Can roller rocker arms actually help add horsepower? The mechanically savvy will likely consider that question and say: “If you have more lift, and open the valves more, then you’ll make more power. That’s obvious.” And they’d be right, because getting more air into the engine does indeed equate to making more power – provided your fuel system can deliver enough gasoline.
But there’s something else to consider: frictional losses between all the myriad moving parts in your engine. Stock rockers, in which metal slides against metal, create a lot of friction. Reducing friction by using needle bearings, some say, helps make the rockers easier to actuate, which means they sap less power from the engine.
But is it true? This episode of Engine Masters attempts to answer that question by comparing stock-type stamped-steel rockers, roller-tip rockers, full rollers, and full rollers with a higher ratio (1.6:1 vs. 1.5:1) on a push-rod LS V8.
What we like about these videos is that they often shy away from giving a finite, black-and-white answer. Instead, they give the viewer as much pertinent information as possible, and let him or her decide from there whether or not the upgrade in question is suitable for the application.
With that in mind, go ahead and click play to see if upgrading the rocker arms in your LS makes sense for your build. Actually, even if you don’t have a build, knowledge is power.
Plus, the transparent valve covers installed on this engine are awesome to behold.
Comments
Obviously not an LS but never the less very interesting!
Ya, it’s not GM’s LS engine but I actually prefer the old Chevrolet Motor Division’s small block with modern heads myself. Particularly the AFR’s like used here. The modern head design from the factory is really what makes the LS a great stock motor. A 5.3 from the junkyard has stock heads that make racing heads of 30 years ago look like scrap. The short block itself is nothing any more special than the next engine though… Back in the day, factory heads were really limited. Stick a modern head on an old SBC design and it’s a whole different animal. Nothing against the LS, I just like the slightly more compact design of the SBC and the sound the old firing order had.
Interestingly, while the LS was popular for awhile, dirt track racers tried them for a few years and have gone back to using the SBC instead. And the hot rod community is looking even further back. The old Chevrolet W series motors are starting to be the thing! The original big block Chevy… Stroker kits turning 409’s into 509’s and a lot of new aftermarket support now. Very cool to see!
Slightly more compact SBC vs LS? Having two of the same body style GM cars, one with an LT1 and the other with an LS1, I can say with complete certainty that they physical dimensions of an LS are the same or evenly maybe more compact in some areas than a small block. You also gain 6 bolt mains and lose a good 100 lbs in weight.
Not sure what planet you make your opinions from, but there are just no comparisons to be made where a SBC is a better platform than the LS is.
The W series engine might be a brief fad, but for the most part that’s all it is. That engine has some drawbacks that can’t be engineered out with modern support.
The Stage 2 Buick V6 made 120 hp/L with a 4″ bore and 2.08″ intake valve in road race trim 30 years ago … and LSX aren’t further ahead. LS is a good, cheap motor. LT has better ports but GDI.
The article ignores the metallurgy advances, and the stiffness. Floppy rockers don’t work well.
Sounds like a hallway in middle/highschool. It don’t matter what you run, it’s what you want and like. Like choosing between bbc or sbc, it’s what makes you happy.