—”A detailed study of a cylinder activation concept by efficiency loss analysis and 1D simulation”
...In most of the current cylinder deactivation designs, both the air and the fuel supply are switched off for the inactive cylinders. For this purpose, usually the intake and exhaust valves of these cylinders are deactivated, which eliminates the gas exchange losses. In addition, the gas trapped inside the deactivated cylinders acts as a pneumatic spring, resulting in only minor in-cylinder process losses, mainly due to heat transfer to the combustion chamber walls. As there are no gas forces due to combustion in the deactivated cylinders and piston, lateral forces are, therefore, significantly reduced, friction loss is also comparatively low...
https://link.springer.com/article/10.1007/s41104-020-00070-1
Thanks. Yeah,if it is cycling fast enough, it is adding heat/removing heat fast. Might mitigate the overall heat transfer losses.
Still waiting for my buddy the thermo guy to email me back...he’s an absolute expert.