Testing the 273 on the dyno....
My memory is that net hp was first widely used in 72.
However, in 1955, Chevrolet posted both gross and net figures for its new small block 265 inch V8 (gross and net figures are both at the crank, not at the wheels, but gross used cold intake air, cold carburetor via blocked heat riser, no fan or other accessories, dyno exhaust, etc, while net was hp at the crank in production trim with production timing, carb heat, intake air heated to typical underhood temperatures, all accessories including fan, water pump and generator hooked up, etc.).
The two barrel motor was rated 162 gross, 137 net. The power pack motor (4-barrel carb and dual exhaust) had 180 gross, 160 net. These figures are from the January 1955 Issue of Hot Rod Magazine, article entitled "Analyzing the Chevrolet V8" by Racer Brown, tech editor (yes the same Racer Brown of camshaft fame).
My memory is that net hp was first widely used in 72.
However, in 1955, Chevrolet posted both gross and net figures for its new small block 265 inch V8 (gross and net figures are both at the crank, not at the wheels, but gross used cold intake air, cold carburetor via blocked heat riser, no fan or other accessories, dyno exhaust, etc, while net was hp at the crank in production trim with production timing, carb heat, intake air heated to typical underhood temperatures, all accessories including fan, water pump and generator hooked up, etc.).
The two barrel motor was rated 162 gross, 137 net. The power pack motor (4-barrel carb and dual exhaust) had 180 gross, 160 net. These figures are from the January 1955 Issue of Hot Rod Magazine, article entitled "Analyzing the Chevrolet V8" by Racer Brown, tech editor (yes the same Racer Brown of camshaft fame).