These camshafts are for 1954–'84 big twins with either the Hydraulic Conversion kit or the Cylinder Head Replacement kit for panhead engines. They are also replacement parts for Flathead Power® P-Series and SH-Series engines. Since these kits and engines include 1984–'99 style hydraulic lifters,the larger late style roller diameter requires that cams designed for 1984–'99 models must be used to achieve correct valve timing. When choosing a late style cam for this type of engine, be aware that, due to the approximate 1.5:1 rocker ratio of most aftermarket rocker arms for shovelheads, the total valve lift will be reduced by about 9% from the specified value. The specification chart shown here shows specs as used in a pan or shovel engine. These cams are available in generator and alternator styles.
Fits:
- 1954–1965 engines with S&S Head Update kit
- 1966–1984 engines with Hydraulic Conversion kit
- P-Series and SH-Series engines
- Custom generator style engines with 1984–1999 style top end
Features and Benefits
- Quality construction – Made in-house by S&S Cycle in Viola, WI
- Higher lift and increased valve timing for better performance
- Quiet, dependable hydraulic valve train when used with S&S Hydraulic Conversion kits
Cam Specifications for 1954–’84 Big Twin Engines Requiring 1984–'99 Style Cams
|
| Cam |
Application
|
Generator Part # |
Alternator Part # |
Valve Timing1 Open/Close |
Valve Duration |
Valve Lift |
Lift @ TDC2 |
Spring Spacing Required |
Tappet Type Required |
| Intake |
Exhaust |
Intake |
Exhaust |
Intake |
Exhaust |
| 513 |
74"–84" Stock or low compression |
106-6028 |
106-6027 |
18°/38° |
40°/18° |
236° |
238° |
.472" |
.163"
|
.187" |
No |
Hydraulic |
| 585 |
74"–80" engines 8.5:1 - 9.5:1 CR 84" - 93" up to 8:1 - 9:1 CR |
33-5131 |
33-5109
|
20°/45° |
60°/20° |
245° |
260° |
.540" |
.172"
|
.166" |
Yes |
Hydraulic |
| 600 |
93"–103" engines 9:1 - 10:1 CR |
33-5132 |
33-5058 |
20°/55° |
60°/20° |
255° |
260° |
.554" |
.177" |
.170" |
Yes |
Hydraulic |
| 631 |
High RPM Cam for 93"–103" Engines 11:1+ CR |
33-5078 |
33-5080 |
34°/61° |
66°/29° |
275° |
275° |
.581" |
.359" |
.204" |
Yes |
Solid or Hydraulic |
| 640 |
93"–Up Engines 10:1 or Greater Compression
|
106-4639 |
33-5108 |
25°/60° |
65°/20° |
265° |
265° |
.590" |
.205" |
.192" |
Yes |
Hydraulic |
|
1Timing designation is function of zero lash @ .053" off base circle. Lifts based on 1.5:1 Rocker Ratio. 2Lifts at TDC are measured at the valve and are for reference only. Overlap valve lifts must be checked on assembled motor.
|
NOTES: In order to achieve stated timing specifications, these cams must be used in engines with 1984–'99 style tappets.
These cams should not be ordered as replacement parts for early S&S SH-Series engines, or for any shovelhead engine equipped with stock valve train. For replacement parts for these engines, select stock style cams and tappets.