Words And Photos: Jeff Smith

Everybody knows how strong the basic LS engine package is – especially the valvetrain. For even mild street engines living in the 2,500 to 6,000 rpm world, all it takes to make more power is a bigger cam, a set of valve springs and pushrods, and let the added power rock and roll. When dealing with older small- or big-block Chevy engines, another requirement was to pony up for a complete set of roller rocker arms to replace those spindly, stamped-steel pieces. But the 21^st Century LS engine comes from the factory with a roller trunnion – what could be better?

Well, it turns out there is something better – and the cost is easily half of a new set of roller rocker arms. All you really need to do is upgrade the stock investment cast rockers with a stronger trunnion and bearing set. COMP has offered these upgraded trunnions for several years, but converting them was a bit of a tussle. You had to build a custom i.d. guide to carefully remove and replace the pressed-in bearings. But recently Powerhouse has come up with a slick little tool that makes that job easy enough that anyone with a vise (or even a C-clamp) can do the job in their garage on a Saturday afternoon.

The stock LS rocker arms are an excellent design – light, and compact, with a 1.7:1 rocker ratio. If there is a weak area, it’s the stock trunnion with its non-caged bearings. COMP covers that with an upgraded trunnion and superior caged roller bearings that easily press into place using the Powerhouse tool. The large receiver end is fitted with a heavy magnet that holds it in place in a vise, allowing you to concentrate on removing and replacing the new trunnion and bearings. The whole conversion process requires about 45 minutes or less. With the new trunnions in place, re-installing the converted rockers on the engine is also easy because you don’t have to adjust lifter preload. All LS engines are of a net lash design where simple torque will properly position the lifter and you’re ready to go. It doesn’t get much easier and you now have the peace of mind of knowing the factory rockers can handle that extra rpm.

Parts List

Sources

COMP Cams
compcams.com

Powerhouse Products
powerhouseproducts.com