William Wynne

"The Corvair Authority"

Remanufactured Dual Points Ignition Distributors for Corvair Conversions

I offer two different Distributors for the Corvair conversion. Our traditional Distributor has two sets of points. I have produced these for more than 10 years, and the majority of Flying Corvair Aircraft in the World have one installed. Since 2007, I have offered a fully flight proven Distributor that has digital electronic ignition on one side and points on the other. This evolution is now flying in more than 20 Corvairplanes. Both versions capitalize on my decades of experience with the Corvair and are custom tailored for smooth, reliable operation with All of Our Other Products. This original Remanufactured Distributor, Part No. D-1, is a precision built and thoroughly tested unit. It provides reliable Dual Ignition for Corvair flight engines. There is a summary of my years of flight testing Corvair ignition systems through this evolution in the June 2003 issue of Kit Planes magazine. This Distributor represents the ultimate points evolution of my work.

The Distributor housing is thoroughly cleaned and then machined for a second oilite bushing at the base. With two bushings, the shaft is stabilized, effectively eliminating dwell variation. These bushings are line bored to be in perfect alignment. The main shaft is polished in the bearing area and shimmed to minimize play. The mechanical advance is modified to give the full advance required for the horsepower potential of the engine to be tapped. Light weight springs allow the advance to come in far faster than any automotive application. This allows the full advance to be checked while the engine is running at full static rpm, a crucial safety issue. My unique stainless steel points plate is installed on each Distributor. This precision, CNC manufactured plate mounts two sets of stock Corvair points exactly 180 degrees apart. I install two CS788 points sets, lubricate them, then install brand new caps and rotors with all brass contacts.

I personally test each Distributor on my 1960 model Allen Tune Up distributor machine. I check the dwell, timing symmetry, start rpm, stop rpm and total advance. Finally the Distributor is given a test run to 5,000 rpm to verify that it is free of point bounce and shaft chatter. The Distributor with cap and rotor weighs 2 pounds, .5 ounces.

Please print, complete and return a Liability Statement with all orders. These are available for printing at the Liability Statement Page.

Thank you for your order.

Installation Instructions for Remanufactured Dual Points Ignition Distributor

Thank you for purchasing a Remanufactured Distributor, Part No. D-1. Your purchase makes possible my continued research and development on the Corvair. In this way, youíre investing in the future development and perfection of your chosen motor.

These notes are supplementary to my most current Conversion Manual. This Distributor is developed as part of the system that we use to convert aircraft motors. This system is outlined in the Conversion Manual. The parts alone, without the information contained in the Manual, will not allow you to develop as reliable an aircraft conversion. When I develop and market a part, it is fully flight tested, and designed to work in concert with the other parts in the conversion. I take into account the way that most people are capable of installing and operating the part. Thereís a great deal of consideration that goes into these issues, and I urge you to utilize all the information in the Manual and the parts in the way that they are intended to be used. Of course, contact me at any time with any question you may have.

To be fair, everyone needs to understand that these are not certified parts, and it's not a certified motor. Experimental is not a misnomer; everything we do in this field is of increased risk. If anyone even suspects that they have a problem, E-MAIL or CALL ME. If you have never worked with torque wrenches and precision fasteners, get help from an A&P. Let's all remember to use our heads and not take unnecessary risks. I have gone to great lengths to make these components as reliable and easy to install as possible within the bounds of affordability. I have personally flown all of these parts, because I have a low opinion of people who market aircraft parts without flying the parts themselves. I believe that each and every part I sell is the best solution to its respective aspect of converting a Corvair engine. Take your time and do good work. The system is proven and will reward you with the same type of reliable flight performance we have always had.


A rebuilt and recurved Distributor is the heart of a good running aircraft conversion. I have doubled the climb performance on aircraft which were previously operating with a distributor as removed from a car. Your overhauled and modified Distributor will provide peak performance.

