Tag: oil

In spite of the wholesale O.E. switch to roller lifters that started a couple of decades ago, if you’ve got a vintage rod chances are it has flat tappets, and maybe you don’t want to go to the trouble and expense to retrofit to rollers. Plus, some racing venues only allow flat tappets. These operate at higher temperature and pressure levels at the lobe/lifter interface than rollers do, so require greater wear protection. The primary anti-wear additive for flat tappet camshafts and lifters is ZDDP (zinc dialkyl dithiophosphate), but that’s been phased out of ordinary motor oils mostly because of fears that it’ll foul the cat. Racing oil and additives provide zinc in adequate quantity to provide the protection you need to prevent catastrophic lobe and lifter wear.