Engine oils, roller cams, flat tappet cams.
Have you heard of a flat tappet cam flattening lobes lately? Why do we seem to be hearing about this more and more?
Here's part of what has happened; The S rated automotive engine oils have gone through a severe reduction in the zinc and phosphorus levels needed for flat tappet cams. The reason for the reduction is zinc and phosphorus poisoned catalytic converters, and the change from flat tappet cams to hydraulic roller cams rendered the anti scuff properties of high levels of zinc and phosphorus unessessary. Simply put, hydraulic roller cams do not need the zinc and phosphorus flat tappet cams needed.
So what is a flat tappet cam gear head to do?
Well there are a number of options.
With the increase in popularity of the drop in hydraulic roller lifter kits it is interesting to consider the price difference between using Schubeck type lifters on a flat tappet cam vs using a roller lifter cam and lifter combo.
The Schubeck type flat tappet option eliminates any potential problems with the troublesome link bars used in the drop in hydraulic roller conversions. I have had link bars come undone on the dyno, the lifter turns and ruins the camshaft - and your day. The Schubeck flat tappet option is the most solid solution to the flat lobe problem and also offers an option to overcome the potential problems with link bar type hydraulic and solid roller lifters (KISS principle). Using Schubeck mushroom solid lifters can get one very close to solid roller performance with no exposure to the potential failure modes of solid roller lifters.
Food for thought. If you have any questions please e-mail me the current address is on the RevSearch Home Page.
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