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










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










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.

SOURCE
ARP
531 Spectrum Circle
Oxnard
CA  93030
805-278-7223
Hedman Hedders
16410 Manning Way
Cerritos
CA  90701
310-921-0404
www.hedman.com
MSD
El Paso
TX  79936
915-857-5200
www.msdignition.com
Holley Performance Products
1801 Russellville Rd.
Bowling Green, KY 42101
KY  42101
270-782-2900
www.holley.com
Barry Grant Inc.
1450 McDonald Road,
Dept. MMFF
Dahlonega
GA  30533
Milodon Inc
20716 Plummer St
Chatsworth
CA  91311
818-407-1211
COMP Cams Pertronix
440 E. Arrow Hwy.
San Dimas
CA  91773
800-827-3758
www.pertronix.com
Edelbrock
Dept. 5.0
2700 California St.
Torrance
CA  90503
310-781-2222
www.edelbrock.com
SA Engine Design
Fel Pro Performance Products
5555 Garden Grove Blvd., Dept. CHP
Westminster
CA  92683
Trick Flow Specialties (TFS)
1248 Southeast Ave.
Tallmadge
OH  44278
Flowmaster
8-00/-544-4761
www.flowmastermufflers.com
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