SINGLE PLANE | ||||||||
107º LSA | 110º LSA | 113º LSA | ||||||
Avg. torque | 495 lb-ft | Avg. torque | 491 lb-ft | Avg. torque | 481 lb-ft | |||
Avg. power | 456 hp | Avg. power | 452 hp | Avg. power | 445 hp | |||
RPM | LB-FT | HP | RPM | LB-FT | HP | RPM | LB-FT | HP |
2,500 | 419 | 199 | 2,500 | 417 | 198 | 2,500 | 386 | 184 |
2,600 | 420 | 208 | 2,600 | 417 | 206 | 2,600 | 392 | 194 |
2,700 | 424 | 218 | 2,700 | 421 | 216 | 2,700 | 399 | 205 |
2,800 | 431 | 230 | 2,800 | 426 | 227 | 2,800 | 404 | 215 |
2,900 | 439 | 243 | 2,900 | 430 | 238 | 2,900 | 407 | 224 |
3,000 | 449 | 256 | 3,000 | 439 | 250 | 3,000 | 417 | 238 |
3,100 | 456 | 269 | 3,100 | 451 | 266 | 3,100 | 428 | 253 |
3,200 | 461 | 281 | 3,200 | 459 | 280 | 3,200 | 438 | 267 |
3,300 | 465 | 292 | 3,300 | 464 | 292 | 3,300 | 452 | 284 |
3,400 | 468 | 303 | 3,400 | 467 | 302 | 3,400 | 456 | 295 |
3,500 | 471 | 314 | 3,500 | 468 | 312 | 3,500 | 460 | 307 |
3,600 | 478 | 327 | 3,600 | 474 | 325 | 3,600 | 465 | 319 |
3,700 | 485 | 342 | 3,700 | 483 | 340 | 3,700 | 471 | 332 |
3,800 | 491 | 355 | 3,800 | 487 | 352 | 3,800 | 473 | 342 |
3,900 | 495 | 367 | 3,900 | 488 | 362 | 3,900 | 473 | 351 |
4,000 | 498 | 380 | 4,000 | 492 | 375 | 4,000 | 479 | 365 |
4,100 | 506 | 395 | 4,100 | 499 | 389 | 4,100 | 484 | 378 |
4,200 | 514 | 411 | 4,200 | 507 | 405 | 4,200 | 491 | 393 |
4,300 | 520 | 426 | 4,300 | 516 | 423 | 4,300 | 499 | 409 |
4,400 | 526 | 441 | 4,400 | 521 | 437 | 4,400 | 505 | 423 |
4,500 | 528 | 452 | 4,500 | 524 | 449 | 4,500 | 512 | 438 |
4,600 | 533 | 467 | 4,600 | 527 | 462 | 4,600 | 519 | 455 |
4,700 | 535 | 479 | 4,700 | 531 | 475 | 4,700 | 523 | 468 |
4,800 | 539 | 492 | 4,800 | 534 | 488 | 4,800 | 526 | 481 |
4,900 | 541 | 505 | 4,900 | 536 | 500 | 4,900 | 529 | 494 |
5,000 | 543 | 517 | 5,000 | 538 | 512 | 5,000 | 529 | 504 |
5,100 | 543 | 528 | 5,100 | 540 | 524 | 5,100 | 531 | 515 |
5,200 | 543 | 537 | 5,200 | 539 | 534 | 5,200 | 530 | 524 |
5,300 | 541 | 546 | 5,300 | 538 | 542 | 5,300 | 530 | 535 |
5,400 | 539 | 554 | 5,400 | 537 | 552 | 5,400 | 530 | 545 |
5,500 | 537 | 562 | 5,500 | 535 | 560 | 5,500 | 528 | 553 |
5,600 | 534 | 569 | 5,600 | 532 | 567 | 5,600 | 525 | 560 |
5,700 | 531 | 576 | 5,700 | 528 | 573 | 5,700 | 523 | 567 |
5,800 | 527 | 582 | 5,800 | 525 | 580 | 5,800 | 520 | 574 |
5,900 | 524 | 588 | 5,900 | 522 | 586 | 5,900 | 517 | 581 |
6,000 | 519 | 593 | 6,000 | 517 | 590 | 6,000 | 513 | 586 |
6,100 | 514 | 597 | 6,100 | 513 | 595 | 6,100 | 508 | 590 |
6,200 | 508 | 600 | 6,200 | 508 | 599 | 6,200 | 503 | 594 |
6,300 | 502 | 602 | 6,300 | 502 | 602 | 6,300 | 499 | 598 |
6,400 | 497 | 605 | 6,400 | 496 | 605 | 6,400 | 494 | 602 |
6,500 | 490 | 606 | 6,500 | 490 | 607 | 6,500 | 489 | 605 |
6,600 | 483 | 607 | 6,600 | 484 | 609 | 6,600 | 483 | 607 |
6,700 | 476 | 607 | 6,700 | 476 | 607 | 6,700 | 477 | 608 |
6,800 | 469 | 607 | 6,800 | 459 | 595 | 6,800 | 468 | 605 |
6,900 | 459 | 603 | 6,900 | 444 | 584 | 6,900 | 453 | 595 |
7,000 | 445 | 594 | 7,000 | 434 | 579 | 7,000 | 441 | 587 |
7,100 | 437 | 591 | 7,100 | 425 | 574 | 7,100 | 428 | 579 |
This magazine article testing produces some unexpected results, however the benefit of a duel plane manifold is clearly seen looking at the torque curve.
