Back when I lived in Minneapolis there was a great afternoon talk radio program called "Garage Logic". The tagline of the show was that anything worth figuring out could be solved out in the garage. There were running bits on the show...one of them was a rating for callers known as the "CI". The rule was you could count every internal combustion engine you owned, running or not, and add up all the cylinders. This was your Cylinder Index, or CI. Share your Cylinder Index!
When I played it on another forum in 2007, I came up with 290. Right now, it's only 71. I've downsized.
If I stick to just the ones that were installed in a vehicle, running or not, I come up with 158. I can't even begin to count all the parts engines and blocks I bought, swapped, traded, sold, etc without ever using them. But if you mean just right now, it's 12.
Sitting here on my porch can think of 57 that are running. Just remembered I gotta weed-eat today, make that 58 if it starts.
Just car, truck, and boat engines 176 if I didn’t miss any. If we start talking tractors, mowers. Trimmers and all the little 4 cycle do dabs that number goes up quickly.