Just a random thought, not connected to anything: What's the difference in a B3.9 and a 4B, and which one is identical to a Case 4-390?
Only thing I know for sure is the Case/Consolidated diesel 390 has a different front housing than the Cummins engines, tried to do a quick front cover reseal on a Cummins 4B with a Case gasket. Oops, no Bueno. Also it seems the injector pump options are endless for both.
Are a 4B and a B3.9 the same? I thought a B3.9 and a Case were the same.
Ok, so this has come up in another thread just below. In my opinion the B3.9 and the 4bt (3.9l)is the same engine. As stated above there can be various front covers related to injection pump type. The 4-390 is the same as 4bt. Just as the 6b(5.9L) is the as the Case 6b-590. But I am curious to find out about this B3.9 engine and if it is different. There could also be various block configurations older blocks had pipe threads for oil galley ports where as the newer block have oring boss ports. So I think they are all the same engine family just with updates along the way. This page from a Cummins publication shows the same engine refrred to a B3.9 and a 4b