ACERT engines are notorious for compromising spacer plates, failing turbo's and breaking exhaust manifold studs. In fact, Caterpillar offered a special tool-jig with high rockwell drills especially for drilling out and replacing broken exhaust studs. The number 2 service related issue in the Western Star dealership / shop I retired from was repairing ACERT engines, mainly spacer plates and exhaust studs and I drilled out many exhaust studs in my tenure there.
Keep in mind that when Caterpillar divoriced itself from the on road engine market, they have, since then, also divoriced themselves from the replacement parts business as well so today, replacement-upgrade parts are NLA from Caterpillar and replacement-upgrade parts come from mostly offshore manufacturers.
Candidly, I was never impressed with the torque rise of an ACERT engine in the first place and I got to motor them regularly when not in the shop getting dirty. I much preferred the 3406 Alphabet engines over it.
Horsepower means little in a diesel engine. People like to dwell on horsepower but in reality it's the torque rise that provides the work done when loaded. Horsepower means little.
In this country today and yesterday, people always seem to equate horsepower with performance when it's torque rise that makes productive work easier.
My 3406 B model that is presently sleeping in the barn is set at 475 horses but the advertised torque rating is 1750 pounds feet and it has no emission junk on it, never did actually.
475 horses was the maximum allowable by Caterpillar to keep in force the extended warranty that all the fleet trucks ran. Sure, you could shim the pump for more, way more actually, but above 475, Cat would deny any extended warranty claims.
Keep in mind that the more torque delivered, the higher the driveline issues became as well as drive tire wear.
The tractor I own has a 15 speed Eaton Roadranger in it and when the trailer is loaded (or should I say overloaded, which is the norm for a hopper bottom grain trailer, if you get on the loud pedal on the low side of the tranny, you can literally feel tire squirm and squirming tires equal accelerated wear and why I refrain from hard acceleration when taking off loaded. Tires today, especially today, aren't a cheap date and becaus the unit I own is more for a hobby deal, I'm always aware of inherent operating costs. Someday, I'll post up a picture of it. Not photogenic at all actually. Classic, long nose Western Star double bunk and a 42 foot Timpte hopper bottom tandem frameless grain trailer. Old school drum brakes and pennies in the front brake hoses to insure the front axle brakes are inoperable. Not a fan of steer axle brakes on any semi truck.
