Costanza - 12/21/2024 21:05




ISX is certainly not a 600,000 mile engine. They will last well over 1 million miles if driven right. I have 2, 1 has 1.2 million and the other has 1.3. They've not had anything other than overheads done on them. They will pull with anything but you can't drive them like a Cat. If you're going to lug them all day at 1400 rpm's, you're asking for trouble. They have short connecting rods and they don't like that. 1600 rpm's is their sweet spot, if the truck is geared to where you can run there, they will last as long as anything. The biggest problem with that engine is a lot of freight/fleet trucks have that engine in them. And what do they do? They gear them so they run 1200-1300 rpm's running down the interstate so they get good fuel mileage. They get good fuel mileage but that is killing they engine. They don't care cause they trade at 300,000 miles. Then the second owner buys it and is told the truck has never been abused because all it's done is cruise up and down the highway. When in fact, the damage has already been done. As far as counter-bores go, that's irrelevant. They all need counter-bores cut. I won't overhaul a big bore engine without cutting them, it's not that big a deal. But, as it's been said, you're going to get all kinds of contradicting information on this topic here.