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383 Chevy Engine - The Ultimate 'StickDyno-Thrashing 6 Camshafts In A Small-Block 383 From the February, 2009 issue of Chevy High Performance By Scott Crouse Photography by Scott Crouse
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Lock the garage door and break out the droplight, as this month's dyno test is all about choosing the perfectcamshaft for a 383ci stroker small-block. While the 350 may be the most popular, and the 400 more robust, the 383ci engine is still, by far, the most popular street combination. And for our testing purposes, it would unequivocally deliver robust power across a wide range of camshafts, from mild to wild. To get the job done we paired up the technical staff of Comp Cams with the guys from SA Engine Design to perform a back-to-back test of six individual camshafts. Cylinder heads of choice were 190cc Trick Flows, and we ran three separate groups of progressively bigger camshaft profiles, pairing dual-pattern grinds against single-pattern grinds. The camshafts were run with a dual-plane Edelbrock Air Gap intake manifold, a 750-cfm Speed Demon carburetor, and set of 131/44-inch Hedman headers. Each of the tests found maximum power with 34 degrees of total spark timing with an out-of-the-box Demon carburetor. Some street tuning was performed to increase idle vacuum, but overall each package delivered a useful power curve for any given audience. To provide total coverage of each camshaft and its mannerisms we also measured the cranking compression and idle vacuum. Check out the details and compare our dyno numbers carefully. High-rpm power may accelerate a dedicated strip machine to the fastest speed, but a hefty torque curve will definitely lay the stoplight smackdown on a race engine every time. Engine Specs * 383ci small-block * 4.030-inch bore * 3.75-inch stroke * 11.5:1 compression * Comp Cams valvetrain * Milodon oil pan w/windage tray * 91-octane pump gas * 160-degrees water temperature * ARP engine bolts * Fel-Pro gasket set * 190cc Trick Flow cylinder heads * 750-cfm Speed Demon * Edelbrock intake * Hedman headers * Champion spark plugs * Lucas oil 5W30 * MSD Distributor, wires, ignition  To ease the process of changing...  To ease the process of changing cams, Comp offers its durable three-piece timing cover. With the help of a camshaft installation tool, our six-way cam thrash was a breeze. Dual-Pattern | Group #1 | | | PN | 12-408-8 | | Grind | XR258HR-10 | | Intake valve lift | 0.480 inch | | Exhaust valve lift | 0.487 inch | | Intake duration at 0.050-inch lift | 206 degrees | | Exhaust duration at 0.050-inch lift | 212 degrees | | LSA | 110 | | Intake valve opening | 23 | | Intake valve closing | 55 | | Exhaust valve opening | 66 | | Exhaust valve closing | 18 | | Cranking compression | 220 psi | | Idle vacuum at 900 rpm | 17 inches | | Peak torque | 483 | | Peak horsepower | 416 | | Average torque at 2,500-5,500 rpm | 456 | | Average horspower at 2,500-5,500 rpm | 345 | | RPM | TQ | HP | | 2,500 | 440 | 209 | | 3,000 | 457 | 261 | | 3,500 | 480 | 320 | | 3,800 | 483 | 350 | | 4,000 | 482 | 367 | | 4,500 | 471 | 404 | | 5,000 | 437 | 416 | | 5,500 | 390 | 408 | | 6,000 | N/A | N/A | | 6,300 | N/A | N/A | | Group #2 | | PN | 12-423-8 | | Grind | XR276HR-10 | | Intake valve lift | 0.502 inch | | Exhaust valve lift | 0.510 inch | | Intake duration at 0.050-inch lift | 224 degrees | | Exhaust duration at 0.050-inch lift | 230 degrees | | LSA | 110 | | Intake valve opening | 32 | | Intake valve closing | 64 | | Exhaust valve opening | 75 | | Exhaust valve closing | 27 | | Cranking compression | 225 psi | | Idle vacuum at 900 rpm | 17.5 inches | | Peak torque | 486 | | Peak horsepower | 462 | | Average torque at 2,500-6,000 rpm | 455 | | Average horsepower at 2,500-6,00 0rpm | 368 | | RPM | | TQ | HP | | 2,500 | 422 | 201 | | 3,000 | 437 | 249 | | 3,500 | 472 | 315 | | 4,000 | 484 | 369 | | 4,100 | 486 | 379 | | 4,500 | 484 | 415 | | 5,000 | 470 | 448 | | 5,500 | 441 | 462 | | 6,000 | 397 | 454 | | 6,300 | N/A | N/A | | Group #3 | | PN | 12-443-8 | | Grind | XR294HR-10 | | Intake valve lift | 0.540 inch | | Exhaust valve lift | 0.562 inch | | Intake duration at 0.050-inch lift | 242 degrees | | Exhaust duration at 0.050-inch lift | 248 degrees | | LSA | 110 | | Intake valve opening | 41 | | Intake valve closing | 73 | | Exhaust valve opening | 84 | | Exhaust valve closing | 36 | | Cranking compression | 200 psi | | Idle vacuum at 900 rpm | 7.5 inches | | Peak torque | 508 | | Peak horsepower | 509 | | Average torque at 2,500-6,300 rpm | 467 | | Average horsepower at 2,500-6,300 rpm | 398 | | RPM | TQ | HP | | 2,500 | 397 | 197 | | 3,000 | 411 | 235 | | 3,500 | 465 | 310 | | 4,000 | 498 | 379 | | 4,500 | 508 | 435 | | 5,000 | 501 | 477 | | 5,500 | 480 | 503 | | 5,900 | 454 | 509 | | 6,000 | 445 | 508 | | 6,300 | 414 | 496 | Comp Cams offers more lobe... Comp Cams offers more lobe profiles than just about any other camshaft manufacture today. We dreamed the dream and Comp supplied it: the perfect 383ci camshaft. Single-Pattern | Group #1 | | PN | NA | | Grind | 3311S/3311SHR110 | | Intake valve lift | 0.480 inch | | Exhaust valve lift | 0.480 inch | | Intake duration at 0.050-inch lift | 206 degrees | | Exhaust duration at 0.050-inch lift | 206 degrees | | LSA | 110 | | Intake valve opening | -3 | | Intake valve closing | 29 | | Exhaust valve opening | 37 | | Exhaust valve closing | -11 | | Cranking compression | 220 psi | | Idle vacuum at 900 rpm | 16.5 inches | | Peak torque | 495 | | Peak horsepower | 442 | | Average torque at 2,500-5,700 rpm | 466 | | Average horsepower at 2,500-5,700 rpm | 362 | | RPM | TQ | HP | | 2,500 | 447 | 213 | | 3,000 | 462 | 264 | | 3,500 | 493 | 328 | | 3,700 | 495 | 348 | | 4,000 | 492 | 375 | | 4,500 | 484 | 415 | | 5,000 | 460 | 438 | | 5,300 | 438 | 442 | | 5,500 | 420 | 440 | | 5,700 | 402 | 437 | | Group #2 | | PN | NA | | Grind | 33145S/33145SHR110 | | Intake valve lift | 0.502 inch | | Exhaust valve lift | 0.502 inch | | Intake duration at 0.050-inch lift | 224 degrees | | Exhaust duration at 0.050-inch lift | 224 degrees | | LSA | 110 | | Intake valve opening | 6 | | Intake valve closing | 38 | | Exhaust valve opening | 46 | | Exhaust valve closing | -2 | | Cranking compression | 190 psi | | Idle vacuum at 900 rpm | 14.5 inches | | Peak torque | 488 | | Peak horsepower | 454 | | Average torque at 2,500-6,000 rpm | 453 | | Average horsepower at 2,500-6,000 rpm | 365 | | RPM | TQ | HP | | 2,500 | 431 | 205 | | 3,000 | 445 | 254 | | 3,500 | 478 | 318 | | 4,000 | 488 | 371 | | 4,500 | 484 | 415 | | 5,000 | 463 | 440 | | 5,500 | 433 | 454 | | 6,000 | 357 | 408 | | 6,300 | NA | NA | | Group #3 | | PN | N/A | | Grind | 3317S/3317SHR110 | | Intake valve lift | 0.540 inch | | Exhaust valve lift | 0.540 inch | | Intake duration at 0.050-inch lift | 242 degrees | | Exhaust duration at 0.050-inch lift | 242 degrees | | LSA | 110 | | Intake valve opening | 15 | | Intake valve closing | 47 | | Exhaust valve opening | 55 | | Exhaust valve closing | 7 | | Cranking compression | 190 psi | | Idle vacuum at 900 rpm | 9.0 inches | | Peak torque | 497 | | Peak horsepower | 498 | | Average torque at 2,500-6,300 rpm | 461 | | Average horsepower at 2,500-6,300 rpm | 392 | | | | RPM | TQ | HP | | 2,500 | 405 | 200 | | 3,000 | 410 | 234 | | 3,500 | 464 | 310 | | 4,000 | 490 | 373 | | 4,500 | 497 | 426 | | 5,000 | 491 | 468 | | 5,500 | 469 | 492 | | 6,000 | 436 | 498 | | 6,300 | 404 | 485 | Final Verdict Big cams make high-rpm power-but at the expense of low idle vacuum and poor street drivability. Small cams trade a bit of that high-end power but offer good street manners, while providing enough low-rpm torque to hang with even the biggest beast on the streets. In the end it all comes down to a trade-off between drivability and balls-out high-performance power.
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