Designed in the early 1980's the B Series was the brainchild the talented Britsh engineer Phillip E Jones. He was recognised as a rising star at Perkins in the 70's however his ideas proved too radical for the British/Canadian engine builder.
When Cummins hired Jones away from Perkins he demanded a free hand to exercise his many ideas based upon his 'No part is more reliable than any other part philosophy . Starting with a clean sheet, what was eventually to become the B Series was built in a 4- and 6-cylinder configuration. A culture shock for the Americans was Jones' insistance that the motor should be built to metric standards . The engine is known for displacing 1/litre per cylinder with a bore and stroke of 102 x 120mm giving a 4 cylinder 3.9 litres and the 6 cylinder 5.9. The 4 and 6 cylinder engines were basically identical except for the number of cylinders. The internal components, bore and stroke were the same on the 3.9L and 5.9L engine. They also had common valve train components. Cummins designed the B series to be turbo charged from the outset. As a result of Jones design leadership and emphasis on simplicity the new engines had up to 40% fewer parts than the existing 1 litre per cylinder engines from Ford and Perkins. It was also lighter with significantly greater bearing area for ultimate durability.
Summary of changes to the B series
The B series was originally designed as a two valve per cylinder engine. Bosch and CAV pumps were used early on before the Bosch systems became the standard. Significant changes were made to the engine in 1991 in order to accomodate higher power outputs now being demanded. The basic engine design stayed the same with the following revisions:
The move toward lower vehicle emissions in Europe and the U.S resulted in changes to piston design, cylinder head swirl and the uprated Bosch VE rotary fuel pump with the KSB cold start device.
It is the later Euro I and Euro II versions that prove ideal and form the basis of the marine conversions.