what is this?
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Dan McEachern
Senior Member
Re: what is this? mag drive?
yes it is, but that mounting plate for the mag is way too thin!
yes it is, but that mounting plate for the mag is way too thin!
rotorwrench
Well-known member
Re: what is this? mag drive?
The gearing should be 1:1 for a mag or distributor and that gear looks smaller. It might be better suited for a governor of sorts or driving something else.
The gearing should be 1:1 for a mag or distributor and that gear looks smaller. It might be better suited for a governor of sorts or driving something else.
johnneilson
Well-known member
Re: what is this? mag drive?
It is an attempt at a side drive magneto
The gear is properly sized for a mag with 2:1 gear reduction or a governor
Most aircraft mags are 2:1 or crank speed.
J
It is an attempt at a side drive magneto
The gear is properly sized for a mag with 2:1 gear reduction or a governor
Most aircraft mags are 2:1 or crank speed.
J
rotorwrench
Well-known member
Re: what is this? mag drive?
All the Lycomings and Continentals I've ever worked on had cam driven mags. They use an idler on one to keep direction of rotation the same. Drive off the cam is 1:1 and the cam runs at half of crank speed. Radial engines have their own way of magneto & distributor function but all of them have to work for 4-stroke operation.
All the Lycomings and Continentals I've ever worked on had cam driven mags. They use an idler on one to keep direction of rotation the same. Drive off the cam is 1:1 and the cam runs at half of crank speed. Radial engines have their own way of magneto & distributor function but all of them have to work for 4-stroke operation.
Dan McEachern
Senior Member
Re: what is this? mag drive?
All vintage 4 cyl automotive magnetos- Bosch, Eiseman, Dixie, Splitdorff,Bendix, etc, with the exception of Wycos, run at crankshaft speed. These magnetos have a 2:1 reduction gear set built into the magneto in order to run the rotor at half crank speed. With that said, a side drive magneto on a Ford four banger uses a 25 tooth (crankshaft size ) gear on the magneto shaft. The cam gear in this instance is simply an idler for mag drive purposes. There are some distributor setups (Pierce Arrow/ Delco) that mount on the mag drive platform, but these have a 2:1 gear reduction in them to, again, run the rotor at half crank speed.
All vintage 4 cyl automotive magnetos- Bosch, Eiseman, Dixie, Splitdorff,Bendix, etc, with the exception of Wycos, run at crankshaft speed. These magnetos have a 2:1 reduction gear set built into the magneto in order to run the rotor at half crank speed. With that said, a side drive magneto on a Ford four banger uses a 25 tooth (crankshaft size ) gear on the magneto shaft. The cam gear in this instance is simply an idler for mag drive purposes. There are some distributor setups (Pierce Arrow/ Delco) that mount on the mag drive platform, but these have a 2:1 gear reduction in them to, again, run the rotor at half crank speed.