He went on to be one of the earliest RV builders. He had a lot of experience with RVs before tackling his 701 project a few years ago. Murray's 701 (which is Rotax powered) was recently featured in a series of full page Zenith Aircraft Company magazine advertisements. ZenVair fans should feel free to e-mail Sebastien at seb.heintz@zenithair.com and campaign for the same exposure for Murray's Corvair powered 601.

It's particularly satisfying to me when a builder of such experience chooses the Corvair as his powerplant. Congratulations to Murray Rouse, the newest Corvair pilot.

701 Progress

A number of people have written to ask about progress on the Corvair powered 701. Above is a photo I shot in Edgewater last week. The airplane is more finished than the photo depicts. The leading edge slats and flight controls, not seen in the photo, are complete and have been mounted. The glass is out of the plane to facilitate the detail work. One builder wrote to ask if it would take a long time to develop installation components after the combination is tested. The engine uses a lot of parts from our existing catalog. The Nosebowl is the same one we use on 601s. The sheet metal to mate it to the 701's airframe will be different, something reminiscent of a Thorp T-18. All the engine parts, including the Baffling, oil cooler and oil system, Starter, Gold Hub and alternator are our standard parts. The exhaust system is made from 601 Exhaust pieces in a slightly different orientation. The only truly unique pieces are the motor mount and lower intake manifold. Even the prop and spinner bulkhead arrangement is the same as the 601.

While it's convenient that many of these pieces can do double duty, the real reason we're inclined to use them is because of course they work and are fully tested. Qualities that have a real appeal when it comes to test flying new combinations. Thus, after flight testing, I believe that builders who wish to replicate the installation will be able to do so quickly. We'll keep you posted.

Tech Notes - Good Idea, Bad Combination

I recently read a thread on the Internet where a new builder proposed using a combination of Bernie Pietenpol's ultra simple Corvair conversion ideas with some of my current work. While his thoughts struck most of the people on the discussion group as harmless or not worthy of comment, my experience immediately spotted a serious flaw in his logic.

This builder was proposing building a hand-prop Pietenpol style conversion using our overhaul techniques. All of Bernie's engines were hand propped, but they were well worn engines from cars. A freshly overhauled Corvair engine is very difficult to hand prop. This is a major practical difference between engines of yesterday and today. Here's a more critical consideration: He proposed using Bernie's hub. True enough, Bernie's hub has flown thousands upon thousands of hours. Add to this that 66" and 68" Warp Drive props have flown thousands upon thousands of hours on modern Corvair conversions. Inserting a third piece of the puzzle, like a snap ring, an idea proposed by a friend of ours as an alternative to a Safety Shaft, makes a very dangerous combination. While our Hub flew on several airplanes with a snap ring, it is absolutely critical that people understand that Bernie's hub counts on the Safety Shaft to retain the hub. We use long long Hybrid Studs to clamp down the Hub. Bernie's hub uses the stock short bolts in very deep wells. Without a Safety Shaft, and with a prop like a Warp Drive, a Bernie hub would likely fail in minutes. This is why I emphasize that builders must use proven combinations, not collections of individually proven parts or experience extrapolated from other sources.

We wrote the builder and explained a lot of this to him. His proposed combination and some comments he made on the Net suggested that he was yet to understand that my experience with the engine and installation would be a large factor in the success of his own plane. If you're considering a combination of ideas beyond what's been flight tested, take the time to run it past me. I'm glad to share what I know with anybody serious about building.

Sunday Papers Volume II - Oil Systems

Here's the continuation of our look at specific aspects of the Corvair flight engine. I have done more testing of oil systems than most people can imagine. A good read of our Web site will show you tests that we ran 10 years ago. I've been continuously gathering data by specific tests, building engines and flying them. I have the large scale perspective that very few others can appreciate. While a handful of builders have experience on a specific aircraft that works for them, my knowledge is based on working on dozens of Corvair powered planes. Four or five years ago, I wrote a large piece called "The Mother Of All Oil Posts" for the Net. The following article builds on the base of earlier tests and presents proven systems, flight tested ideas and a selection of pitfalls to avoid.

The Corvair has an outstanding oil system. Builders are disassembling hundreds of core motors a year. These come from cars that have been sitting for many years. Most of these cars never received an oil change the last two or three years of their lives. They were continuously run low on oil and beaten like dogs. Yet just about every builder is rewarded with a crank that can be polished, or have a simple .010/.010 regrind. This is all the evidence you need to appreciate the quality of the GM design. Just like the Doctor's Oath, your first vow is to do no harm. Many modifications that inexperienced builders propose are a serious reduction on the Corvair's reliable oil system. Until I understood the operation of the system, I too took detours. My Pietenpol was the first Corvair to fly with a rear starter. It used a 3-hose oil system, an arrangement I now consider a mistake. Read the information here carefully, and you'll avoid repeating missteps people have already paid for.