The following I have taken from my old site and is a collection of camshaft information , mainly comparing Comp cams to one another.
While the images are not appearing, if you click on them it will take you to the original image.
You will discover the shorter the @ .050" duration the more low RPM power will be made.
LOBE SEPARATION ANGLE EFFECTS | |
NARROWER LSA | WIDER LSA |
Increased overlap | Reduced overlap |
Increased low-rpm torque | Improved top-end power |
Narrower powerband | Wider powerband |
Reduced idle quality and vacuum | Improved idle quality |
Increased cranking compression | Reduced cranking compression |
Decreased piston-to-valve clearance | Increased piston-to-valve clearance |
406 STROKER SPECS | |
Displacement | 406.0 ci |
Bore x stroke | 4.155 x 3.750 |
Rotating assembly | Probe forged steel crank |
and rods | |
Pistons | Probe forged |
Heads | Dart Pro 1 227 CNC |
Compression | 11.1:1 |
CAMSHAFT 1 | ||
107º LSA Comp Cams Hydraulic Roller | ||
PN | 12-000-8 | |
Grind No. | CS 3318S/3319S HR107+4 | |
Gross valve lift | 0.562/0.580 intake/exhaust | |
Valve lift w/ 1.6 rockers | 0.600/0.619 intake/exhaust | |
Duration at 0.050 | 248/254 intake/exhaust | |
Valve timing (@ 0.050 lift) | Open | Close |
Intake | 21 BTDC | 47º ABDC |
Exhaust | 58 BBDC | 16º ATDC |
Vacuum at 1,000 rpm | 6 in |
CAMSHAFT 2 | ||
110º LSA Comp Cams Hydraulic Roller | ||
PN | 12-444-8 | |
Grind No. | XR300HR | |
Gross valve lift | 0.562/0.580 intake/exhaust | |
Valve lift w/ 1.6 rockers | 0.600/0.619 intake/exhaust | |
Duration at 0.050 | 248/254 intake/exhaust | |
Valve timing (@ 0.050 lift) | Open | Close |
Intake | 18 BTDC | 50º ABDC |
Exhaust | 61 BBDC | 13º ATDC |
Vacuum at 1,000 rpm | 7 in |
CAMSHAFT 3 | ||
113º LSA Comp Cams Hydraulic Roller | ||
PN | 12-000-8 | |
Grind No. | CS 3318S/3319 HR113+4 | |
Gross valve lift | 0.562/0.580 intake/exhaust | |
Valve lift w/ 1.6 rockers | 0.600/0.619 intake/exhaust | |
Duration at 0.050 | 248/254 intake/exhaust | |
Valve timing (@ 0.050 lift) | Open | Close |
Intake | 15 BTDC | 53º ABDC |
Exhaust | 64 BBDC | 10º ATDC |
Vacuum at 1,000 rpm | 8 in |
The numbers: Dual Plane vs. Single plane
DYNO DETAILS | |
Carburetor | Holley 950 Ultra HP 75/79 jets with 1-in open spacer |
Ignition | MSD 7AL Digital |
Headers | Hedman 1 3/4-in long-tubes with 18-in extensions |
Fuel | 91-octane unleaded |
Timing | 37 |
Intake manifold | Dart dual-plane |
DUAL PLANE | ||||||||
107º LSA | 110º LSA | 113º LSA | ||||||
Avg. torque | 492 lb-ft | Avg. torque | 485 lb-ft | Avg. torque | 480 lb-ft | |||
Avg. power | 449 hp | Avg. power | 442 hp | Avg. power | 439 hp | |||
RPM | LB-FT | HP | RPM | LB-FT | HP | RPM | LB-FT | HP |
