The horsepower game is all about escalation. Everyone knows that the LS engines are the easiest path to big horsepower. But that also means bigger cams and higher engine speeds, and all that puts a strain on valvetrain parts. The stock LS rocker arm is a wonderful piece of engineering. It’s light, small, and very rigid with a 1.7:1 rocker ratio. It’s even blessed with a needle bearing fulcrum. But it’s that stock fulcrum that is the weakest link in the chain. One budget way to improve these rockers is a conversion kit that will replace the stock fulcrum with a more much robust steel piece along with new roller bearings. Until now, the hassle has been making the homemade tools to remove the old parts and install the new ones.
Summit Racing has come up with an elegant tool that solves that pressing problem. Summit’s domestic-built Rocker Arm Trunnion tool is a nicely engineered piece that makes the conversion really simple. Combine that with a Summit LS Rocker Arm Bearing upgrade kit and you can upgrade your valvetrain. Consider that a set of aftermarket aluminum rocker arms for an LS will easily double that investment. This saves enough coin that you can easily justify upgrading the pushrods and valvesprings as well.
01. A great budget valvetrain upgrade for any LS engine is to improve the trunnion strength on a stock LS rocker arm with Summit Racing’s upgrade kit that’s easy to install.
02. The upgrade kit includes high-tensile-strength steel trunnions that are mated to a pair of needle roller bearing assemblies and retained by large snap rings. The replacement trunnion is much stronger than the factory piece and greatly increases rocker arm stability.
03. What makes this installation easy is the Summit Racing Trunnion and Bearing Installation/Removal kit. The large black vise fixture is held in place with a pair of very small magnets (foreground). The hollow end cap and mandrel work together to align the needle bearings with the rocker body.
04. With the rockers removed from the engine, place the two small magnets in the holes on the backside of the fixture and position it on the vise. Place the hollow portion of the black end cap over one side of the stock rocker arm and slowly close the vise. This will remove the stock bearings and trunnion.
05. Place a new roller bearing over one end of the mandrel and the hollow end of the black cap on the other. Then place the spacer next to the bearing.
06. Place the mandrel assembly into a bare rocker and press the new bearing into place.
07. Coat both bearings with assembly lube and then slide a new trunnion inside the bearing in the rocker. Slide the trunnion out enough to engage the new bearing and position the end of the trunnion with the large washer. Make sure the trunnion moves easily as you press the assembly into the rocker.
08. Use a pair of expanding snap ring pliers to install the large snap rings over each end of the trunnion and there you have it: an assembled rocker. Summit’s spec is total endplay of 0.005-0.010-inch. Total assembly time is less than 45 minutes.
09. Replacing the rockers is just as easy although this would be a great time to add new springs or at least stronger pushrods. Make sure the flat, spot-faced portion of the trunnion faces up to match the washer on the factory bolt. Torque the factory bolt to 22 ft-lb and the job is complete. With the net lash system, you don’t have to set lifter preload, making the reinstallation a breeze.
|Summit LS Rocker Arm Bearing Kit||SME-143002||Summit Racing|
|Summit Rocker Trunnion Install Tool||SME-906011||Summit Racing|
|Summit LS Rocker bearing (2)||SME-143002-2B||Summit Racing|
|COMP valvespring kit, beehive||CCA-26915-16||Summit Racing|
|COMP valvespring retainers, steel||CCA-774-16||Summit Racing|
|COMP Hi-Tech pushrods, 7.400”||CCA-7955-16||Summit Racing|