We installed a reman cylinder head, new cam, some new rocker arms and one new injector in a Series 60. The truck is a 98 Kenworth. After repair the owner operator claimed that the engine never ran this good and that he had improved fuel economy along with way more power. At approx 5000 miles after repair an intake valve dropped on #5 destroying the head, piston and liner. We sent the head back to the original machine shop and they are claiming that all the valves are bent. We checked valve lash before disassembly and all valves were right on. I am searching for a possible cause other than over speed.
If all of them are bent I would think there would have been marks on all the pistons?
If the RPM went to the moon that event should be logged in the ECM. Truck Shop
Yup.. TS is correct, depending on what series the 60 is, it could/should have a "brain".. Its alittle late now, but you could have checked the rack to MAKE SURE they didn't tamper w/ the fuel setting. ANY smell of starting fluid?? I use tamperproof hardening sealer paste on ALL fuel & rpm screws.. RED.. so I KNOW if its been touched. It "breaks-off" when the screw has been loosened.. no way to hide that..
Probably only a dealer would have the DDEC Reports program to pull the highest RPM, My SWAG: somehow, timing got a tooth off? Cam gear is Pinned to Cam, so it shouldn't have slipped, Wrong CAM? Wrong (thinner) head gasket? Head shaved down too far? How did you check valve lash? Did you do the whole multi step process of Rolling each cylinder to max injector, (or is it intake) stroke? Did you use the Cam gear retainer to hold it in place when you swapped the cams? or just mark the teeth? Did you reset the gear lash? It would have changed with a new head