About the Cummins engine ISX15 and Cummins QSX15

• Cummins ISX15 was introduced in 2019, while theCummins QSX15 debuted in 2021. These two engines differ significantly in their structural design: the QSX15 employs a dual overhead camshaft (DOHC) configuration, whereas the ISX15 utilizes a single overhead camshaft (SOHC) configuration. These distinct designs result in different power outputs and performance characteristics for the two engines.

• To illustrate these differences more clearly, I have provided visual representations of the single-camshaft and dual-camshaft structures below.

CUMMINS QSX15 CYLINDER HEAD

CUMMINS ISX15 CYLINDER HEAD
The first image illustrates a single-overhead-camshaft configuration, while the second depicts a dual-overhead-camshaft configuration. Through these two images, I believe you will be able to more intuitively discern the differences between the QSX15 and the ISX15.
Regarding the Differences Between the Cummins QSX15 and ISX15 Upper Gasket Kits
Due to their distinct structural designs, the Cummins QSX15 and ISX15 engines exhibit differing performance characteristics. Furthermore, there are significant differences in their individual components?such as the cylinder heads, camshafts, and oil pumps. Today, however, our primary focus is on the distinctions between their Upper Gasket Kits.

• CUMMINS QSX15 UPPER GASKET 4955595

CUMMINS QSX15 UPPER GASKET KIT 4955595
CUMMINS ISX15 UPPER GASKET KIT 4955596

cummins ISX15 upper gasket kit
Based on the tables and images presented above, we can observe that the primary differences between the Cummins QSX15 and Cummins ISX15 lie in the exhaust manifold gasket and the thermostat housing cover gasket. Additionally, in terms of component composition, the Cummins ISX15 4955596 is somewhat more complex.
Although they are similar in appearance, the ISX15 and QSX15 are not interchangeable in many respects.