Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Normal
In documentation I have from the 50s produced by GM for fleet truck buyers, there are pages for each engine showing curves for net and gross hp and torque. These are listed as "certified" and signed off by an engineer. Is one to believe the engineers had put their credibility on the line by signing off on these charts? Would fleet buyers call them on it if performance did not prove out. I don't know but a later set of dyno runs by McGurk written up in a 1955 Hot Rod Magazine article showed much lower figures than the certified GM pages.A 261 C.I. inline six rated at 145 only produced 114 crankshaft Hp on McGurk's engine dyno. What the real world figures were is a bit of a mystery as they were looking for improvement with various modifications and were able to considerably beat the factory figures with a still streetable engine, 165 vs 145. Given the tractor-like basic design and limited head potential that'a about all one could expect.
In documentation I have from the 50s produced by GM for fleet truck buyers, there are pages for each engine showing curves for net and gross hp and torque. These are listed as "certified" and signed off by an engineer. Is one to believe the engineers had put their credibility on the line by signing off on these charts? Would fleet buyers call them on it if performance did not prove out. I don't know but a later set of dyno runs by McGurk written up in a 1955 Hot Rod Magazine article showed much lower figures than the certified GM pages.
A 261 C.I. inline six rated at 145 only produced 114 crankshaft Hp on McGurk's engine dyno. What the real world figures were is a bit of a mystery as they were looking for improvement with various modifications and were able to considerably beat the factory figures with a still streetable engine, 165 vs 145. Given the tractor-like basic design and limited head potential that'a about all one could expect.
