If it's a Johnson, it's the one that has the American flag on the box. I'm not bashing the quality of the component, just sharing the findings. I work in manufacturing and know s#it happens once in a while. One engine was relatively quiet and the other one had a couple noisy lifters. It's just the $1800 in lifters and the labor. It could have been worse if not caught. See above, that sucks endeavor1

How old are the lifters...first I've seen or heard a Johnson failure. Surprised but I'm sure it happens. Good luck!!

They were 2 summers old when replaced last year. (Michigan)
Just took apart this week.

Buy a lottery ticket !!!!

So, educate me please. It is ok to replace a hydraulic roller lifter with a solid roller lifter w/o changing the cam? I thought about doing this but was unclear if it was acceptable. Thanks

I was always under the understanding, that a solid roller camshaft, has lash ramps built into the cam lobes. One cam grinder i spoke to a while back, advised against running solids on a hydraulic cam lobe, as it could be hard on things.

A buddy of mine had some 509s that had that setup, and the valvetrain suffered some parts failures after not alot of hours . I do know some guys run that setup and have good luck.

Quote from Mike Jones of Jones cams.

Assuming the cam has a .006" "hydr" ramp(it could be a .004" ramp), to reliably run mechanical roller lifters on it, you would need the Hot lash to be below .0108"(.006"x1.8 ). With an aluminum block and heads, I would bet you're getting more then .012" growth from cold to hot, so even if you set the cold lash at .0000", you would be off the ramp when the engine was hot. That will put the valve acceleration, on and off the seat, way too high, and shorten the life of your valvetrain.
If your cam is one of Comp's more aggressive cams, with only a .004" ramp, or one of their profiles with no ramp on the opening side, the acceleration would be even higher.

Bottom Line: If you want to run mechanical roller lifters, run a cam that's designed for mechanical roller lifters. If you think you've got a better idea, then the guys that are designing the cams, you don't

That being said. OBVIOUSLY following the rules didnt work out for rookie. Question is, was it a fluke, a lifter issue, or a cam issue.

I know a certain persons cams, had a good track record of breaking all kinds of stuff. Lifters, rockers, valve seats, and so on

Just to clarify this is not my setup and not said certain person's cams. Mild 230/240 something Comp cam low 0.600" lift RV cams lol