B18C1 = 170 hp 1.8 liter VTEC ('94-'01 GSR)
B16A = 160 hp 1.6 liter VTEC (JDM models: Civic SiR, Civic SiR, Integra RSi, Integra XSi, CR-X del Sol SiR; USDM Models: del Sol VTEC, '99-'00 Civic Si)

Incidentally, the '90-'93 Integra RS/LS/GS motor was the B18A. And generally when someone wants to refer to a Type-R motor they will call it a B18C5 or B18C-R.