2,500 | 417 | 198 | 2,500 | 409 | 194 | 2,500 | 397 | 189 |
2,600 | 419 | 207 | 2,600 | 411 | 203 | 2,600 | 398 | 197 |
2,700 | 429 | 220 | 2,700 | 420 | 216 | 2,700 | 408 | 210 |
2,800 | 444 | 237 | 2,800 | 433 | 231 | 2,800 | 421 | 225 |
2,900 | 458 | 253 | 2,900 | 448 | 247 | 2,900 | 435 | 240 |
3,000 | 467 449 | 267 | 3,000 | 459 | 262 | 3,000 | 446 | 255 |
3,100 | 477 | 282 | 3,100 | 470 451 | 277 | 3,100 | 455 | 269 |
3,200 | 482 | 294 | 3,200 | 477 | 291 | 3,200 | 464 438 | 283 |
3,300 | 485 | 305 | 3,300 | 481 | 302 | 3,300 | 471 | 296 |
3,400 | 488 | 316 | 3,400 | 485 | 314 | 3,400 | 475 | 308 |
3,500 | 494 | 329 | 3,500 | 489 | 326 | 3,500 | 479 | 319 |
3,600 | 501 | 343 | 3,600 | 495 | 339 | 3,600 | 485 | 333 |
3,700 | 510 | 360 | 3,700 | 502 | 353 | 3,700 | 492 | 346 |
3,800 | 518 | 375 | 3,800 | 509 | 368 | 3,800 | 498 | 361 |
3,900 | 524 | 389 | 3,900 | 514 | 381 | 3,900 | 504 | 374 |
4,000 | 529 | 403 | 4,000 | 520 | 396 | 4,000 | 508 | 387 |
4,100 | 534 | 417 | 4,100 | 525 | 410 | 4,100 | 513 | 400 |
4,200 | 537 | 429 | 4,200 | 529 | 423 | 4,200 | 518 | 414 |
4,300 | 539 | 441 | 4,300 | 532 | 435 | 4,300 | 521 | 427 |
4,400 | 539 | 452 | 4,400 | 532 | 446 | 4,400 | 523 | 438 |
4,500 | 538 | 461 | 4,500 | 532 | 456 | 4,500 | 523 | 448 |
4,600 | 540 | 473 | 4,600 | 533 | 467 | 4,600 | 525 | 460 |
4,700 | 540 | 483 | 4,700 | 533 | 477 | 4,700 | 525 | 470 |
4,800 | 540 | 493 | 4,800 | 533 | 487 | 4,800 | 526 | 481 |
4,900 | 539 | 503 | 4,900 | 533 | 497 | 4,900 | 526 | 491 |
5,000 | 538 | 512 | 5,000 | 531 | 506 | 5,000 | 526 | 500 |
5,100 | 536 | 521 | 5,100 | 530 | 515 | 5,100 | 524 | 509 |
5,200 | 534 | 529 | 5,200 | 529 | 523 | 5,200 | 522 | 517 |
5,300 | 532 | 536 | 5,300 | 526 | 531 | 5,300 | 520 | 525 |
5,400 | 529 | 544 | 5,400 | 524 | 539 | 5,400 | 518 | 532 |
5,500 | 524 | 549 | 5,500 | 520 | 544 | 5,500 | 515 | 539 |
5,600 | 519 | 554 | 5,600 | 516 | 550 | 5,600 | 512 | 546 |
5,700 | 514 | 558 | 5,700 | 511 | 554 | 5,700 | 507 | 550 |
5,800 | 510 | 563 | 5,800 | 505 | 558 | 5,800 | 502 520 | 554 |
5,900 | 503 | 565 | 5,900 | 499 | 561 586 | 5,900 | 496 | 557 |
6,000 | 496 | 566 593 | 6,000 | 494 | 564 | 6,000 | 492 | 562 |
6,100 | 488 | 566 | 6,100 | 485 | 564 | 6,100 | 485 | 563 |
6,200 | 480 | 567 | 6,200 | 479 | 566 | 6,200 | 477 | 564 |
6,300 | 473 | 568 | 6,300 | 472 | 566 | 6,300 | 470 | 564 |
6,400 | 466 | 568 | 6,400 | 463 | 565 | 6,400 | 463 | 564 |
6,500 | 458 | 567 | 6,500 | 455 | 563 | 6,500 | 456 | 564 |
6,600 | 450 | 566 | 6,600 | 448 | 562 | 6,600 | 447 | 562 |
6,700 | 441 | 563 | 6,700 | 435 | 555 | 6,700 | 439 | 560 |
6,800 | 433 | 561 | 6,800 | 417 | 540 | 6,800 | 430 | 557 |
6,900 | 421 | 553 | 6,900 | 400 | 526 | 6,900 | 419 | 550 |
