What gives CAT engines their distinctive "whine" noise?

While many diesel engines have it to some extent, I can usually tell a CAT engine apart by their distinctive "whine" that is more heavily pronounced. It's almost like background noise if you will that fluctuates with the RPM. Is it the particular way the teeth are grooved in the timing gears?

Just to clear the air, no, I'm not referring to turbo whistle, the exhaust, or some issue that's wrong with the engine. If you've been around many diesel engines in your life which most here have and also retain an acute ability to differentiate engines based purely on sound alone, the slight whine that many CAT engines make is a dead giveaway.

And by the way, I think it's a great noise that only adds to the fierce growl they're known for.

 

The only whine I’ve ever heard in regards to a Cat engine, is the whine of the Owner at the repair Shop when he gets the bill. Sorry I had to say it. Lol. I think it’s just the higher torque that gives it a staying power that’s lost on Detroit’s or Cummins. I know that sound, heard it many times as a friend of mine winds up his 550 and walks away from my Truck ( while he’s grinning from ear to ear). That’s when I ask him “ how much was that turbo you put on?” $3000 vs $700 for my Detroit. Lol

 

That $3000 is what you’re hearing

You’re not going to hear a whine from a $700 turbo. It’ll blow up first lol

 

Driving on I 40 on my way to California on the Oklahoma/ Texas section, I encountered a Trucker that was pulling a Van, while I was pretending to be a trucker in my wife's Ford explorer. I like to drive at night on long road trips and on this occasion Mr Peterbilt and I were on the road together between 2300 and 0100. Since I like to drive at night I often find myself surrounded by big rigs rolling down the interstate. I often feel sorry for the Truckers because usually it takes so long for one big rig to pass another, however a week ago I was following Mr Peterbilt for 2 hours and he was passing trucks with ease and doing it T 80 MPH.

Now that I have everyone bored from me rambling on, my question is: what kind of engine was in that Pete that could keep him rolling at 80 MPH steady? Can all trucks do 80 if they are not governed?

 

At 80, my contract gets cancelled. But yes, ungoverned trucks can get down the road with ease. Tire ratings are what keeps most drivers from running faster than 80.

Hard to say what kind of engine he had. But most can run for days on end at that speed. If they had enough fuel

 

Probably a Cat, most Pete’s have Cats. Newer ones I imagine have Paccar engines.But any real Driver worthy of being called Mr Peterbilt , would have nothing less than a 550 Cat and at least 13 but probably 18 gears. And a big ol belt buckle and cowboy boots. And a big wallet full of money

 

Peterbilt,cat,18spd.. check. Just a regular ol beltbuckle and work boots. The wallet is full of plastic, 99% of which is rewards cards.

 

that big wallet has to be chain-driven...