Competition Cams Dyno Charts

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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
1000-5000RPM
DUR 206 / 212
LIFT 480/487

Max Torque 417 ftlbs @ 3700 RPM
Max Horsepower 333 HP @ 4700 RPM
Vacuum 19.5" Hg @ 800 RPM
21" Hg @ 1000 RPM

Max Torque 413 ftlbs @ 3700 RPM
Max Horsepower 325 HP @ 4400 RPM
Vacuum 17" Hg @ 800 RPM
18" Hg @ 1000 RPM

XE256H
1000-5200RPM
DUR 212 / 218
LIFT 462/469

XR264HR
1200-5200RPM
DUR 212 / 218
LIFT 487/495

Max Torque 411 ftlbs @ 3600 RPM
Max Horsepower 330 HP @ 4700 RPM
Vacuum 18.5" Hg @ 800 RPM
20" Hg @ 1000 RPM

Max Torque 421ftlbs @ 4000 RPM
Max Horsepower 335 HP @ 4900 RPM
Vacuum 15.5" Hg @ 800 RPM
17" Hg @ 1000 RPM

XE262H
1300-5600RPM
DUR 218 / 224
LIFT 462/469

XR270HR
1600-5400RPM
DUR 218 / 224
LIFT 495/502

Max Torque 415 ftlbs @ 3700 RPM
Max Horsepower 348 HP @ 5300 RPM
Vacuum 17.5" Hg @ 800 RPM
18.5" Hg @ 1000 RPM

Max Torque 415 ftlbs @ 3800 RPM
Max Horsepower 342 HP @ 5100 RPM
Vacuum 15" Hg @ 800 RPM
16.5" Hg @ 1000 RPM

XE268H
1600-5800RPM
DUR 224 / 230
LIFT 477/480

XR276HR
1900-5600RPM
DUR 224 / 230
LIFT 502/510

Max Torque 413 ftlbs @ 3800 RPM
Max Horsepower 342 HP @ 5000 RPM
Vacuum 15.5" Hg @ 800 RPM
17" Hg @ 1000 RPM

Max Torque 427 ftlbs @ 3700 RPM
Max Horsepower 373 HP @ 5200 RPM
Vacuum 12" Hg @ 800 RPM
14" Hg @ 1000 RPM

XE274H
1800-6000RPM
DUR 230 / 236
LIFT 487/490

XR282HR
2200-5800RPM
DUR 230 / 236
LIFT 510/520

Max Torque 410 ftlbs @ 3900 RPM
Max Horsepower 369 HP @ 5900 RPM
Vacuum 11" Hg @ 800 RPM
14" Hg @ 1000 RPM

Max Torque 385 ftlbs @ 3900 RPM
Max Horsepower 402 HP @ 6100 RPM
Vacuum 9" Hg @ 800 RPM
11.5" Hg @ 1000 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
2500-6000RPM
DUR 236 / 242
LIFT 520/540

XE284H
2300-6500RPM
DUR 240 / 246
LIFT 507/510

Max Torque 385 ftlbs @ 3700 RPM
Max Horsepower 406 HP @ 6100 RPM
Vacuum 9.5" Hg @ 800 RPM
12" Hg @ 1000 RPM

Max Torque 377 ftlbs @ 3900 RPM
Max Horsepower 390 HP @ 5800 RPM
Vacuum 8" Hg @ 800 RPM
10.5" Hg @ 1000 RPM

XR294HR
2800-6100RPM
DUR 242 / 248
LIFT 540/562

XR300HR
3200-6200RPM
DUR 248 / 254
LIFT 562/580

Max Torque 380 ftlbs @ 4100 RPM
Max Horsepower 420 HP @ 6100 RPM
Vacuum 8" Hg @ 800 RPM
10.5" Hg @ 1000 RPM

Max Torque 380 ftlbs @ 4000 RPM
Max Horsepower 426 HP @ 6200 RPM
Vacuum 6.5" Hg @ 800 RPM
9" Hg @ 1000 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

FAQ about Competetion Cams brand Camshafts.