Off Topic: For those of you who love Magnetos!

[Bored&Stroked]

I've been going through all the ignition electronics for our FlatCAD Bonneville engine. It is a blown/injected 1940 Cadillac flathead - running Alky. Every part of the engine (except the block) is something we designed . . . most of it we built as well (heads, lifter blocks, roller lifters, girdles, etc). It makes 650 HP on the dyno.

Anyway, I've needed a way to test the complete MSD ProMag system. It is a ProMag 20 amp unit and the magnets are so strong that you cannot use a Sun type distributor machine to turn it. So, I needed to come up with an inventive way to do my testing.

I decided to create a "Frankenstein Test Bench" - using my lathe to drive the unit. Had to make the fixtures to hold it, the hub to mount the crank triggers, the spark plug rack, etc..

Anyway . . . here is ole 'Sparky' on my lathe, with a link to a video of it running:

Video: https://www.instagram.com/p/DSa9V6KkgSL/

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[Mart]

Blimey that's quite a machine. I wonder if there is a tipping point where the power to drive it negates the extra power gained by using it.

[petehoovie]

Originally Posted by Bored&Stroked

I've been going through all the ignition electronics for our FlatCAD Bonneville engine. It is a blown/injected 1940 Cadillac flathead - running Alky. Every part of the engine (except the block) is something we designed . . . most of it we built as well (heads, lifter blocks, roller lifters, girdles, etc). It makes 650 HP on the dyno.

Anyway, I've needed a way to test the complete MSD ProMag system. It is a ProMag 20 amp unit and the magnets are so strong that you cannot use a Sun type distributor machine to turn it. So, I needed to come up with an inventive way to do my testing.

I decided to create a "Frankenstein Test Bench" - using my lathe to drive the unit. Had to make the fixtures to hold it, the hub to mount the crank triggers, the spark plug rack, etc..

Anyway . . . here is ole 'Sparky' on my lathe, with a link to a video of it running:

Video: https://www.instagram.com/p/DSa9V6KkgSL/

[Scotty's 52 F3]

Great idea. I wouldn't want to get zapped by that unit.

[GB SISSON]

Dale, I DO consider myself as a lover of magnetos. I have messed around with them for almost 50 years on old tractors and a lot of one lung stationary engines. Never the go-fast type like yours. I have read about them in Clymer's 'How to hop up the Ford V8', which was one of the first books on the flatheads I owned. Your driver is very ingenious, and I too would insulate myself against it. I have owned mags that will jump a fat blue arc a considerable distance and my cardiologist (who's working on a '47 Hudson convertible' says to keep my distance from magnets and high voltage on account of my pacemaker. Sticking with my battery-coil-points for now. How does this mag of yours advance and retard? Lever on the coulmn?

[rotorwrench]

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I spent an entire career working on engines ignited by magnetos. It's sort of a love hate relationship. I love how they work for the most part but I didn't like the difficulty level in removing and reinstalling them. Aircraft still use them and they are reliable within the recommended overhaul time and date periods. None of them run anything but full advance with starting aids to get the engine started with a retarded spark. Due to this, they have no load control. The Scintilla/Vertex automotive type is about the only one that has a semi automatic advance system. Some of he motorcycle mags used back before electronic ignition were cable adjustable for spark control but they were mostly the Lucas performance types.

[Flathead Fever]

I'm still having magneto flashbacks fifty years later. I had picked up the neighbor's magneto for his drag race mustang and spun it. It zapped the crap out of me. I was a kid and couldn't understand how I had been electrocuted by something that wasn't hooked up, no wires, nothing.

[Bruce of MN]

Not magneto, but I took an auto mechanics night school class as a HS sophomore. The teacher had a jeep ignition system with battery display and I wanted to see the rotor rotate. Boy, did I get zapped when I spun the dizzy shaft while holding the cap!

[37 truck]

Had a Lucas magneto on a 1958 Triumph Trophy, really threw a spark and was more reliable than points.

[tubman]

While we're into "war stories", I'll add my experience. The first couple of years I had it, I ran my dirt modified with the '54 331 hemi stock. After I spun a bearing, I lost my mind and went overboard on the engine : 12.5:1 pistons, Engle roller cam, Donovan forged rockers, ported heads, the whole deal. I kept the stock Chrysler distributor since it was a dual point, just freshening it up and adding a "racing coil". Over the next couple of years, I experimented with induction systems, a 4 BBL, 4 97's, a 500 cfm "dirt track" Holley, and ended up with two Large base 2G's. It never seemed to have the "snap" I was looking for. After a couple of years, I found a Cirello "Frankenstein" magneto. What a difference! It woke the engine right up. My theory is that the stock points ignition wouldn't fire through all that compression at high RPM's.

A year or two later, I had the opportunity to speak to one of the owners/builders of the car. He told me that they had a similar experience with the car back in the '60's when it was built. They had spent a ton on the engine (including a trip to California by one of the owners to consult with Ed Iskenderian for a special cam), and the Olds Rocket that was in it just wasn't what they expected. They installed a magneto, and the car became track champion at a number of tracks and won the Minnesota State Stock Car Championship in 1965 and 1966. (The definition of stock cars has changed a bit since then.)

[petehoovie]

[Bored&Stroked]

Good post Tubman! In my experience with the FlatCAD, we switched over from a Vertex Magneto to the ProMag. We're throwing a lot of fuel at the motor --> 8 nozzles in the hat and 8 down-nozzles in the manifold ports. We originally ran a hopped-up Vertex with rare-earth magnets and about 4 amps of output.

When we put the ProMag 20 on, there was a very noticeable change in how the motor sounded . . . just a different beast. Having a lot of spark energy (duration and spark energy) to light the fuel is surely a good thing!

[rotorwrench]

I remember when the GM HEI distributors came out. Those were the first ones that I can remember being able to hear the spark events with the engine running. It was when the spark jumped from the rotor to the cap during each high tension release.

Aviation is just now getting approvals for electronic trigger fired mags. The breaker points are eliminated but they still have rotating magnets. This will eventually allow for load control when they prove reliability. Everything in aviation has to prove how long it will last. Bearings used to last the overhaul limit of the engine but that eventually went out the window with higher TBOs. Some brands are limited to 500 hours and some still have 1000 hour limits. Nothing lasts forever in that business.