Cummins ntc 335

Parasitic loss may have been the wrong way of putting it. A roots type blower takes horsepower to turn, even if it's not overdrive like dragsters. Are you sure that belt drives are not more efficient than gear drive? I had learned they are.

The info regarding early mufflers is interesting. My dad used to call the turbo on a 262 a smoke turbo. I guess it would have been more correct to call it a fire turbo.

 

The first superchargers Cummins ran in the 40’s were belt driven. Sometime in the ‘49-‘50 time frame they changed to gear drive. They said to make them more dependable and maintenance free. No mention of parasitic loss reasons. The hp rating stayed the same for awhile then was uprated to a 275 on the NH.
The NHC250-855 with a turbo became a “280” but it was just a smoke kit like the NH220-743 which became a “262”