Derating an engine

I think it was Watson’s cold stores down at Hemmant had big Cat engines running the ammonia compressors.
They were petrol engines running on LPG. Had a huge spark plug in place of injector and a magneto where the injector pump used to live. Low compression pistons were part of Cat’s petrol conversion.
Very quiet when running, reckon they’d last forever.

We bought a secondhand TR96 New Holland header (harvester) in 1994. Beautiful machine, massive capacity, and pretty much impossible to overload as the engine horsepower was perfectly matched to the capacity of the machine. Never bothered with grain loss monitors, just drove it on rotor revs, and that was predominantly on 48' barley windrows. Few years later traded it on an equivalent size machine, just 2 models newer. Only difference mechanically was the newer machine had a new generation of engine with more power and different torque curve. It proved to be a terribly wasteful machine. It seemed the engine was capable of pulling more crop through the machine than the workings were able to handle. So after making some enquiries with diesel injection specialists, i cut the maximum fuel screw back either a quarter or half a turn (just not sure now), and used it like that all the time we had it. My aim was to cut it back 30 horsepower, and it felt as if i achieved that fairly accurately from the advice given. However the next owner was a "power user" and got me come and put it back to the factory setting for him.

From my wrecking yard days, you could pretty much draw a line from engine power/ engine longetivity (spelling?)
So for the same engine "block" be it 250 Ford, 202 Holden, L20 Nissan, you name it- the small under rated versions of the same thing, IE Holden 138 Red motor, or Ford 200, and so on, were just about bulletproof. We'd just about have to scrap a 200 Ford, as you's simply never sell it. Mazda, Mitsubishi, same same.
And it seemed the same all the way across the engine makes- smaller output with the same block as an engine with a higher output, was a far better engine.
I wonder was it the same with truck engines? For example, I have never heard a bad word about say a Cummins NTC 230, they were the same 14 ltr block as a 400 I think? Were they a longer lasting engine?
And a 12.7 Detroit was a much better engine that a 14 ltr, or so I am told..
I guess maybe power has it's price eh?

I can remember a sign from Merc Waggots speed shop from my misspent youth. “Speed costs money, how fast do you want to go?”

Plus their Blue EH van had "Atomic Power" on the side.