Our Midget race car project has opened up several doors to the overall motorsports experience. Previously, we had little experience with magneto ignition systems, but we needed to get up to speed quickly. In our pile of parts we pulled out a vintage Scintilla magneto and started down the path of discovery.
A quick internet search led us to Taylor Cable Products, the manufacturer of many high-performance ignition and battery components for motorsports. The company also makes the Scintilla Vertex magneto. So, we reached out to Susan Weimar and Justin Askren at Taylor Cable to help us understand what we were dealing with. As it turned out, we had a lot to learn.
We took a snapshot of the data plate on our magneto and asked if they could help us figure out what we had, and what we were going to need for our project car. What we ended up with was a grade-A education on the topic. If you are big fans of motorsports history and want to know more about magneto ignition systems, read on!
The humble, but very reliable, magneto ignition system has stood the test of time for well over 100 years, and is still used in high-performance applications today. In aircraft and high-performance racing engines where a dependable hot spark is needed, magnetos are the solution. These ignition systems work best when size and weight restrictions limit other types of ignition systems powered by an external battery.
The best description of a magneto ignition is simply a distributor and generator combined in one single unit. Unlike a typical distributor ignition, the magneto creates energy for a spark without an external electrical power supply. In this regard, a magneto is an electrical generator. Using a series of rotating magnets that break an electrical field to charge the primary circuit, then transfer the current charge to secondary windings. The number of windings in the secondary circuit are greater than the primary circuit, the current is multiplied in the secondary windings.
The multiplied charge produces a spark with higher voltage – as much as 20,000 volts – a hotter spark than conventional distributors can produce. First introduced on the 1899 Daimler Phoenix, several other car manufacturers followed shortly after. Even after 120 years, magnetos are still being made for motorcycles, performance, and classic cars with very little change.
The Scintilla magneto has roots back to the World War. Not the second one, which spawned many technological advancements, but the First World War in 1914. World War One is where aviation first saw major involvement in military conflict. With the increased use of aircraft, the allies wanted their aircraft to be as reliable as the enemy’s airplanes. “They contracted with Swiss engineers to create a magneto that was as good as the ones being used by the Germans,” Justin states.
The magneto was named Scintilla for the brilliance of the flashing sparks it produced. Scintilla had a number of divisions within the company. Many of these divisions have gone on to great things, like the Vertex magneto division. Their power tools division is now the Bosch Power Tool Corporation.
The aviation and automotive magneto divisions were completely separate. Scintilla aviation magnetos produced for the war effort were manufactured in Sidney, New York, and were immediately adopted by Wright Aeronautical Corporation, Curtiss Airplane Motor Company, and Pratt & Whitney Aircraft.
The new automotive magneto design proved itself through the war in tanks, trucks, and other military vessels. The Scintilla magneto was credited with contributing to the reliability of these military vehicles. At the same time, Scintilla’s aviation magnetos became known as “The world’s most trusted name in ignition” in the aviation industry. Even Charles Lindberg made his historic Trans-Atlantic flight in 1927 with two Scintilla magnetos providing the spark for his engine.
Scintilla Vertex Magnetos
Scintilla Magneto Company was producing 10 magnetos a month at the end of World War One. In 1929, the Bendix Aviation Corporation purchased Scintilla’s aviation magneto division, adding this division to their group operations. This separated the Scintilla aviation and automotive magneto manufacturing into two unique branches. By January of 1942, the production rate of Bendix and Scintilla magnetos had grown to 17,000 a month. Things continued like this through the 1970s.
During the period of public company takeovers in the early 1980s, the Bendix Corporation attempted a hostile takeover bid of competitor Martin Marietta, who in turn launched its own takeover bid of Bendix. United Technologies joined the fight, supporting Martin Marietta in its takeover bid. Bendix was rescued by Allied Corporation in 1983, and later merged with Honeywell, with the Scintilla aviation magnetos becoming a Honeywell brand.
The Scintilla automotive magnetos prospered under the Vertex name and became well known by automotive enthusiasts. Hundreds of thousands of the Vertex magnetos were sold world-wide, many to automotive companies like Volkswagen.
Engines equipped with the Vertex magnetos were used as industrial equipment due to their dependability and low maintenance requirements. While most combustion engines of the time were built with contact breaker points which required routine maintenance, the Vertex magnetos were virtually “hands-off.”
Many of these units were sold under the F. T. Griswold Mfg. Co. name during the early 1950s. Griswold was an exclusive distributor in the United States, and had over 75 different applications for the Vertex magneto. They also sold a Vertex relay switch that bore the Griswold name. Boat enthusiasts with flathead Ford engines bought the Griswold Vertex magnetos in record numbers for the time.
According to company literature, Ronco Corporation of Blue Bell, Pennsylvania, obtained the sole distributorship for the Vertex automotive magnetos in the U.S. in 1953. This is exactly the same time when racers and hot rodders were finding magnetos as a valuable ignition system for their high-performance engines.
The company experienced tremendous growth, and by 1978, the entire manufacturing operation was transferred to Ronco Corporation because of the high demand from motorsports. Vertex Performance Products was formed as a division of Ronco in 1988, where it operated as a separate entity in Oreland, Pennsylvania.
Vertex Performance Products was acquired by Taylor Cable Products in 1994, where the magnetos continue to enjoy a strong reputation in the world-wide market of high-performance racing engines, boats, aircraft, and rugged industrial engines.
What We Have
We went through the history of the Vertex magneto because it is important to understand how many variants of the magnetos were manufactured over the decades. Many of these are still in service today, which is a statement of their durability and design. As with any product purchased over the internet, it is vital to identify the part you are working with.
From the photo of the data plate we sent to Justin at Taylor Cable, he was able to tell us our magneto was an original Scintilla Vertex unit built in Switzerland. He could tell because the data plate had a model number and not a serial number on the tag. “Our serial number log goes back to 1953, but only for the U.S.-built Ronco units,” he explains. “This unit was most likely used in some type of industrial engine since it has a speed limiter. My best guess on its age would be sometime in the 1960s.”
According to Justin, the blue cap is not an original piece with this unit. The originals were tan color and the blue caps are from the Ronco era (mid/lat- 1970s through late-1980s). He also explained we could probably use this magneto, but he strongly advised to have it serviced and remove the speed limiter for racing. He also pointed out the timing advance will probably need to come in earlier for our purposes.
Much like a conventional distributor, timing is critical when using a magneto. The timing advance, which allows the engine to start easily, is not the same as the advance timing necessary to make the magneto work at its peak at higher rpm.
Here is the breakdown of our data plate:
Model # – Description
O – Vertex type magneto
A – Internal construction
P – Speed limiter
4 – Cylinders
L – Rotation (left hand)
4 – w/o radio shield, w/o impulse start, w/ advance
02 – Shank diameter / length, w/ oil return groove
Z144 – Engine / base type
0° advance @ 800 crankshaft rpm
25° advance @ 3,500 crankshaft rpm
1,900 – speed limiter rpm 3,800 crankshaft rpm
Stay tuned as we will follow up with care and maintenance of magnetos, as well as an in-depth article covering factory service of our magneto as it goes through inspection and repair at the Taylor Cable facility.