This B18 is a automobileInline-four engine produced by Volvo from 1961 through 1968. The cam-in-block engine had overhead valves operated by pushrods. The crankshaft rode in five main bearings, making the B18 quite different in design from its predecessor, the three-bearing B16. A larger version called the B20 appeared in 1969. These engines are reputed to be very durable. The world's highest mileage car, a 1966 Volvo P1800, traveled more than on its original B18 engine. Despite their OHV and pushrod design, the engines can rev to 6,500 rpm.
B18A: 8.5:1-8.7:1 compression. single carburetor version. SAE
B18B: 9.5:1-10:1 compression. Dual carburetor version. SAE with a higher compression ratio, fitted variously with dual sidedraft SU or Zenith/Stromberg carburettors.
B18C: single carburetor version. SAE with a lower compression ratio and 2500 RPM mechanical regulator, fitted in the gasoline powered versions of the Volvo BM320tractor. This version was also used for the elevator in the PS-15 radar system.
B18D: 8.5:1-8.7:1 compression. Dual SU carburetor version. SAE
In 1971 Swedish engineer Gunnar Axelsson developed a DOHC cylinder head for the B18 engine family. This cylinder head was used in competition Volvos for several years. On 1 January 2014 the Grainger & Worrall company announced that they had partnered with Axelsson to reproduce the DOHC head for the B18 engine. Power output of the base engine was expected to be, while a high-output version developing would also be available.
B36
In 1952 Volvo unveiled the Volvo Philipconcept car powered by a 3.6 litre V8 engine that would later be called the B36. The V8 engine had exactly the same bore and stroke dimensions as the four-cylinder B18, leading some to suggest that the B18 is one-half of the V8. Significant differences between the two engines included the fact that while the cylinder heads on the V8 are crossflows, the four cylinder has both intake and exhaust ports on the same side. This suggests that the engines are for the most part separate designs.
B20
The B20 engine displaced, with the cylinders on split bore centers, where the spacing between cylinders 2 and 3 is wider than between cylinders 1 and 2 or 3 and 4. The design is virtually identical to the earlier B18, but with an enlarged bore, 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 BoforsHaubits FH77howitzer. 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: 8.7:1 compression. Single carburetor version.. First produced in 1969.
B20B: 9.5:1 compression. Dual carburetor version. with a higher compression ratio, fitted variously with dual SU or Zenith/Stromberg sidedraft carburetors. First produced in 1969.
B20D: 8.7:1 compression. Dual carburetor version. up to 1971 then from 1972 with a lower compression ratio, fitted variously with dual SU or Zenith/Stromberg sidedraft carburetors. First produced in 1969.
B20F: 8.7:1 compression. D-Jetronic fuel injection up to 1973 then K-Jetronic fuel injection from 1974 on.. 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. From 1975 the thread standard changed from SAE to Metric as Volvo switched over with the new 200 series. The B20A was revived for four years 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.
