Engine Masters episode 16, presented by Amsoil, will roll you flat with knowledge on roller vs. flat-tappet cams and lifters. At first glance, one might think that the reduced friction of the roller is the secret sauce behind the horsepower improvement over a flat-tappet valvetrain — but that’s not the whole story! Using our formally tunnel-ram equipped BluePrint Engines 400ci small-block Chevy, David Freiburger, Steve Dulcich, and Steve Brulé test two Iskenderian cams to show you the different capabilities between the different lifter types, and you can be the judge if that extra horsepower is worth your extra dollars.
With a sizable price difference between flat-tappet and roller cams, the traditional “How fast do you want to go?” budget is the all-mighty voice in your selection of speed parts. Engine Masters will show you why the reduced contact patch of the roller lifter allows for a more aggressive camshaft profile, demonstrating how a faster ramp rate that allows for more lift per total degree of duration. The short-story is that the valve is able to open quicker and stay open longer for the same cam duration, producing more horsepower over a wider RPM range than a similar flat-tappet cam. Additionally, you buy yourself some reliability, as a roller lifters are less likely to wipe a cam lobe. Anyone who’s broken-in more than a few flat-tappets cams can attest to how temperamental the lifters can be, though that potential reliability comes at the expense of more parts to retrofit earlier Chevy blocks.
If you want to dig into more camshaft science, read Steven Rupp’s Roller vs. Flat Tappet Cams: Which is Better for Your Chevy