On the underside of the Distributor, there is a number of degrees and rpm written, for example, 20-2,500. 20 represents the amount of degrees in crankshaft revolution that the Distributor will mechanically advance. In this case, if you wanted 30 degrees of total advance, you would set the timing at idle to 10 degrees, and as the RPM increased, it would advance 20 degrees for 30 total. It would reach its full advance at 2,500rpm. The motor will hold 30 degrees total at all rpm above this. I test them to 5,000rpm. It is important that all the advance be in before the propeller reaches its static rpm. This way, you can check the full advance with a timing light with the engine at full static rpm on the ground.

Engine ready for Distributor installation.
1.The #1 sparkplug is the one closest to The Distributor. Remove it from the engine and put your finger over the hole. Rotate the engine in its direction of rotation until you feel compression. Watch the balancer for the Top Dead Center (TDC) notch to align with the timing marks. The engine is now at TDC on its compression stroke for #1 cylinder.

2.The marks on the Corvair case show 0, 8 and 16 degrees Before TDC. The length between the 0 and 16 degree marks is .950". Two times this length from the timing notch should be marked on the balancer as 32 degrees BTDC. It is a simple matter to mark the balancer with a silver Sharpie.

3.Rotate the engine slightly so that the balancer TDC mark is aligned with 8 degrees on the case.

4.We always install The Distributor so the notch cut in its plate faces the centerline of the engine. If you're standing beside the #1 cylinder head facing The Distributor, this notch will be in the 12 o'clock position. With The Distributor cap off, there's an empty screw hole visible in the 11 o'clock position. We always set the plug wire terminal in the 10:30 position as the #1 terminal.

5.Look down The Distributor hole with a flashlight. You will see the slot in the top of the oil pump shaft which is driven by the tang on the bottom of The Distributor. This slot needs to be aligned with a long screwdriver until it runs from the 11 o'clock to 5 o'clock position.

6.Make sure that you have a gasket beneath The Distributor. Insert The Distributor in the rear accessory housing. Hold the plate notch at 12 o'clock and make sure the rotor is pointing at 10 o'clock. As The Distributor drive gear begins to engage the crank gear, the rotor will move slightly clockwise. If you have it timed correctly, the last 3/8" of downward travel will smoothly engage the bottom distributor shaft tang with the oil pump drive. If it does not drop in smoothly, lift out The Distributor and realign the oil pump drive with a screwdriver.

7.The correctly installed Distributor will have the rotor pointing very close to the #1 terminal. Verify that the balancer mark still points at 8 degrees.

8.With a multi-meter or test light, check for a circuit through the closed points. You can ground anywhere on The Distributor Plate, and put the positive lead on the points terminal. Rotating The Distributor body while examining the points closely will show you the points just opening as your meter or light shows the circuit opening. This is how a points system works: The opening points collapse the field in the coil and send the high voltage spark on its way. When you have it set so this occurs when the TDC mark on the balancer is aligned with the 8 degree setting on the case, you have the ignition close enough to fire up on the test run. Put down the distributor clamp and secure The Distributor in this position.

9.Reinstall The Distributor cap, being careful not to pinch any of the wires. In the photo above, my fingers are touching the #1 sparkplug lead. Moving clockwise, the firing order is 1-4-5 2-3-6. Notice that we always set up the sparkplug leads so there's room to remove the cap without having to pull the leads from it. This is one of the many small details I've learned and included in this Web site, my Corvair Conversion Manual and 601/Corvair Installation Manual that make some engines easy to inspect and maintain.

10.When you get ready to start your engine for the first time, you absolutely, without exception, must use an automotive timing light to set the final ignition setting. In this case, the 8 degrees is referred to as the static advance of the engine. In flight, you're concerned with the total advance of the engine. The total advance is the static advance plus the centrifugal advance I've built into your Distributor. This varies from unit to unit, and is part of the reason why I test them all individually to ensure each centrifugal advance is within limits.

