# why electromagnets aren’t used in piston motors, including internal combustion or not including internal combustion

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Will pistons specifically in the cylinder ever use electromagnets to propel the piston and to spin the driveshaft like gasoline motors?

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There are, in fact, vehicles that use electromagnets to drive the driveshaft of the vehicle directly, completely foregoing the need for pistons or combustion. We call these electric vehicles.

In order for electromagnet to function on such high temperature environment you need very high energy. That means that you net energy outcome from the system goes down since you need energy to overcome not only engine’s inertia but also to power the electromagnet now. Also what kind of function do you want the electromagnet to have?

Why make something move linearly to get rotation, when you can just skip that step and make it rotate from the start.

Pistons are just a crutch to convert explosions into useful motion, which you don’t need when you use electromagnets you can arrange in a way to get the motion you want directly.

There is no reason to have a piston if you’re not using internal combustion….the whole point of the piston / shaft is to turn the expanding products of combustion into rotational energy. The air gas mixture burns, expands, drives the piston up, and rotated the shaft.

In fact, having a piston going back and forth is very inefficient because you lose all of the momentum of the piston with every stroke.

There actually are applications of electro magnets in combustion engines. One example would be what bmw did with the vanos system. Basically solenoid driven valves to allow for computer controlled valve timing.

The whole package of the internal combustion engine is purposely to rotate the driveshaft.
It more straight forward to replace all of it with the electric motor instead of using the motor to move a piston.

I’m sure someone could correct me if I’m wrong but it’s an “Occam’s Razor” as pistons would lose energy themselves by virtue of more moving parts opposed to just cycling the driveshaft itself. It’s like adding a loop to a straight road, may look cool but the fastest soloution most optimal would be a straight line.

If you can use electromagnets to fire the piston, you can just put that energy to the driveshaft and skip the magnets alltogether. Can it exist, sure. Is it efficient on a mass scale, not at all.

Gas has way more energy per weight than batteries. Since we need combustion to extract energy from gas, pistons are the easiest design to utilize that. Introducing electromagnets would just add unnecessary power loss.

That said, we do have electric cars nowadays! Not nearly as much range as a gas vehicle of equivalent weight, but they certainly have their pros

Friction. The design of “traditional” electric motors is way more efficient than a piston and crankshaft arrangement like in an internal combustion motor. That design has a LOT of extra friction, necessary because of how internal combustion (ignoring turbine and rotary…) engines function.

Are you saying to use the magnet to drive the piston? Not like an electro magnet as a ignition coil or solonid or valve control? Many engines have electro magnets in them, but for things like fuel pumps etc. I think some also may use them for variable valve timing.

If you want the magnet to drive the actual piston, it’s just way less efficient than just having the electromagnet in a true electric motor. The while point of the piston is to compress gas/air so you can blow it up. A electric motor is much more efficient in turning a shaft directly instead of driving a piston.

because if you’re using electromagnets, you can just drive the wheels directly. an electric motor’s job is converting electricity into rotation. there’s no need for pistons.