All Corvair engines need an oil filter, oil cooler, filter bypass and cooler bypass. The above photo shows two pencils pointing at the Corvair's stock bypasses. The one in the rear case is the cooler bypass, and the one in the top cover is the filter bypass. They're both set to open at 7 psi (they're the same part). You can read all about my testing of oil accessory cases and the specific rig we built to do this on our Web site. Systems without bypasses, particularly cooler bypasses, will starve the engine for oil. Five years ago, we tested filters and coolers by packing them in ice to simulate a start at 32F. The cooler bypassed for more than 10 minutes, whereas a filter packed in ice only developed a 2 psi differential. Coolers without bypasses can cause massive restrictions in oil flow. If your pressure sending unit occurs before the cooler, you'll have no idea that the pressure to the bearings is dropping on every start.

Six Oil Systems That Work
The following six systems are examples of good systems and planes to which they apply. The pros and cons of the systems are weighed in.

  • 1. Completely Stock Oil System
    If you're going to run a stock oil system, you should only use 12-plate or folded fin oil coolers. These must be spotlessly clean inside and out. Many simple planes over the years flew with hand prop engines and completely stock oil systems. The oil filter that's most accessible is a NAPA 1038. Several Corvair parts houses sell spin on adapters for other filters. These leak so frequently that I'd never consider using one on a car, far less an airplane. One major issue with stock systems is that there's no good place to take the temperature of the oil. Welding a boss on the pan is OK, but it reads deceptively cold at first, and at other times can read the temp of the metal of the pan, not the oil.

  • 2. Stock With A Pietenpol Oil Jacket On The Intake
    If you're a Pietenpol builder with a set of Bernie's conversion plans, you've seen that he jacketed a section of the intake manifold with hot oil to improve the fuel distribution and cool the oil slightly. Pietenpols like The Last Original have this system. While it obviously works, it has some big limitations. First, I know of several engines wasted by ingesting slag left over by the inside of this weld. Second, the oil lines that feed this tend to be restrictive. Third, this system doesn't really provide significant protection against carburetor icing.

  • 3. Remote Filter With Oil Cooler In Stock Location
    This is a popular approach that we've used on many installations, including both the Cleanexes, Dave's Wagabond, and some 601 XL installations. Our Oil Top Cover is the beginning point of this installation, above. (The cooler in this photo actually makes it a #4 system, but it's a good photo of the Oil Top Cover.) Two AN-6 lines run from this cover to a firewall mounted oil filter housing. The housing we use is a Perma-Cool Part No. 1791 with a K&N 1002 filter. The instrumentation on this sytstem is very easy because the housing has 1/2" NPT ports, which provide a great spot for oil pressure and temp readings. If you're building a Cleanex, it should be noted that this system fits around the stock fuel filler neck, while systems #5 and #6 do not.

  • 4. Remote Filter, Remote Cooler, 4-Hose System
    The flight testing of this system was accomplished on our own 601, above. Most 601s use this system, and a lot of people have seen it on Rick Lindstrom's Kit Planes 601, N42KP. The system is essentially the same as #3, except a Perma-Cool Part No. 181 sandwich adapter is added between the oil filter housing and the filter. This adapter has two 3/8" NPT ports which lead to the inlet and outlet of the cooler. A good indication of the effectiveness of this system is Rick's airplane flying over the Rockies to California. The plane was at or slightly above gross weight, and experiencing abnormally high OATs in excess of 100F at 6,000'. To get to its absolute ceiling, the plane climbed at 80 mph and WOT for 60 minutes straight. The oil temp only hit 240 F, before the cooler. Very few other engines have reserve cooling potential and systems that would shrug off punishment like this.

  • 5. Gold Oil Filter Housing, Stock Cooler
    The Gold Oil Filter Housing was the result of a lot of thought, testing and design work. It takes the ultra efficient K&N 1008 oil filter. The housing contains two 1/8" NPT pressure ports and a 1/2" temperature port. The temp port is designed to measure the highest oil temp in the engine. This system will have no external hoses. The 1008 filter has its own bypass inside, and the stock Corvair cooler bypass is left in the case. This is the system that Gary Coppen has chosen to install on the Skycoupe. One of his airframe overhaul goals is to reduce the weight by 60 pounds. This setup will play a small but important role in weight reduction. We sell the Gold Oil Filter Housing for $229. While initially this may seem expensive compared with the #3 system, consider that it saves you from making two braided lines with four full flow hose ends and two AN fittings. The material to build these lines properly costs about $120, and the 1791 housing is about $25. So it's less expensive than its initial impression. Looking at the big picture of the complete installation often changes your perspective.

