Topic: Sandcast engine preferences/ cool engine pics./ magneto talk

[BomberMann650]

What makes a magneto function?

[754]

Has built in magnets,and internal coil, actualy has like a mini distributor plate inside. But no external. Coil or power source, needed for it to work.  Drawback is fixed advance, can be harder starting. . I have not tried one yet, but Bill P is running one and reports no starting issues.
 Some mags do have advance mechanisms, and impulse start, but this does not.
 On some like Morris Magnetos (not the wheel maker) the mag could rotate on a swivel base to preset stop..at advanced position, then upon starting, would move back to running position.(aided by springs or your hand. On early bikes like Indian and Harley and most others, there was left side twist grip to retard the mag for starting.
 So if your battery dies, or falls out or breaks, you can still ride it home...

[BomberMann650]

I heard legend of the extra twist grip for timing, but i didn't know it was for cold start purposes!  Thanks for sharing the knowledge frank!

[754]

Actually the early controls dont use a cable as you know it.
Its a coiled outer with a stiff piano wire inner,  like a lawnmower cable.. Whizzer used the same thing. So the cable stays where you left it if you let go, no need for cruise control.
 Sad day, when you dont learn something..

[Don R]

 Cool engine Frank, The early mags sometimes needed the magnet re-magnetized.  My Chevy vertex barely made a spark, it needed serviced and I called Joe Hunt mags, it was after Joe passed away and I think I caught them on a bad day. I sold mine at a drag race.

[754]

Them big Vertex mags on fuelers take a lot of Hp to turn them..

[Don R]

 Most of them use MSD mags now, I think you're correct on using lots of hp to turn one. It's amazing with dual 44 amp mags and two plugs, a cylinder can still go out. They put ground cables on the heads so the plug doesn't fire to the piston top, crazy.
 David Leahy, a guy from here makes a lot of electrical parts for the nitro  guys. He makes the shutoff system that kills the ignition, fuel and deploys the chutes. He also makes some of the timers that control timing, clutch and fuel volume. 

[01Thomas]

The big advantages are:
A. no external power source needed and
B. the faster the engine speed the stronger the spark.
This is why magnetos are/were used extensively on aircraft with reciprocating piston engines.

Has built in magnets,and internal coil, actualy has like a mini distributor plate inside. But no external. Coil or power source, needed for it to work.  Drawback is fixed advance, can be harder starting. . I have not tried one yet, but Bill P is running one and reports no starting issues.
 Some mags do have advance mechanisms, and impulse start, but this does not.
 On some like Morris Magnetos (not the wheel maker) the mag could rotate on a swivel base to preset stop..at advanced position, then upon starting, would move back to running position.(aided by springs or your hand. On early bikes like Indian and Harley and most others, there was left side twist grip to retard the mag for starting.
 So if your battery dies, or falls out or breaks, you can still ride it home...

[BPellerine]

they do throw a good healthy spark,and you can kickstart them ,but maybe not full advance on a big inch motor with high compression.bill