DD 8V71T specs. What components went into turning 435 hp to 462 hp in later years?

I recall reading here (can't remember who posted it) that companies that use diesels in truck and heavy equipment do their maintenance by hours of run time and by gallons of fuel consumed- because inorder to make power, you burn fuel, and to make more power, basically you burn more fuel. That also takes more air, and cooling of the intake charge air, and in turn getting rid of all the waste heat that isn't turned into power.... but it seems like essentially to make more horsepower, you have to burn more fuel. Is that true? At least it makes sense to me.

For the most part, yes. However, power is related to work. What actually gets produced more is energy. How much of that gets converted to work (power) depends on other factors. But within certain limits, the more fuel (and air) you can burn, the more power. Fuel is generally not the issue, it is getting enough air (oxygen) that is the task.

This comment is not exactly about this thread , but Cap Ralph mentioned switching blower speeds. This was recommended to me by RPM Diesel . They said no downside, just more air and less smoke. Has anyone done this ? I didn’t really think that I needed this , so I didn’t pursue the issue.

Intersting..... how does one do that? New vane wheel with different vanes on it? Or completely different turbo? Do the standard ones have waste gates on them and are producing more than you need anyways?

He means the Roots blower, not the turbocharger. It's a drive gear change.

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Originally Posted by Avenger

He means the Roots blower, not the turbocharger. It's a drive gear change.

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Ah, that makes sense. Thanks.

BTW, there's no free lunch. Increasing blower speed costs horsepower. Anybody tells you there's no downside needs to consult with an engineer.

Quote:

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Originally Posted by Avenger

BTW, there's no free lunch. Increasing blower speed costs horsepower. Anybody tells you there's no downside needs to consult with an engineer.

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Correct.
Now, if there is a turbo in front of the blower, all bets are off. It is the correct combination of these that work in harmony with another factor, the injector.
Also, don't forget cold air...

All components must work together to ensure the correct fuel / air mix.
There is no back yard Frankensteining here.
It's by the DDC book and usually not shared.

I have my notes that will be buried with me. When I come back riding my DD trike with flames coming out my hair, I may need it..

There are not many sweet mechanical songs in this world, A properly tuned DD is on the top of my list, Then maybe the Philly Harmonic.. Maybe a 12V71TI screaming on playback when I'm planted.

How does one change blower speeds when the center to center dimensions / diameters of the camshaft drive gears, the blower drive gear and the blower drive quill shaft center are fixed?


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If anyone's interested, there is a really handsome ALF pumper on BaT right now, featuring an 8v71 DD, a natural, well-restored and just aching for a new home. Former property of the Concord, NC FD. Beautiful old truck.