Let's say I have a small car with a 4cyl engine, is it possable to put a smaller engine in the car?

Question

The orginial engine is around 1500 cc and 100 hp. Manual transmission and small lightweight body car. Can a engine around half of the displacement or hp be put in the car, adapted to move what needes to be moved and still be useable? It is understood that performance with suffer. I have seen three cyl engines that produce 50 hp and V twin engines that can produce around that as well. They have a standard pole that sticks out of them and could be welded or bracketed onto the necessary moving parts of the transmission and for belts etc.

Answer 1

It sounds a real kludge.
A smaller engine would require a different set of gears since a properly designed drive train lets the car run at common speeds.
The smaller engine would have to be run at higher rpm's for the same power delivered to the road and thus would use more gasoline than expected. Instead of a 50HP motor using half the gas of a 100HP, it might use 2/3's.
And break sooner.

Answer 2

100 hp in a 1500 cc engine?
Likely its a sporty car, right?

You can check if the standard version -of the same car-, has a smaller, less powerful engine.
This is the most recommended engine swap, as it will fit perfectly.

For other engines, you have to check your car weight, and the gearbox/differential gear ratios, and compare them to the car weight/ gear ratios of the smaller engine; to find out if the smaller engine will move the car.

Be aware that a too small engine, can use more fuel, if forced to move a too heavy car.

Answer 3

I'm guessing you're doing this for fuel economy. It won't work.

A common misconception is that small engines are guaranteed to get better gas mileage. A 1000cc 2 cylinder motorcycle engine is techinically smaller than what you have now, and would probably be far less fuel efficient.

Answer 4

Get a 26 hp Kohler. That will move you around.