    If you're using this system, you must be absolutely sure you have a clean 12-plate or folded fin cooler. Any chip of junk that's dislodged in the cooler will go straight to the bearings. Keep in mind that the filter is upstream of the cooler.

  • 6. Gold Oil Filter Housing, Remote Cooler
    The above photo shows the #6 system being set up for lines. In between the 1008 filter and the Gold Housing is a Gold Bypass. This custom Bypass is CNC machined to match our Housing. When using this system, you must remove the stock oil cooler bypass from the rear case and fabricate a 1/4" aluminum blockoff plate to cover the two oil cooler outlet holes on the case. This significantly streamlines the oil system internally in the engine. This system is similar to a #4 system, but is more compact and only requires two external hoses. The cooler we use is a Niagara 2002, available from us for $239. The above photo shows my preferred position for a cooler on a Corvair. Our Baffle Kits are set up to allow the installation of the Niagara cooler in this position. This is how our production engines are delivered.

    We flight tested a whole collection of coolers in various locations, and the Niagara mounted on the engine was the clear winner. The cooler shown on our 601 above is actually a 2003. This is overkill for a Corvair. On a 70F day, if the 2003 is not partially blocked, it will take an hour for the oil temp to reach 160F. The 2002 is the one we sell and is a much better all season cooler for the Corvair.

    Operational Limits
    I do not like to operate the engine under full power when the oil temp is below 150F. The minimum temp I like to see in normal cruise is 180F. Oil must reach this temp at cruise altitude for the water in it to be boiled off. All aircraft engines end up with some water in the crankcase from condensation and byproducts of combustion. Regular operation at temperature drives this out.

    We've made sustained flights with high quality oil at 260F. I have it on good authority that Shell Rotella T oil can withstand continuous operation above 300F. Amsoil can go far higher than this. A very important note: If you have a Corvair engine with gradually decreasing pressure but high temp, immediately suspect a bad bearing in the engine. Corvairs are very good about giving long warning of disintegrating bearings. The most common reason for disintegrating bearings are mistakes made in plumbing the oil system.

    Oil Recommendations
    The only oil we use in engines today is Shell Rotella T 15W40. It's readily available and has the highest temp tolerance of any mineral based oil I know. We use this for break in and normal operation. As an option for extreme duty or turbo motors, Amsoil synthetic 10W30 oil is my choice. Both of these are 100% compatible with 100ll fuel.

    It's important to note where the oil temp is measured. Pan measurements vary greatly on engines. The only reliable numbers are in the oil stream. I like to measure the oil temp before the cooler. A stock Corvair cooler will knock 20F off the temp. If you have a system that measures post cooler, you need to take this into consideration when comparing numbers. The lowest pressure I like to see in a hot idling Corvair engine is 15 PSI. The highest pressure I set the engine for is 42 PSI cool, which will decrease down to 38 when the engine reaches its full temp. Any Corvair engine can be set up to have adequate pressure with a stock oil pump. A high volume pump will merely mask a poor fit on the bearings or excessive clearance somewhere in the engine.

    Years ago, when we were first making Deep Sump Aluminum Pans, something I constantly read on the Net was that the Pan was not correctly baffled and would somehow suck air. To prove this wrong, we actually blocked up the Skycoupe and chained it down at a 22 degree nose up angle. This is a lot more than it sounds. We ran the engine at full power for several minutes. The main gear were on knee high stacks of concrete blocks while the tail actually touched the ground. Often, people would ask about descending. This is where I could clearly tell the person asking had no practical flight experience. An airplane descending power off tends to maintain a near level attitude because the wing actually experiences a significant angle of attack because of the descent. If you're new to flying, the book Stick and Rudder, the best book ever written on the technique of flying, covers this in detail. In short, we have dozens of Aluminum Pans flying on airplanes, and no one's ever mentioned a loss of oil pressure in any maneuver.

    Myth #2
    Horizontal oil filters like the 1008 leak oil when removed - this is bull. At a recent airshow, I was displaying the Gold Oil Filter Housing and one of the people in attendance stated for everyone else to hear that he'd use the system, except clearly the oil was going to leak all over the engine when the filter was removed. I had to bite my tongue because when you do this for a living, you recognize some people who are never going to do anything want to pin their inactivity on someone else. I pointed out that the 1002 and 1008 filters have internal rubber flappers that prevent oil from leaking out when they're unscrewed. The fellow said he was sure one or two drops would leak out and that was too much for him to tolerate. I suggested he look into gliders because they're the only type of aircraft with no oil involved in the maintenance.

