Steam Engine or maybe Air Engine

Since it looks like the first Electric Lemon is being built no need to continue thinking about that.

Since that is done it leaves the 3 type of classic car power plant. The gasoline engine is extremely well represented. The electric car is on its way. That leaves it for someone to build the steam powered car. For that I give you this beauty.



That is referred to as the Z8 created by Robert Green and found at Green Steam Engines

This engine is designed to be used as a generator but there is no reason it couldn't be used to power a car. The engines vary from 2 cylinder to 16 cylinder models and at least according to the site the power can be in the hundreds. I wouldn't expect the hundreds to be that massive but with a light car it could still work out well.

There are some disadvantages to steam. You need to keep adding water, and it will take a while for the water to heat up enough to turn to steam. You also will need heat the water, and all of that would add weight to your light car to make it not so light. However you don't need to run it with steam. You can run it off air. So instead of connecting all this to a boiler you just need to connect it to an air compressor which when you inevitably break a line you'll just blow air all over the place opposed to really hot water.

Plus as an added bonus these engines all seem to sound like a regular car engine about to have a major failure.



Now there are other options like the 9 cylinder Radial Steam engine

And here is even a radial model that someone already made run on air.

And I'm sure many other types of steam engines someone could use if they look into it. Now we just need someone daring enough to try it.