M11 verses ISM and the actual differences

July 08, 2012, 01:24:45 pm

Could somebody explain the differences between the M11 and the ISM. I did a google search and it seems as though they are similar with more electronic control on the ISM and one comment seemed to show the ISM may be as much as 800 pounds heavier than the M11?

Re: M11 verses ISM and the actual differences

Reply #1 – July 08, 2012, 02:14:56 pm

Hope this sheds a little light on the situation. I am sure there are others that will be able to explain a lot more.

History of the L10, M11 and ISM:

The Cummins M Series engine is a straight six diesel engine designed and produced by Cummins.
It displaces 10.8 litres (659.1 cu in). Introduced as the M11 in 1994, it was built on the previous L10 engine (same 4.921 inches 125.0 mm) cylinder bore, but a longer 5.787 inches (147.0 mm) piston stroke compared to the L10's 5.354 inches (136.0 mm) stroke).
In 1996, Cummins added electronic controls to improve efficiency. This model became known as the M11 Plus.
The M11 Plus became the ISM when Cummins applied its Interact System (hence the "IS" in ISM) to the M11 Plus to further improve the engine. The ISM is available in four different configurations, with slightly different emphasis on maximum power (450 horsepower (336 kW; 456 PS) vs. 500 horsepower (373 kW; 507 PS)) and peak torque.

Years of Production and available Horse Power

L10 = 1983 to 1991 (240 to 320 hp)
L10 CELECT = 1992 to 1998 (280 to 350 hp)
M11 CELECT = 1994 to 1995 (280 to 350 hp)
M11 CELECT Plus = 1996 to 1998 (280 to 450 hp)
ISM (non-EGR) = 1999 to 2003 (280 to 450 hp)
ISM (EGR) = 2004 to 2010 (280 to 500 hp)

Cummins is planning to phase out the ISM for 2011 in favor of the 11.9-liter version of their ISX series.
The Cummins ISM is the alternative engine to the larger ISX for local and long haul applications. Although mostly seen in daycab tractors and vocational trucks, the ISM engine can also be found in large motorhomes and fire equipment. Designed as a replacment for the original M11 engine, the Cummins ISM began with the CM570 fuel system and progressed with the following:

1.) In 2002, upgraded to the CM875 fuel system which included an EGR valve for EPA emmission compliance.
2.) In 2007, upgraded to the CM876 fuel system. This fuel system still includes the EGR, but also added a Diesel Particulate Filter (DPF) to conform to the new EPA standards.

Re: M11 verses ISM and the actual differences

Reply #2 – July 09, 2012, 07:57:14 am

Thanks Jerrett, Do you know if there is a weight difference ? Great Post!

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