As you may have noticed, the 8.2L Detroit Diesel sounds sorta similar to the T444E and the MaxxForce 7 (depends what bus you're hearing it in though). Enjoy the sound of history! Cuz you don't hear these engines that much anymore nowadays. Sadly the bus I recorded in 2-5 got retired as of last year. 1-5 were recorded off of 1990 Thomas Chevrolet C60's, which one was a short bus and the other was a full-sized bus. The full-sized one was the one that was retired. 6-7 (No joke intended!) were recorded off a 1987 Thomas Ford B700, which you may noticed sounds different with that engine compared to a C60 (it's just revving in #6, btw). Sounds more like a T444E and a 7.3L IDI in a B700, tbh, especially since diesel-powered B700s are such aggressive-sounding buses (and I published this project at 4:44 PM, fun fact. lol) And these didn't have backup alarms, btw.
Credits: * Google Maps for the image.