Originally Posted by Alan Roehrich
The Comp high end hydraulic lifter is okay if you're on a budget. Nitriding the cam helps, it's well worth the investment, especially on a cast core. Trend is supposed to be working on a short travel tool steel hydraulic. Performance Research Inc had one in the works as well. The tool steel lifters are not as expensive as the Smith's.
DO NOT use DLC coated lifters on a cast core camshaft. EVER.
Yes, you need to remove your inner spring for break in. Your open pressure needs to be below 300 for break in, 250 or so is better. A good 50W mineral based oil, with GM EOS additive, and careful break in is a necessity. I use a premium moly paste on the cam and lifters, and as an assembly oil, I use a mixture of Brad Penn 50W, with GM EOS, and the Comp red lube, if you need to to really stick for a while, during storage, you can mix in STP, but you have to really mix the stuff real well, or it does not work. That stuff really sticks to bearings, cams, and lifters. Just do not ever put it on rings, cylinder walls, or piston skirts.
If you are going to run high spring pressures without using the Smith's (Shubeck) style lifter, then you need to keep your idling time to a bare minimum, and keep your idle above 1200 RPM. You're not going to be able to run the real thin modern race oils either, you'll need to be running the 10W/40 at least, if not 20W/50, the thin stuff simply does not generate the hydrodynamic oil film the budget lifters require to survive. At that point, grooving the lifter bores to feed oil directly to the cam and the edge of the lifter is probably necessary.
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