Cummins Big Cam History
Interesting facts and data about Cummins Big Cam engines.
Big Cam I
The first Big Cam I engines were introduced in 1976.
Cummins aimed to meet new US government legislation at that time
regarding noise levels and clean air requirements.
This engine replaced the Small Cam 855 series engines and it features
a greater camshaft diameter and the introduction of top-stop injectors.
Visual differences
The major visual difference between small and big cam engines
is that the cam boxes on the side of the engine were made much larger in big cam
engines.
This feature made the big cam engines instantly distinguishable from
small cam engines.
Refer to the preceding photos
Known Big Cam I CPL numbers
205 222 266 287 294 298 306 308 310 327 322 323 324 327 328 332 344 353 354 369 393 463 499 537 582 661
Cummins Big Cam II
Big Cam II
Big Cam II engines were introduced in 1979.
The new features in this engine were:
- demand-flow cooling
i.e. only cool when the engine demands it
to use the saved horsepower for output work - pulse exhaust manifold introduced
A big increase in performance
Some users upgraded their big cam I engines
with pulse manifolds just to get this increased performance. - T46 turbo chargers introduced

Big cam II still using the aluminum oil pan

Pulse Manifold introduced with Big Cam II
Known Big Cam II CPL numbers
329 330 338 339 345 349 377 391 392 414
433 449 450 454 455 456 457 458 459 473
481 482 483 485 491 492 506 509 516 518
529 536 543
Cummins Big Cam III
Big Cam III
Big Cam III engines were introduced in 1983.
The new features in this engine were:
- New pressed steel oil pans
- a very noticeable feature - New oil cooler and water pump
- Top Stop injectors modified to DFF
DFF - (Direct Fuel Feed),
extra fuel flow assists cooling - Holset HT3B turbocharger introduced
Known Big Cam III CPL numbers
530 531 553 554 558 578 579 581 585 586
588 606 611 612 614 615 616 617 625 632
634 635 650 653 654 657 677 702 743 744
757 789 891 988 989 1310 1411
Cummins Big Cam IV
Big Cam IV
Big Cam IV engines were introduced in 1985.
The new features in this engine were:
- New intercooler introduced
- Cross flow engines introduced
- Cylinder heads modified
not interchangeable with earlier models - Electronic Injection Begun
- Pulse manifolds improved
Some Big Cam IV's are not Cross flow
However, it appears not all Big Cam IV engines had all the new features.
Some new engines coming out of China - are called Big Cam IV but are not cross flow engines - they look more like Big Cam III engines with the Big Cam III intercooler. They do however have new-type pulse manifolds.
Known Big Cam IV CPL numbers
642 658 673 674 675 676 718 749 794 795
796 797 806 811 812 814 821 827 832 833
838 840 903 904 905 910 911 974 1185
1186 1187 1188 1210 1211 1352