A short code for a Honda engine. It's the engine that you'll find in your stock 94-01 Acura Integra GSR. It's mostly known for having the best thing ever made, VTEC, compared to it's counterpart without VTEC, the B18B (94-01 Integra LS). You can find the code printed on the front of the motor, near the transmission, along with the engine's serial number.
My GSR has a fully built B18C1.
So what? My integra is stock and still has a B18C1. VTEC FTW!