    Mistakes To Avoid In Your Oil System
    Never use thick oil in a Corvair. I recently inspected a Corvair powered plane with a damaged engine. Right on the outside of the cowling proudly displayed were Castrol Aviation Oil stickers for 50 weight oil. The numerous times we've encountered people using thick oil, it's always because some local "expert" at their airport told them to. It never ceases to amaze me the type and variety of incorrect advice people will freely dispense.

    Never use hard 90 degree fittings with square intersections. Personally, I don't even like hard 45 degree fittings in oil systems. The above photo shows a collection of full flow Earl's hose ends. They are 180, 150, 120, 90 and 45 degree. These are the only style of hose ends you should use in your oil system. Note how the bodies of these hose ends are shaped like tubes. They have virtually no drag compared to a 90 degree intersection fitting. Braided hoses are very easy to make with the $40 cutter shown in the photo. It's available from SummitRacing.com

    Never use a 3-hose oil system. A 3-hose oil system runs one line from the engine to the filter; then one from the filter to the cooler; and a third from the cooler back to the engine. Our Piet had one of these systems, where the oil entered and exited the engine from the stock oil cooler location. The downfall of this system is that the drag from the cooler forces the system to bypass the cooler and the filter for the first 10 minutes of operation every time you start it. During this bypass period, oil pressure is actually 7 or 8 psi lower at the bearings than is indicated by the gauge. The oil filter stays deceptively clean. Far worse are 3-hose oil systems where the oil enters and exits the engine from the oil top cover location. These systems have no cooler bypass, and will have greatly reduced oil flow to the bearings on every start. The cooler becomes the restriction in the system, but there is no method for oil to get around it and bypass it. Without a bypass, the oil heats up very slowly, so the negative effect of this system takes place for a longer period on every start.

    I've seen systems that combine hard 90 ends, the 3-hose setup and thick oil all in the same installation. This is stacking the deck completely against you.

    Do not use -8 hoses on a Corvair. -6 lines with proper end fittings have shown themselves to be more than adequate. -8 hoses are heavier, require a bigger turn radius, and have much larger hose ends that lead people to hard 90 fittings. Additionally, -8 hoses are much more prone to kinking because they won't turn on a tight radius and are just large enough in diameter to kink when bent too tight.

    Never try to duct air over the pan to cool the oil. Cooling systems on engines work simply because there's higher pressure on top of the engine than below it. Even on a good cooling system, the difference is slight. It's measured in inches of water. It's way less than 1/2 psi. When people try to duct air to the pan, they're opening up a high pressure duct to the underside of the cooling system. This makes air in the cowling stagnant. If you need to cool the oil, use an oil cooler, not an air duct to the pan. Every device allegedly used to cool oil that's attached to the pan, valve covers or top cover is always inferior on a pound per pound basis to a proper oil cooler.

    Action Update Oct. 14, 2007
    Corvair College #11
    Roser's Running Engine
    Thomasville Fly In
    Oil Pan Production
    Sunday Papers Volume I - Ignition Systems

    Here's the latest update from our workshop. I want to keep everybody reminded that Corvair College #11 is less than a month away. If you've never attended a College, Zenith's Quality Sportplanes in Cloverdale, Calif., is a wonderful facility, and this College promises to be one of the all time greats. West Coast events we've held have always been well attended, and California builders have a work hard, play hard ethic that makes them prolific aircraft builders. Read about the previous Colleges on our Web site at the pages on Corvair College #5 in California, Corvair College #6, Corvair College #7, Corvair College #9, and Corvair College #10. And check out Zenith's Quality Sportplanes information at http://www.qualitysportplanes.com/qsp-2006_077.htm on this upcoming event.

    Above, Fred Roser's engine doing its break in run in front of our residential hangar. Fred is known to many other builders because he put on a very impressive PowerPoint presentation at Corvair College #10. Two years ago when we were operating out of the Edgewater hangar, we met Fred when he was starting on his 601 project. He's a very positive person and he quickly fell into a group of builders who made frequent visits to our hangar to work on their own engines. These informal workshops were fun and provided us with good feedback and an opportunity to assist builders in making a lot of progress. Other members of this group are Scott Thatcher, whose 601 is nearing completion, and Charles Leonard, whose 601 is about done with its 40 hour flight test period.

    Fred's engine is the last one of the group to hit the dynomometer. I worked on it during off hours to finish it and close this chapter of my work with the Corvair movement. Although projects like Fred's group took a large amount of time, they were necessary to bring the Corvair movement to the level that it is today. However, with our new concentration on production, this is an example of things we used to do. Now our service to the movement is primarily making parts to keep people progressing.

