A = water Aftercooled engine
as in 4BTA3.9
But AA = Air Aftercooled engine, or charge air cooling
as in 4BTAA3.9
and NA = Naturally Aspirated
B = B series engines
includes 3.3, 3.9, 4.5 and 5.9 liter engines.
both fully mechanical and electronic models.
industrial and automotive versions.
C = C series engines Only 8.3 liter engines. both fully mechanical and electronic models. industrial and automotive versions.
E = electronic engines. Older engine model designation meaning the engine is electronic. e.g. K2000E
I/IS = Automotive engines that are electronically controlled.
IS = Interact System (e.g. ISX, ISB, ISL) Interact System meaning that the engine is capable of interacting with the transmission and other electronically controlled devices in the truck or bus.
K = K series engines Includes 19, 23, 38, 45, 50 and 60 liter engine models.
L = L series engines Includes older 10 liter and current 9 liter engine models. industrial and automotive versions.
M = M series 11 liter engines Industrial and automotive versions.
N = N series engines Includes N855 and N14 engines. Still Available from Cummins China and other countries but no longer produced for U.S., Japanese and Euro markets.
Q/QS = QUANTUM SYSTEM CONTROLS
Industrial engines that are electronically controlled.
T = T series engines The T in electronic engine names is part of the actual engine model e.g. the QST30.
However in mechanically controlled engines
The T = Turbo e.g. 6BT
X = X series engines Only 15 liter engines.
Industrial and automotive versions available.
6CTA = 6 cylinder, 8.3 liter, turbocharged, aftercooled engine
ISM11 = automotive, electronic interact system, 11 liter engine
ISX15 = automotive, electronic interact system, 15 liter engine
QSX15 = industrial, electronic, 15 liter engine
If a number comes first in the engine name it indicates the number of cylinders. e.g. 6BT = 6 cylinders, 4BT = 4 cylinders.
If a number comes last in the engine name e.g. the 3.9 in the model 4BTA3.9 the 3.9 = the displacement in liters