Quote:
Originally Posted by Tim Corcoran
Jay, what is your opinion on longevity of running a solid roller lifter on a hyd roller cam on the street. I know the OEM's ran a lot of solid flat tappet cams in the past but the modern roller cams OEM's use hyd rollers and not solids. For the street I would use a solid roller, except I worry about longevity.
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There’s not really a no or yes answer to that. I think it depends on the profile, spring pressures, expansion rates of the heads, and the hot lash.
If a HR set up makes any noise at all, and the hybrid makes none and runs about the same spring pressure with the same cam, the hybrid will out last the full HR set up.
If the HR is dead quiet, it should last just as long.
If the heads have to much expansion rate and the lash gets opened up to much hot, the hybrid probably won’t last near as long as the HR if it is functioning right. That really needs a some type of rev kit if you want it too last on the street, then it would likely out last the HR set up. The SR lifters have bigger diameter rollers, some even have heavier pins and bearings.
There are some mechanical profiles that will out last many of these current aggressive HR profiles that are running lifters that have uneven bleed rates, especially if the cam is one of those that run 51*-52* of intensity. Which is what is commonly sold. I have one of those I run as a hybrid.
I have SFT, HFT, HR’s and full SR mechanical cams in my cars, honestly the hybrids I have are my favorite street cams.
Most heavy duty Diesel engines run mechanical roller lifters. Not everything has went to HR cams, mostly they are used in the gasoline automotive engines.