    The above photo does not do justice to the beautiful craftsmanship of Jim and Rhonda Weseman on the now available 601 Cowling Kits. The kit contains all the sheetmetal components between the Fiberglas nosebowl and the 601's firewall. The kit has a roll formed top center section which is completely done with the top hinges installed. The complex bottom panel with the air scoop, carb heat/filter box, is completely formed, riveted and ready to install with its hinges. The only kit aspect of this product is the material for the four side panels which are left long to accommodate builder variations in individual airplanes. Details on the kit are very nice, including rubber seals on the carb heat arm, cable clamps for its operation, and a felt seal on the intake door. The first three kits were purchased by Jay Bannister, Scott Thatcher and Alan Uhr. We have two more currently in stock. Although they might seem expensive at $489 including S&H in the U.S., they have more than $150 in material in them and will save even a productive builder a solid week's worth of effort. We'll have more photos and a Products Page link shortly.

    In the above photo is Dan Weseman and two of his boys next to the nose of Dan's Wicked Cleanex in Thomasville, Ga., Saturday. Thomasville is a three-decade old event that traditionally draws 300-500 beautiful aircraft running from homebuilts to classics to antiques. It's a relatively commercial free event where camping costs nothing, your complete lunch is $4 and admission is free. It's well known as a great social event with a lot of campground activity after hours. Because it is not an EAA Regional Fly In, it's not as well known nationally as events like Copperstate, although it generally has more airplanes on hand.

    Corvair builders who flew in included Dan and Family. Gary Coppen and I went up for the morning and saw a lot of old friends there.

    This photo of Dan Weseman's Wicked Cleanex was taken on its way home to Florida. Dan said the event was one of the best times he's ever had at a fly in, and he can't wait till next year at Thomasville. At the recent KR Gathering, a builder just getting started outlined to me a complex series of modifications he wanted to perform to the Corvair engine in order to "build a fast engine." This gentleman and a minority of builders mistakenly believe that the simplest of Corvair installations, the type I recommend, are only for Pietenpols and 601s. I pointed out that Dan and Chris Smith's Cleanexes are outstanding high speed performers equipped with Front Starters and alternators. The Cleanex even sports the ultra simple stock 12-plate Corvair oil cooler in its stock location. In an upcoming update, I'll cover oil systems and elaborate on the advantages of simple configurations. In general, builders should know that the engines we advocate serve all aspects of Corvair performance.

    If you're one of the builders who's patiently waited for one of our Ultra Light Weight Deep Sump Aluminum Oil Pans, good news: The above photo shows an 8" deep stack of Oil Pan rails fresh from the CNC machine shop. These rails are the basic building block of the Pan. When I work my way through this stack, we'll have Pans to spare on the shelf. It will also bring the number of Pans in the field to about 300. Our Pan is one of those parts that's not discussed a lot, but appears on virtually every Corvair powered airplane that takes to the air these days. In recent years, just about every Corvair powered airplane at a major fly in or Corvair College #10 is equipped with one. KRVair pilot Mark Langford has more than 500 hours on his Pan.

    Above is a photo of an uninvited guest who stopped by our home hangar for a visit. People who watch the Weather Channel know that Northern Florida received more rain in the past two weeks than it has in the past 18 months. High water means snakes on the move, like this 3-foot water mocassin. These snakes are not agressive, but they are very curious, completely fearless of humans and can be deadly poisonous. I politely asked the snake to leave, but it came down to a job for the .410. If you don't like bugs, Florida isn't for you, and if you don't like snakes, rural Florida really isn't for you.

    Speaking of hangar visits, we received an e-mail from a man "thinking of building a 601" who wanted to stop by the hangar for a "one hour ride." We politely explained that this is not part of what we do now. His return e-mail was less than friendly, and he asked how our program served his needs. While we're very grateful to the coverage in Kit Planes magazine of Rick Lindstrom's 601 project, and it has brought many new real Corvair builders into the movement, it had the undesirable side effect of also bringing us a lot of people merely looking for a ride in an airplane and some entertainment. To answer the e-mailer, we're serving hardcore homebuilders by dedicating our time to building the parts they need to keep their projects progressing. The no visitors policy, combined with my travel to events like Corvair College #11, serve the serious builders, those willing to learn, build and fly.

    Above, if you look closely in the morning sky, you can see the trail left by an Atlas rocket going into orbit. I shot this from our front yard, 130 miles from Kennedy Space Center. As we approach the end of the Shuttle program, I urge any American who has never seen a launch in person to make arrangements to see one. A night launch is visible up to 250 miles away, so imagine how good it is from 10 miles out.

    Sunday Papers Volume I - Ignition Systems

    This is the first in a series of technical papers giving an in depth look at a particular aspect of a Corvair flight engine. A lot of the information on this part of our Web site is news and events oriented. The Sunday Papers are intended to be educational and timeless, something you'd print and keep with your Conversion Manual. If you're one of the people new to the Corvair movement considering attending an event like Corvair College #11, the Papers will serve as a perspective on the scope and depth of my knowledge on Corvairs, which is free to anyone, and the place to come to learn.

