Nomenclature
The B21, and related red block motors, were named using the following convention: B##X or B##VX. Where B stands for "bensin" (gasoline), ## stands for the displacement in decilitres, and X is an appropriate suffix. On the later low-friction motors, V denotes SOHC configuration (0) or DOHC configuration (4, for 4 valves per cylinder).
i.e. B230 (SOHC, 2.3 litres), B234 (2.3 litres, DOHC * 4 valves per cylinder * 4 cylinders = 16 valves)
The following suffixes were commonly used by Volvo:
- A - single constant-pressure type carburetor (such as the Pierburg 175 CDUS), typically with manual choke
- B - high compression, with twin carburetor's, either twin zenith-strombergs or twin SU's.
- E - high compression, no catalyst, mechanically fuel injected k-jetronic
- BxxET - K-jetronic turbo
- B2xxET - Motronic controlled electronic fuel injetion, turbo.
- F - low compression (9.8:1 on B230F, 9.5:1 on B280F, 10.0:1 on B234F and 10.7:1 on B6304F), USA/Europe version (F for Federal) with catalytic converter. Europe/APAC version, fuel injected (usually LH Jetronic or Bendix Regina)
- K - single jet type carburetor (such as the Solex-Cisac carbs), typically with automatic choke
- G - LH2.4 Jetronic but without cat. converter, CO adjustment on the AMM (similar to LH2.2 Jetronic). Some models without O2 sensor, others with O2 sensor which requires regular replacement at intervals due to lead fouling. For markets which unleaded fuel was rare in the early 90's, e.g. Eastern Europe
- FB - low compression version of B230F (9.3:1) with the "531" cylinder head and VX3 camshaft, power output 11 kW (15 PS; 15 hp) and 2 N·m (1.5 lb·ft) more than B230F. LH2.4 Jetronic fuel injection, for European markets.
- FD - essentially a B230F fitted with Exhaust Gas Recirculation (EGR) and Pulse air system for cleaner emissions
- T - turbocharged, after E or F suffix (example: B21ET, B230FT)
- FK - low pressure turbo, 1995 onward, not supplied in North America. Identical to the B230FT engine of that time but lowered boost level (4 PSI)
- FT - LH-jetronic 2.2/2.4 Turbo
- FTX - Higher power output B230FT (approx 190 hp)
Read more about this topic: Volvo Redblock Engine