For drive power?

An alternator can charge a battery and run accessories, but given 1 horsepower is roughly 730 watts, you really need some high voltage system to keep the magic smoke in.

Edit: maybe we're talking different things. Honda used to integrate electric motors directly to engines in their early hybrids. Ford, iiiiif I recall, combine engine and electric power in the CVT transmission.

Both can use the EV motor as a massive alternator, but a standard alternator is simply too small, and attached to the engine too weakly, to generate the power of a hybrid.

What are you talking about?

I suspect we're talking past each other.

If you're talking about the Chrysler/Jeep electric motor boost thing, that's not new - Eaton has made them for going on 30 years for semis.

But retrofitting... Look at the torque loads you're talking about. And the space required.

For example, starters use a lot of current and generate significant torque, for seconds at a time. They overheat quickly. Trying to retrofit a more capable electric motor would be a huge task. Hell, simply removing the starter on some V8s requires detaching a motor mount and lifting the engine, there's so little space.

It would be even worse for the alternator (which would really revert to using a generator). You'd have to reengineer the crank pulley setup (basically give the crank a mount plate like the rear does), as the key design is intended as a shear relief. And that means all new pulleys, etc. Take a look at what's required to install a an aftermarket supercharger on a V8, say for racing. And the street versions don't require the torque loads you're looking at with a useful generator.

To do this aftermarket, it would require being engineered on a per-engine-platform basis, at a minimum, and then also per vehicle, as space constraints and mounts vary so much.

Then looking at that cost, and materials, battery, cables, etc, there are better ways to spend money and resources to achieve, what exactly?