It’s also what makes a roller valvetrain the best choice for a hot rodded street engine.” But it’s gonna cost ya… This reliability is why the OEMs shifted from flat tappet to roller cams in production vehicles. Also, with flat tappet cams, dialing in the right spring pressure is far more critical compared to the more forgiving roller design. The roller design is far less likely to fail compared to a flat tappet since they are not as reliant on oil splash to keep things functioning properly. … The more aggressive ramp rate of roller cams typically requires higher spring loads to control the valvetrain motion.Īnother major benefit to the roller cam is increased durability. This increased velocity-as much as 30 percent-equates to more power. But don’t take our word for it…įrom SuperChevy: “ The big advantage roller cams have over their flat-tappet cousins isn’t the reduced friction most people immediately think of, it’s increased tappet velocity (i.e., faster ramp rates).
This is because of the rollers on the bottom of the lifter-the smooth rolling surface makes it possible for the more aggressive lobe grinds to be used, as they won’t scrape or bind like the surface of a flat tappet lifter will.
The cam can open and shut the valves much faster, which means they can keep the valve at full lift longer as well. Additionally, lobe profiles can be much more aggressive. One reason is that roller lifters have less friction on the camshaft, which makes it easier for the cam to spin. That being said, roller lifters will offer major power advantages, along with a smoother operating engine. This is enforced to keep things fair in competition-so to compete, you’ll need to abide.
Something like Pure Stock classes will not allow a roller cam or really any cam that’s not within range of the factory-specs cam for the engine you are running. In the case that you plan to drag race, the class you are competing in may not allow you to run a roller camshaft. Why not? Well, because budgets can be tight, rules can be restrictive, and, of course, there are purists and traditionalists. With that in mind, are they the choice for every engine builder? No. (So long as budget and event rules aren’t of concern.) Out of the gate, I will say that roller cams and lifters are pretty much the best all-around choice. I’m not going to pull any smoke and mirrors nor pretend like this isn’t a topic that’s visited regularly. But what’s best for you and why? Flat Tappet vs Roller Whether it’s to go solid flat tappet-based on nostalgia-or to go hydraulic-based on street ability-or maybe even to blow your money on a fancy roller set. However, these little buggers can have a serious impact on performance.Īs you go through your engine build you will have many voices screaming in your ear. They perform a very simple job, which is to work between the pushrods and camshaft to help open the valves. They’re something we can all easily understand. Let’s cut right to the chase: We like lifters.