7,000 | 408 | 544 | 7,000 | 389 | 518 | 7,000 | 400 | 533 |
7,100 | 397 | 537 | 7,100 | 379 | 513 | 7,100 | 386 | 522 |
Competition Cams Dyno Charts
CLICK ON CHARTS TO ENLARGE AND REVIEW DETAILS
Tested with Chevrolet 350 Small Block
Bore+4.040" Stroke=3.480" 9.25:1Compression ratio
Dart S/R Heads Edelbrock Performer Manifold
Holley #3310 Vac. Sec. Carb 1 5/8" Headers
HYDRAULIC FLAT TAPPET | HYDRAULIC ROLLER TAPPET |
With a short duration camshaft, a flat tappet style will make more power. This is because the advertised duration is longer on a roller cam, (same @ .050" lift spec) so that it can absorb the store energy(inertia) in the heavier hydraulic roller lifter, before it begins lifting it aggressively. This extra duration reduces cylinder pressure and therefore reduces power.
Once the duration becomes longer the benefits of a fast lifting hydraulic roller out way the lower cylinder pressure by making it back up with increased flow.
The factory engines use hydraulic roller camshaft for warranty reasons, greater reliabilty, not for making more power. A roller needs work to do, long duration, high lift, a small cam just doesn't benefit from a roller.
I have custom cams ground by Bullet. They offer a much wider selection of profiles, more specificlly engineering for each application. The cost about $50 more than a Comp Cams off the shelf cam.
XE250H 600-4600RPM DUR 206 / 212 LIFT 432/444 |
XR258HR |
Max Torque 417 ftlbs @ 3700 RPM |
Max Torque 413 ftlbs @ 3700 RPM |
XE256H |
XR264HR |
Max Torque 411 ftlbs @ 3600 RPM |
Max Torque 421ftlbs @ 4000 RPM |
XE262H 1300-5600RPM DUR 218 / 224 LIFT 462/469 |
XR270HR |
Max Torque 415 ftlbs @ 3700 RPM |
Max Torque 415 ftlbs @ 3800 RPM |
XE268H (S/R Heads) 1600-5800RPM DUR 224 / 230 LIFT 477/480 |
XR276HR(Sportman Heads) 1900-5600RPM |
Max Torque 413 ftlbs @ 3800 RPM |
Max Torque 427 ftlbs @ 3700 RPM |
12Hg vacuum is enough for most power brakes, dropping to 10Hg is probably not enough. Electric Vacuum Pumps offer a solution.
XE274H 1800-6000RPM DUR 230 / 236 LIFT 487/490 |
XR282HR |
Max Torque 410 ftlbs @ 3900 RPM |
Max Torque 385 ftlbs @ 3900 RPM |
________________________________________________________________
Tested with Chevrolet 350 Small Block
Bore=4.040" Stroke=3.480" 9.25:1Compression ratio
Sportsman II Heads Edelbrock Victor Jr Manifold
Holley 750 dbl. pmper Carb 1 3/4" Headers
XR288HR |
XE284H |
Max Torque 385 ftlbs @ 3700 RPM |
Max Torque 377 ftlbs @ 3900 RPM |
XR294HR |
XR300HR |
Max Torque 380 ftlbs @ 4100 RPM |
Max Torque 380 ftlbs @ 4000 RPM |
XE294H 2800-7000RPM DUR 250 / 256 LIFT 519/523 |
Max Torque 394 ftlbs @ 4100 RPM
Max Horsepower 415 HP @ 5800 RPM
Vacuum 9.5" Hg @ 800 RPM
11.5" Hg @ 1000 RPM