Originally Posted by A Future Pilot
What exactly do you mean by "13 series"? Is that the raptor engine?
No, it's just the two first characters of the serial number and designates the displacement as 13 cubic inches. These are just run of the mill motors we saved from the junk pile. Most are aluminum bore with bushing cranks, but they run pretty good. By the time we clean up the ports and up the compression a little, it adds some power.