    When I was 18 years old and getting started in drag racing in New Jersey, I was working at a drag racing house called Speed World in Union. Our home track was Englishtown, site of the NHRA Summer Nationals. Even the sportsman racing was fiercely competitive. We were fortunate enough to have one of the East Coast champions, Bill Houska, as one of the shop's sponsored racers. In drag racing's single eliminations, defeating your competitor is referred to as "trailering" him. Frequently, in 8 rounds of eliminations, Bill would trailer everyone he came up against. Initially it seemed like magic or voodoo. Only in time did I learn that it was meticulous preparation, checklists and concentration that were the key elements of his success. As a starting point to emulate his success, I copied all his style and techniques, down to wearing the same kind of sneakers. In our youth, he seemed as old, wise and powerful as Obi-Wan Kenobi. He was about 30 years old.

    As you're looking at ignition systems for your own Corvair powered airplane, take the lesson to heart and start by emulating what works. Virtually every flying Corvair powered airplane built in the past 10 years has one of my ignitions on it. The two or three other airplanes that flew without it are yet to log 100 hours between them. No aircraft has ever had any type of a forced or precautionary landing made on our ignition system. It works. Period.

    Above is a wiring diagram that shows the basic layout of my ignition system. This page is taken from our 601 Installation Manual, so it includes some of the wiring associated with fuel pumps. The key elements of the design are redundancy, low power consumption and low voltage tolerance. It's also immune to voltage spikes and high temperatures. No other ignition system that builders have proposed or theorized has these qualities, far less thousands of hours in the air to prove it. I've tried many different versions of the ignition system. Beyond flight testing, having the distributor machine and dynomometer are force multipliers that allow me to examine a bigger picture than is available to anyone who has a favorite theory about ignitions.

    With our system, notice that you can fail one of the coils or one set of points and still have 100% power available through the backup system. Once every few months, a builder will propose a system that has three pickups and a wasted spark system using three coils and two plug leads from each coil. I know these systems well, and they're not safe to use in Corvair engines because with three coils and three pickups, you're statistically more likely to have a failure and when you do, you'll be immediately down to 66% power. However, the dyno shows that dragging two dead cylinders means you're really down to 50% power and most Corvair powered airplanes will not climb on half power.

    Our August Update contains a photo of Mark at Falcon's EFI engine. Note that it actually has six LS1 coils which have built in modules. This is acceptable because a single coil failure will bring you down to 83% theoretical power; about 75% power on the dyno dragging one dead cylinder. This illustrates the point of why it's acceptable to have single plug ignition on a six cylinder engine. The performance loss of one cylinder on a six is not catastrophic like losing one cylinder on a four cylinder engine. Corvair powered airplanes have taken off and flown on five cylinders on three occasions that I know of without incident. This was due to a missing plug, blown head gasket and missing rocker stud, respectively.

    The shot of the workbench above shows 85 Distributor bodies neatly stacked. Over the years, I've reworked several hundred Distributors. I've had the opportunity to examine many of them after they've put in a year or two of flight service. We've continuously had running Corvair vehicles to test all types of ignitions in the ground environment. Many of the theories I was taught and believed 15 years ago proved inaccurate or inapplicable to our situation.

    One of the most important aspects of the ignition system is that it's low voltage tolerant and a low power consumer. There's a lot of theoretically great electronic systems that work fantastically as long as there's more than 11.5 volts available and a steady flow of 10 amps to power it. In the world of flying, where you could have an alternator or voltage regulator failure, and be reduced to the amount of electrical power stored in your battery, these electronic systems are not acceptable. A Corvair engine running one of my ignition systems will run for hours on the battery that started it. The points system will work all the way down to the 9 volt range. Electronic ignitions with computers on other alternative engines have demonstrated as little as 20 minutes flight time with very serious consequences after a charging system failure.

    My new Electronic/Points system utlizing the Crane module is a very low power consumer and additionally has the unheard of quality of producing stable sparks well below 9 volts. No other electronic ignition that we tested demonstrated this. Corvair cars frequently use a system made by Pertronix. While not a giant power consumer, the Pertronix system is very voltage dependent. I searched for a long time to find an electronic system that could complement the points. I had looked at the Crane system, but it was our friend Steve Makish, an electronics expert, who first tested his own version of it. Based on his review of the Crane unit, I evolved our own Dual Points Distributor to Electronic/Points. This system is now flying on the aircraft of Mark Langford, Mark Jones, Rick Lindstrom, Dan Weseman and others. It's my intention for this to be our new standard ignition system. As logic would dictate, we have tried to supply the people with flying airplanes first, before making it a regular part of our Catalog.

