How tight to set solid lifters

toolmanmike said

Think about it this way, If the valvetrain wouldn't expand with heat, there would be no reason for valve to rocker clearance. The way you are thinking, you could set them at zero and have no issues. The lash (clearance) is to make up for expansion at operating temperatures.

Click to expand...

I get that. But, you can’t set the valves with zero lash cold because the valves will grow faster than the heads and block. Then the valves will be open and you won’t have compression.

And ambient temperature matters. Check lash at say, 30 degrees and check it again at 100 and see what you get. That’s why there has to be some lash to compensate for cold starts.

When I put my engine on the dyno I will make a video of lash changes. I would hope that would put this to bed, but it won’t.

Thats why running solid rollers on a hydraulic roller lobe is touchy. If you set them at say .004 cold on an 80 degree day and then try to start the engine on a 30 degree day you’ll likely have at least one cylinder that won’t hit because the valves are open.