Hello
I have a 2003 4.0, just completed a rebuild On the engine top and bottom, added a stage one performance cam from Clegg Engines included springs, rods, hydraulic lifters, cam, timing chain and gears, completed the heat soak and test drove the vehicle, took it nice and easy to accommodate the break in period. For an hour and a half it ran beautifully. The next day started it up took it for a drive it started misfiring and banging, a couple of lifters collapsed, I’m familiar with that particular sound, because this is the third set of lifters and rods I’ve gone through on this vehicle the first set were the original OEM with 150k on them, tried a quick fix of just replacing lifters and rods the second set Went the same way as the first and third. Does anyone know why the lifters are collapsing after a few hours of running. All internals were set at torque spec, analyzed and treated carefully. Trashing my engine with new parts and all the work put into it is demoralizing and I’m at a loss, if anyone has some pointers it would be appreciated. Thanks