    I continuously buy piles of core distributors and disassemble them so we only use parts that are in excellent condition. The distributors above were provided by Bob Bentz, an excellent source of core motors for builders who want to pick them up near Lakeland, Florida. Contact him at (813) 716-1633.

    In the above photo, the Crane unit replaces one set of points. This uses the same coils and systems as our Dual Points Distributor with the exception of eliminating the condenser on the electronic ignition's coil.

    The above photo shows the firewall mounted electrical box from Gary Coppen's Skycoupe. We put this together seven years ago to house all the electrical components and flow cool air over them. The only difference in today's method is the use of Bosch Blue Coils, readily avaiable from Great Plains Aircraft. The Accel coils shown above must have external ballast resistors, which are internal on the Bosch Blue Coils. The top shelf houses the MSD 8210 coil switch. There's some discussion about the use of the Mallory equivalent of this part. The system will work with either; it does not care.

    Above is a sectioned Corvair distributor body showing the location of the dual bushings. Corvair factory distributors only had the top bushing. For many decades, it's been a popular high performance modification to install the second bushing in the bottom of the Corvair's housing. The primary requirement for this is to support the distributor shaft under a load. The ignition system is not the load on the distributor. The work it does driving the oil pump requires at least 25 times the effort from the distributor shaft.

    I occasionally read Internet discussions where an armchair theorist describes eliminating the Corvair's distributor. This illustrates how little some people inspect the engine before speaking. Even with an ignition system that has no distributor cap, such as the EFI system, you still must have a distributor assembly to drive the oil pump. I have long told people to use standard Corvair oil pumps and thin multigrade oil, and never to use oil coolers without bypasses. These oil system issues will affect your ignition system by overstressing the distributor shaft. Conversely, my thoughts on the distributor shaft are now leaning toward a single bearing design. Many companies made dual bushing housings. Clearly the absolute best ones were made by Dale Manufacturing. I've heard the term "Dale Housing" used to describe any dual bushing housing of any quality level. Dale no longer regularly makes these housings because no one is willing to pay what it takes to do them correctly.

    We've long modified the housings ourselves. It takes a long time to do this correctly. There are quick and dirty ways of doing it, but unless the bushings are perfectly aligned, you're better off having only one. Even slightly misaligned bushings will show as housings that run hot in the distributor machine. Additionally, any variation in the hardness of the bushings will produce rapid wear on one of them. Worn bushings show up as dwell variations in points systems. One of the advantages of our E/P Distributor is that the Crane unit is immune to timing changes caused by bushing wear. While the end goal is to come up with a bushing system that will not wear, it is still currently an advantage.

    I've long been in pursuit of an economical replacement distributor body which can incorporate a bearing instead of a bushing. Above, the sectioned stock housing sits next to an idea I'm pursuing. The small end of the housing on the right is a machined billet. It's inexpensive because it's a pure body of rotation and it comes out of a piece of 2" stock. The large end is the stock Corvair end severed on a lathe. The two pieces grafted together are much more affordable than a whole CNC body, which would increase the cost of the distributor several hundred dollars. The two bearings in the photo are a straight roller and a double angular contact ball bearing. Both of these require sleeving the shaft size up. I have one other design that uses a single row ball bearing in a remachined stock housing. This is done and currently in testing, but the stock housing restricts it to being a fairly small ball bearing.

    Having a perfect and affordable bearing/bushing system that is mass producable is the long term goal. For now, orders are filled with dual bushing housings that are individually tested on the distributor machine to ensure they have proper alignment.

    The above photo shows a Dual Point Distributor in the machine. I recently disassembled the distributor machine and overhauled it. It was made in 1950 and has a single vacuum tube inside that I handled very carefully. The items piggybacked on the top row allow the simultaneous operation of the electronic side of the Distributor while superimposing the EI picture on the scope.

    When running a Distributor on the machine, I can vary the rpm it's turning and observe its advance directly. When your Corvair engine is idling, the advance weights in the Distributor are held shut by springs. The advance at this point is referred to as the static timing. I set the Distributors so they have no advance below 900 rpm. As the engine comes off idle, the mechanical advance inside the Distributor's body makes the spark occur earlier. This is the mechanical advance at work. All the mechanical advance needs to be in by 2,400 rpm or so. This way, you can tie the tail of your airplane down, run it to full power and check what the total advance is at the propeller's full static rpm. Total advance for engines running on 93 octane fuel should not exceed 32 degrees. For engines on 100 low lead, 34 is the limit. Beyond these numbers, the engine could be aggravated to detonate.

