suggests that the engines are for the most part separate designs. B20 With the same stroke as the B18 but a bore enlarged to , the B20 displaces . The cylinders are on split bore centers, where the spacing between cylinders 2 and 3 is wider than that between cylinders 1 and 2 or 3 and 4. The design is virtually identical to the earlier B18, thus most parts are functionally interchangeable, albeit with running changes to the manufacture and design of components. The B20 engine was used in the Volvo 120, 1800, 140, C202 and 240 series, and also in the Bofors Haubits FH77 howitzer. A modified version was used in the one-off 1969 Volvo GTZ concept car. The B20 was produced from 1969 to 1981. There are five variations of this engine: B20A: Single carburettor version. First produced in 1969. B20B: Dual carburettor version with a higher compression ratio. First produced in 1969. B20D: Dual carburettor version with a lower compression ratio. First produced in 1971. B20E: Fuel injection version with a high compression ratio. First produced in 1970. B20F: Fuel injection version with low compression ratio. First produced in 1972 for lower emissions. The B20E and B20F versions featured larger valves, and intake/exhaust ports and for 1974–1975 switched from electronic D-Jetronic to mechanical K-Jetronic injection. In 1974 the number of bolts holding the flywheel increased from 6 to 8 and the size of the connecting rods was increased. The B20A was revived for use in the C202 from 1977 to 1981. B30 From the 1969 model year Volvo produced a six-cylinder version of this engine called the B30 for the newly released Volvo 164. Adding two extra cylinders with the same dimensions to the B20 produced a engine. Engine chart See also List of Volvo engines Volvo B30 engine Volvo PV544 Volvo P210 Duett Volvo 120 (Amazon) Volvo P1800 Volvo 140 Volvo 240 Volvo C202 References External links B18 Gasoline engines by model Straight-four engines