Wentward Question

The Wentward Bus is amazing. The engine sounds and looks great. It seems like a Deteroit Diesel. When I was looking at it, I happened to notice there is a small silver-colored Y-Shaped thing attached by a crankshaft pulley belt to the main engine. I thought this was a small V-Twin Cylinder engine, like one in a motorcycle. I think this smaller engine is to power the batteries. What do you think?
(sorry for the low graphics my computer can only run that)

 

That is most likely a positive displacement air pump for the air suspension and other systems that run on compressed air.

 

its a compressor according to the .dae file

 

Huh, I thought it was the starter engine; many big diesels from the time period used a small 2-stroke engine to get the crankshaft of the big diesel moving.
Video of what I mean:

Edit- looking at the wires it doesn't connect to the main engine, and the start up sound doesn't sound like it would be so it's definitely the air compressor, as stated above.

 

YO DAWG, I HEARD YOU LIKE STARTER MOTORS, SO WE PUT A STARTER MOTOR FOR YOUR STARTER MOTOR, SO YOU CAN START WHILE YOU START.