Volvo Redblock Engine
The Volvo B21 is a slanted straight-four engine first used in the Volvo 200 series, meant to replace the B20. The B21 and all derived engines are often referred to as red block engines for the red paint applied to the block. The primary differences when compared to the B20 was the switch to a SOHC in place of the older pushrod configuration, and an aluminum crossflow cylinder head versus the iron head of the B20. History Initially the overhead camshaft versions were offered as optional equipment on the 240, becoming standard in all markets by the 1976 model year. The overhead camshaft motors were available in displacements of 2.0 (B19 and B200), 2.1 (B21), and eventually 2.3 (B23 and B230) litres. The B21 featured an stroke, and bore. In the US, the B21's power output ranged anywhere between and , based on variations in the compression ratio and was typically supplied with a B or M camshaft. The engines are tilted approximately 15 degrees to right (exhaust side) to make room for the more complicated injection systems. B19 and B21 blocks can be identified by water plugs on one side of the block. The B23 blocks have them on both sides. The camshaft is driven by a toothed belt that is driven off the front of the crankshaft. The belt turns the intermediate shaft as well, which in turn drives the oil pump, distributor (on 240 engines and BXX 700/900 series engines) and the fuel pump of carburetor models. All single camshaft versions of the engine with the exception of the K series (B200K, B230K) are of 'non-interference' design, meaning that failure of the toothed belt will not result in engine damage. In 1981 the B21FT (a B21F with a turbo) was introduced with a compression ratio of 7.5:1 mated with a Garrett T3 turbocharger and a T camshaft. Additional turbo variants, not offered in the US market, were the B19ET and the B21ET, based on the B19E and B21E respectively. The turbocharger increased power output to for the B21FT, and for the B21ET. boost on the B21FT and boost on the B21ET. Also new for the 1981 model year in Canada (previously introduced in 1979 outside of North America) was the B23, with a displacement of 2.3 litres ( stroke and bore). Aside from the increased bore size, the engine is identical to the B21. Volvo used a slightly different mold for the turbo engines to cast a boss for the turbo oil return line. Because a turbocharged engine has a higher operating temperature they used sodium filled exhaust valves and a thermostat controlled oil cooler (air/oil model). In 1983 the B23 was introduced to the United States market as a B23F engine. Also introduced in 1983, the "intercooler boost system" (IBS) was introduced for the B21FT motors. The IBS kit consisted of an intercooler, appropriate ducting, a new fan shroud, new oil cooler lines and mounting brackets, and optionally an automatic transmission kit. IBS raised the output