    Each of our Distributors is marked on the underside with its mechanical advance and the beginning and ending rpm of its curve. Thus, if you have an engine you're going to run on 93 octane fuel, and your Distributor says "18-1,000-2,400," use a timing light to set the static timing to 14 degrees below 1,000 rpm. With the plane tied down, raise the rpm above 2,400 and verify that the total advance does not exceed 32 degrees. A dire warning: Never touch the ignition wires while the plane is running and turning a propeller. There is a remote possibility you'd get a high voltage shock and inadvertently flinch into the propeller. It's a very remote possibility, but a builder in Australia did it and was lucky to keep his fingers.

    The only distributor caps we use are made by Echlin. The tan cap is the heavy duty unit that's intermittently available from NAPA. Both have copper contacts inside. They were made in Mexico for the past five years but have recently been shipped to us with "Made in the U.S.A." stickers and slightly different mold marks. Although the 1830 part is considered heavier duty than the 183, it is Bakelite, not thermoplastic, and therefore more brittle. A VariEZ builder recently returned to us a Dual Points Distributor with the 1830 cap for the Electronic modification. He carelessly packed it in a small box, and it showed up here with the cap smashed. The 1830 caps should be handled with more care. Let's keep in mind they're aircraft parts.

    In the above photo, the screwdriver points to one of the two 8/32" screws that hold down the Points Plate. Shown here is the stock GM slotted screw. For years, I've replaced these with stainless Allen screws that are slightly taller. Builders need to be aware that some aftermarket distributor caps will not clear the Allen screws. This is easily detected because the cap will rock back and forth on the screws instead of sitting flush. Merely tightening the screws is not the solution. I have reverted to using slotted screws to prevent unobservant builders from replacing their cap with an incompatible one. The slotted screws will clear any cap I've seen.

    The above photo shows four point cams. Occasionally people ask if they can recurve distributors at home. It would be a very difficult process, and while you might achieve some results, a lot of the fine tuning we do to distributors is very difficult to see. Off the end of the screwdriver is the part of the point cam that the counterweight touches. Notice the four different profiles shown here. There are six different common Corvair profiles. The upper two are ground to match templates we've developed to produce ignition curves that suit aircraft use. The upper two point cams appear shinier because they're nickel plated, an ongoing test we're doing.

    A long time ago, I'd recommended Moroso Blue Max ignition wires. They're very good, but in recent years, I've come to prefer Accel 5041 sets. They have a tougher silicone jacket that holds crimps better. They're available in a variety of colors from www.SummitRacing.com. The set has enough wires to do the coils and 8210 also. Also in the photo is an MSD sparkplug crimper from Summit. These ratcheting crimpers cost about $60. But they're the absolute minimum standard for making ignition wires. $10 auto parts store crimpers are completely unacceptable for flight applications.

    We have a number of customers who have patiently waited for these developments with ignition systems so that they can have the most up to date pieces we produce. There are also a number of builders whose airplanes are closer to flying who've requested their orders be filled with Dual Points Distributors. We're equally happy to comply with either request.

    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

    November 2010 At The Hangar

    October 2010 At The Hangar

    August 2010 At The Hangar

    July 2010 At The Hangar

    May 2010 At The Hangar

    April 2010 At The Hangar

    January 2010 At The Hangar

    December 2009 At The Hangar

    November 2009 At The Hangar

    October 2009 At The Hangar

    September 2009 At The Hangar

    August 2009 At The Hangar

    July 2009 At The Hangar

    June 2009 At The Hangar

    May 2009 At The Hangar

    April 2009 At The Hangar

    March 2009 At The Hangar

    January 2009 At The Hangar

    December 2008 At The Hangar

    October 2008 At The Hangar

    September 2008 At The Hangar

    August 2008 At The Hangar

    July 2008 At The Hangar

    June 2008 At The Hangar

    May 2008 At The Hangar

    April 2008 At The Hangar

    March 2008 At The Hangar

    February 2008 At The Hangar

    January 2008 At The Hangar

    November 2007 At The Hangar

    September 2007 At The Hangar

    August 2007 At The Hangar

    July 2007 At The Hangar

    June 2007 At The Hangar

    April 2007 At The Hangar

    March 2007 At The Hangar

    February 2007 At The Hangar

    January 2007 At The Hangar

    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

    October 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

  • HOME  Zenair 601  Turbocharging  Thrust Testing  Engine 4 Sale  Oshkosh 2005  Sun 'N Fun 2005  Oshkosh 2004  Sun 'N Fun 2004  Corvair College #9  Corvair College #8  Corvair College #7  Corvair College #6  Corvair College #5  Daily Q&A  Flying Corvair Planes!  News  Mission Statement  Hangar Gang  Conversion Manual  Online Catalog  Maximum Horsepower  All About Corvairs  Corvair History  Engine Specs  Sonex Installation  RV Application  Why Fly Corvair?  FAQs  Liability Statement  Carb Ice  E-mail William 

    Copyright 2005 William Wynne Web Design by Aviatrix