CFM of Airflow

EngineQuest 318B Cylinder Head

Lift (inches): Intake, stock* Intake, modified** Exhaust, stock* Exhaust, modified**
.100 66.2 65.0 54.7 56.0
.200 121.4 132.0 101.0 110.0
.300 179.0 189.0 142.0 150.5
.400 214.5 240.0 168.0 168.0
.500 226.2 278.0 174.0 178.0
.600 235.5 300.0 175.0 184.0
.700 238.0 301.0 not recorded 185.0

*Stock with 1.92-/1.625-inch valves
**Modified with 2.08-/1.600-inch valves

On The Dyno

RPM: TQ: HP:
2,500 454 216
2,600 453 224
2,700 453 233
2,800 455 242
2,900 456 252
3,000 454 260
3,100 450 266
3,200 445 271
3,300 442 277
3,400 440 285
3,500 441 294
3,600 445 305
3,700 455 320
3,800 470 340
3,900 483 359
4,000 492 374
4,100 502 392
4,200 514 411
4,300 528 432
4,400 539 451
4,500 545 467
4,600 549 481
4,700 551 493
4,800 551 504
4,900 552 515
5,000 551 525
5,100 551 535
5,200 550 545
5,300 548 553
5,400 546 561
5,500 542 567
5,600 536 571
5,700 529 575
5,800 522 577
5,900 515 579
6,000 507 580
6,100 499 579
6,200 490 578
6,300 481 577
6,400 472 575
6,500 462 572

By The Numbers

417ci Mopar Small-Block

Block: OEM 360
Bore: 4.07 inches
Stroke: 4.00 inches
CID: 417 ci
Compression ratio: 10.3:1
Crankshaft: Eagle 4340
Camshaft: COMP Cams hydraulic roller
Timing chain: Rollmaster Red series
Lifters: Scorpion hydraulic roller
Pushrods: Trend ⅜-inch, 7.2-inch long with 210 tip
Springs: PAC 1255 beehive
Installed height: 1.9 inches
Spring load, closed: 165 pounds at 1.900 inches
Spring load, open: 425 pounds at 1.250 inches
Retainer: PAC 10-degree, steel
Valve locks: COMP 10-degree plus .050 inch
Duration, intake: 250 degrees at .050
Intake lift: .663 inch
Duration, exhaust: 252 degree at .050
Exhaust lift: .594 inch
Rockers: T&D
Rocker ratio: 1.5:1
Lobe separation: 108 degrees
Installed centerline: 105.5 degrees
Ring pack: Mahle Clevite 1/16-,1/16-, 3/16-inch
Ring endgap: .018-inch top, .024-inch second
Piston: Icon PN 745, dished
Piston clearance: 0.0055 inch
Main fasteners: ARP studs
Rods: Scat 6.123-inch I-beam
Main bearings: Clevite HG
Rod bearings: Clevite HNK
Main journal diameter: 2.810 inches
Rod journal diameter: 2.125 inches
Main clearance: .0025 inch
Rod clearance: .0025 inch
Cylinder heads: EngineQuest CH318B
Chamber volume: 59 cc
Head fasteners: Fel-Pro head bolts
Intake manifold: Edelbrock SuperVictor
Intake port flow: 303 cfm at .600
Exhaust port flow: 193 cfm at .600
Intake valve: Manley Severe Duty, 2.08 inches
Exhaust valve: Manley Severe Duty, 1.60 inches
Cylinder head gaskets: Fel-Pro 519SD (.044 inch)
Piston/head clearance: .050 inch
Engine gaskets: Fel-Pro
Fuel delivery: COMP Cams EZ-EFI 1,000 cfm
Carb spacer: none
Header: Schoenfeld 1⅝ to 1¾, stepped
Coil: MSD
Ignition: MSD 6AL-2
Spark plug wires: MSD Superconductor
Damper: CAT
Water pump: NAPA OEM
Oil pan: SKMFX, custom aluminum oil pan
Oil pump: Melling M72
Oil: AMSOIL 15w50
Fuel: unleaded, VP Racing Fuels VP100

On The Bench: EngineQuest Magnum Heads

EngineQuest's Magnum heads (PN 318B) and its LA-Series counterpart (the 318A) are iron replacement-style cylinder heads designed to bolt in place of tired or cracked originals. Fortunately, EngineQuest invested the effort to substantially improve on the factory design through a process of detail refinement rather than radical design changes. What results is a head that does double duty, serving as an economical replacement for OEM, while supporting the needs of a low-cost mild performance unit. The heads are cast in Australia, using a technique that produces an exceptionally smooth port surface for more flow and power, with 172cc intake runners and 62cc combustion chambers. In box-stock form, these heads offer superior quality at an affordable price with no additional machining, porting, or polishing required.

While the EngineQuest heads represent a bolt-on upgrade to a stock cylinder head, there is always room for improvement with custom porting work and modification. SKMFX explored the potential of these heads with a determined development effort to see how much airflow could be unlocked from these modest castings. The results were dramatic, as seen in the flow table below. While the modified flow numbers from SKMFX are among the best we have ever seen for a production-style head, the "as-cast" flow numbers are also very impressive. This range of flow numbers represent the potential on tap, depending upon the level of modification performed. For more information about EQ's Magnum Cylinder heads, call 800-426-8771 or log on to www.EngineQuest.com.

SOURCE
SKMFX Engines
613-931-2157
www.SKMFX.com