11.The easiest timing light to use is a model with an inductive pickup, like they sell at Sears. The inductive pickup is a clamp that goes around the #1 sparkplug wire, which will trigger the strobe in the timing light. If you've never used one before, any automotive mechanic can show you how they work. The engine should start almost immediatetly on the static setting. Once it's thoroughly warmed up, the actual timing of the engine can be set. With the tail tied down, and a competent pilot at the controls, the rpm of the engine must be raised to 2,700 rpm. In most Corvair powered aircraft, this is near the full static rpm of the propeller. This is the point where the timing is checked with the timing light. Countless dyno runs and hundreds of engine builds have taught us that the great majority of Corvair powered planes are best served by 32 degrees of total timing advance. They make expensive digital timing lights which can automatically calculate the 32 degrees for you, but I never use one of these because some are equipped with switches for the number of cylinders in the engine, and others have very vague timing scales. You're best off with the simplest timing light, and using the 32 degrees you already marked on your balancer. When the timing is correctly set, the 0 mark on the case will line up with the 32 mark on the balancer when you hit it with the timing light at 2,700 rpm.
WARNING:Corvair ignitions as I build them are extremely powerful. NEVER touch The Distributor cap or wires on a running Corvair engine. Although the possibility of being surprised with a 40,000 volt shock is low, it happened to a builder in Australia, and the involuntary jerk of his body put his other hand in contact with the turning test club prop. He was very lucky to escape in as good a shape as he did. When adjusting the timing, stop the engine to turn The Distributor and then restart.
WARNING:These Instructions apply ONLY to This Distributor. Stock Corvair car distributors have very stiff counterweight springs inside. They will frequently add 8 or 10 additional degrees of advance above 2,700 rpm. Distributors not verified on machines to a specific rpm could easily destroy your engine by sending it into detonation when the rpm picks up in flight.

These are not new recommendations. There are many references on FlyCorvair.com to checking timing with a timing light. You can Google [TM] it in the box at the bottom of Our Home Page. A careful look through our Web pages will show you how frequently we use them with the dyno. Every 601 Installation Manual we've sold includes a photo of Gus and I performing this operation on our 601. Manuals I wrote as far back as 15 years ago contained capitalized warnings about flying any engine you might even suspect would detonate.

The Number One cause of detonation in Corvair powered aircraft is careless builders setting the static timing, but neglecting to check the total timing with a light. Remember that you cannot hear detonation in most aircraft. And it's possible to damage a Corvair engine even in a 2,000 rpm ground run with excessive ignition advance. Engines that "sound good" to most builders from idle to 1,500 rpm frequently have 10 or 15 degrees too much ignition advance. Opening the throttle to takeoff rpm on these engines would send them into detonation. 32 degrees has a reasonable factor of safety built in. We've tested engines in idealized setups with timing far advanced beyond this. However, new engines that are run lean or on auto gas or have unproven cowlings have very little margin of safety against detonation.

If you have any questions at all when installing The Distributor, please call. Iíll be glad to spend the time to get your questions thoroughly answered. Remember, safe practices are paramount. By choosing a Distributor with my Points Plate, which has hundreds of hours of proven flight time on it, and is made of the best materials, you have taken a giant step toward minimizing the risks associated with ignition systems. Thank you for your purchase and congratulations on your good judgment.

Your purchase of parts like The Distributor offered through www.FlyCorvair.com makes possible my continued research and development on the Corvair. In this way, youíre investing in the future development and perfection of your chosen engine.


HOME  Zenair 601  Daily Q&A  Flying Corvair Planes!  News  Who Is William Wynne  Conversion Manual  Manual Photos  Online Catalog  Maximum Horsepower  All About Corvairs  Corvair History  Engine Specs  Sonex Installation  RV Application  Why Fly Corvair?  FAQs  Technical Support  Links  Liability Statement  Carb Ice 

Copyright 2018 William Wynne Web Design by Aviatrix