One word of caution relative to degree wheels. The DC degree wheel (P4286552) is a zero-to-180 design, which will yield the numbers listed above. Other manufacturers carry 0-degrees-90-degrees-0-degrees design degree wheels, which will not directly yield the numbers above. For example, the 130 degrees on the DC wheel would be 50 degrees on the other style. The correct answer is obtained by subtracting 50 degrees from 180 degrees for 130 degrees or by subtracting 50 degrees from 90 degrees (answer 40 degrees and adding this to 90 degrees (40 degrees + 90 degrees = 130 degrees). Using the DC degree wheel eliminates a lot of confusion and lessens the possibility of making errors.
Note: Degree Tape P4120993; 'A' offset keys new PN P4286500; B, RB HEMI offset bushing P3690936.
The cam chart that lists the various cams sold by the Direct Connection in the last few years follows. It is based on rocker ratios of LA-1.5, B-RB-1.5, Hemi-1.57I, 1.52E.
Design Cam Int. Lift @ Centerline Valve Lash Engine Cam Kit # Cam I.D. Duration Valve @ Retainer Intake Exhaust --------------------------------------------------------------------------------------------------------------- 6 Cyl. P4120243 D.C. 244-108 244 .436" 102 .010 .020 6 Cyl. P3690766 SS14-112 268 .450" 108 .016 .020 6 Cyl. P3690768 ST21-110 286 .520" 108 .016 .020 A Eng. P3412044 68 340 Man.-114 276/284 .444/.453" 112 Zero A Eng. P3690213 Street Hemi GT-112 284 .471/.474" 109 Zero A Eng. P3690769 SSH-44-108 292 .510" 110 Zero A Eng. P4007619 SSH-25/44 286/292 .485/.510" 108 Zero A Eng. P4007275 C. D. Stock "Cheater" 336/348 .462/.473 108 Zero A Eng. P4120231 D.C. 284-108 284 .484" 108 Zero A Eng. P4120231 D.C. 292-108 292 .509" 108 Zero A Eng. P3412016 ST21-108 286 .520" 110 .018 .022 A Eng. P2836146 STX21-105 306 .560" 105 .028 .032 A Eng. P4120653 D.C. 284-112 284 .542" 110 .028 .032 A Eng. P4120655 D.C. 296-110 296 .572" 108 .028 .032 A Eng. P4120657 D.C. 312-106 312 .606" 104 .028 .032 A Eng. P4120148 D.C. 320-102 320 .630" 100 .024 .028 A Eng. P3690795 R280-427-1 10 Crane *280 .640" 108 A Eng. P3690589 Magna. Velocity-110 324 .633" 110 .024 .028 A Eng. P4007278 R-278-284-.413-.427-06 *278/284 .620/.640" 106 .035 .035 Cam Dyn. A Eng. P4007509 R-284,427-05 Cam Dyn. *284 *284 108 .035 .035 A Eng. P3690796 R-296-4778-1 10 Crane *296 .717" 109 .024 .028 B Eng. P3690214 Street Hemi Gr.-108 284 .471/.474" 106 Zero B Eng. P3412073 SSH-25-108.5 286 .485" 108 Zero B Eng. P3690812 SSH-44-108 292 .510" 106 Zero B Eng. P4007277 C.D. Stock "Cheater" 352/380 .467/.483 108 Zero B Eng. P4120235 D.C. 284-108 284 .484" 108 Zero B Eng. P4120237 D.C. 292-108 292 .509" 108 Zero B Eng. P3690816 Stage 11-115 300/308 .518" 110 .028 .032 B Eng. P4120659 D.C. 284-112 284 .528" 110 .028 .032 B Eng. P4120661 D.C. 296-110 296 .557" 108 .028 .032 B Eng. P4120663 D.C. 312-106 312 .590" 104 .028 .032 B Eng. P3690159 STX-22 310 .590" 108 .028 .032 B Eng. P3690588 Mini Express-107 316 .654" 107 .024 .028 B Eng. P4120042 R280-.4468-08 Crane *280 .670" 108 .035 .035 B Eng. P4007279 R286-500-108 Cam Dyn. *286 .750" 107 .035 .035 Hemi P3690814 SSH-44-108 292 .510" 106 Zero Hemi P4007945 C.D. Stock "Cheater" 342/348 .490/.480" 103 Zero Hemi P3412090 STX22-105 310 .590" 104 .028 .032 Hemi P3571029 725-105 340 .643/.623" 103 .028 .032 Hemi P3690587 Mini Express-104 324 .684/.663" 103 .024 .028 Hemi P3690591 R-290-446-104- Crane *290 .700/.678" 103 .028 .032 Hemi P4007253 R292-500-106 Cam Dyn. 0292 .785/.760" 103 .032 .032 Hemi P3690839 R-296-4778-108 Crane *296 .750/.726" 108 .032 .032 ---------------------------------------------------------------------------------------------------------------
DESIGN REC. LIFT @ INSTALLATION VALVE LASH ENGINE CAM KIT # CAM I.D. DURATION OVERLAP VALVE CENTERLINE INTAKE EXHAUST --------------------------------------------------------------------------------------------------------------- 6 CYL P4286679 D.C. 268-108 268 52 .460" 104 .016 .020 6 CYL P4286681 D.C. 276-106 276 64 .490" 102 .016 .020 A Eng. P4286667 D.C. 248-114 248 20 .410" 112 Zero A Eng. P4286669 D.C. 260-113 260 34 .430" 110 Zero A Eng. P4286671 D.C. 272-112 272 48 .455 108 Zero A Eng. P4286630 D.C. 280-110 280 60 .474" 106 Zero A Eng. P4349266 D. C. 324-106 324 - .620" 104 .028 .032 A Eng. P4349245 Stock Cheater-360 H.P.-106 - - Stock 106 Zero A Eng. P4349243 Stock Cheater-340-106 - - Stock 104 Zero A Eng. P4120975 Super Stock- Roller-360-106 309/316 - .630/.650" 106 .035 .035 A Eng. P4120976 Super Stock- Roller-340-106 310/312 - .620/.638" 104 .035 .035 A Eng. P4120977 Mod. Prod. Roller-340-109 323/330 - .690/.630" 107 .035 .035 B Eng. P4286673 D.C.-248-114 248 20 .410" 112 Zero B Eng. P4286675 D.C.-260-113 260 34 .430" 110 Zero B Eng. P4286677 D.C.-272-112 272 48 .455" 108 Zero B Eng. P4286631 D. C. -280-110 280 60 .474" 106 Zero B Eng. P4349268 D.C.-324-106 324 - .620" 104 .028 .032 P3690588 Mini-Express-107 316 - .654" 107 .024 .028 B Eng. P4349270 D.C.-328-107 328 - .690" 107 .024 .028 B Eng. P4349249 Stock Cheater- Hyd.- 108 - - Stock 106 Zero B Eng. P4349247 Super Stock- Roller- 108 324 - .750" 106 .035 .035 Hemi P4349259 278 Hyd.-108 278 - .495/.480" 104 Zero Hemi P4349257 292 Hyd.-108 292 - .524/.507" 104 Zero Hemi P4349251 Stock Cheater- Hyd.- 106 - - Stock 104 Zero Hemi P4349253 Super Stock-Roller-106 333 - .785" 104 .032 .032 Hemi P4349255 Pro Stock-Roller-114 328/344 - .747/.700" 114 .028 .030 ---------------------------------------------------------------------------------------------------------------
The first thing to do and the most important item in the valve gear is the cam selection. That is done by the racer for his application. Recommendations are given in other chapters, books and the D.C. catalog.