SCORE Journal - The Official Publication of SCORE Off-Road Racing
Issue link: http://read.uberflip.com/i/693984
5.3L LM7 CAM TEST- STOCK VS LS9 VS 224 CRANE This graph illustrates the amazing power gains offered by swapping a cam on an otherwise stock 5.3L LM7 on the engine dyno. The test involved running the stock motor with the stock 5.3L cam, an LS9 cam (the most powerful factory offering) and a Crane cam offering .590 lift, a 224/232-degree duration split and 115-degree lobe separation angle. The stock 5.3L heads were set up with a dual valve spring package from Brian Tooley Racing to allow the larger cams. Equipped with the stock 5.3L cam, the fuel injected 5.3L (with headers and no accessories) produced 353 hp at 5,200 rpm and 384 lb-ft of torque at 4,300 rpm. After installation of the LS9 cam, the power numbers jumped LS3 CAM TEST-STOCK VS BTR STAGE 3 CAM Like the 5.3L, the larger (aluminum) LS3 will benefit from the proper cam swap. It bears mentioning that the factory LS3 cam was already much more powerful than the 5.3L cam tested in graph 1, but even so, the BTR Stage 3 cam (and springs) increased the power output of the otherwise stock LS3 crate motor from 496 hp at 5,900 rpm and 491 lb-ft of torque at 4,700 rpm to 570 hp at 6,500 rpm and 522 lb- ft of torque at 5,300 rpm. The BTR cam increased the power output through the entire rev range, no easy task with a stock cam at the lower rpm ranges. to 419 hp at 6,200 rpm and 394 lb-ft at 5,000 rpm. Note that the 5.3L lost power with the LS9 cam ,up to 4,500 rpm compared to the LM7, but pulled away rapidly up to 6,500 rpm. The Crane 224 cam pushed thing up even further to 442 hp at 6,200 rpm and 412 lb-ft at 5,000 rpm. The Crane bettered the LS9 cam through the entire rev range, but lost out slightly to the LM7 cam below 2,900 rpm. Once equipped with the 224 Crane cam, the motor was in need of ported heads and/or a different intake manifold (like a Fast LSXR). POWER PRODUCTION MADE SIMPLE 084 SCORE JOURNAL