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Harley-Davidson Sportster Cams

    The following cams are stock factory H-D for 1957-85 ironhead Sportsters.

H-D Stock Sportster

Cam Grind

Intake

Exhaust

Duration

Overlap

Lobe Center

Lobe Sep. Angle

Lobe Height
(45 or K lift)

Lift @ 1.5:1 Rockers

Name

Letter

Open BTDC

Close ABDC

Open BBDC

Close ATDC

Int.

Exh.

Int.

Exh.

Int.

Exh.

Int.

Exh.

1976-85

Q

10°

32°

35°

7°

222°

222°

  17°

101°

104°

102.5°

.267”

.267”

.400”

.400”

@.050”?

P

42°

42°

45°

40°

264°

265°

  82°

  90°

  92.5°

  91.25°

.267”

.267”

.400”

.400”

@.005”

82°

82°

85°

80°

344°

345°

162°

@.050”?

PB

37°

47°

52°

34°

264°

266°

  71°

  95°

  99°

  97°

.267”

.267”

.400”

.400”

@.005”

77°

87°

92°

74°

344°

346°

151°

Sifton
    Tom Sifton original cams have flat-sided gears with steep bevels. The lobes are stamped with the cam number 1-4, the same as H-D (indicating, in order from the left: rear exhaust, rear intake, front intake, front exhaust), plus one or two letters, characters or numbers. The gear is frequently stamped with the opening and closing points of that cam @ .053” lift, although some have other figures that I cannot reconcile which may have been the month and year of manufacture. Sifton cams are

now made by Tedd’s Cycle, and look like stock cams as to gears etc. I can’t find any data re the Sifton name (Barracuda) vs. letter (C) vs. grind #, which were listed in the catalog.
    Mixing one intake pair grind (#2 & 3) with another exhaust pair (#1 & 4) was common, and referred to using both characters: “C-” is a “C” intake pair with a “-” exhaust pair, etc. Click the picture for a larger view.
    Big Sportster cams are characterized by broad but low lobes (.280” to .350”) because the 1.5:1 rocker arm ratio increases the lift at the valve by 50%. Compare this with KR cams which have very tall lobes (.375” to .440”) but no rocker arms.
    A good indicator of where peak power is found is not lift, but intake valve closing point - notice these are sorted in this ascending order (hottest at bottom).
    All cam positions and durations appear very conservative, but are actually quite hot since the figures are given @ .053” lift. The nominal or “paper” duration is probably at least another 40°. To get a more realistic picture for comparison with other cams add 20° to any opening or closing value, or 40° to any duration.
    The Barracuda cam (marked “C”) is very hot, upper end power only, big motor with high compression, needs special springs.
    The Titan cam or “minus-minus” (marked “-”) is the old dragster cam despite low lift. “Minus-minus” refers to intake and exhaust matching.
    Other marking were “H”, “+” etc.

    Here’s a set* graciously provided by “fantomen”, which appears to be +H intakes and H exhausts. The smaller journals are for R6 ball bearings. Click each image for a larger view.

    The row identified as “45/K” shows these same cams with the intake cam pair advanced 5° for better compression in a flathead engine, while the lift remains the lobe height with no rocker arms. Lift shows actual measurements, which may have some wear.

Sifton Sportster Cams

Cam Grind

Intake

Exhaust

Duration

Overlap

Lobe Center

Lobe Sep. Angle

Lobe Height
(45 or K lift)

Lift @ 1.5:1 Rockers

Name

Letter

Open BTDC

Close ABDC

Open BBDC

Close ATDC

Int.

Exh.

Int.

Exh.

Int.

Exh.

Int.

Exh.

Stingray

28°

42°

50°

20°

250°

250°

48°

  97°

105°

101.0°

.320”

.320”

.480”

.480”

Evader

28°

44°

50°

22°

252°

252°

50°

  98°

104°

101.0°

.343”

.343”

.515”

.515”

Manta

30°

48°

50°

28°

258°

258°

58°

  99°

101°

100.0°

.360”

.360”

.540”

.540”

*

+H/H

33°

50°

42°

20°

263°

242°

53°

  98.5°

101°

  99.75°

.289”

.287”

.433”

.430”

45/K

+H/H

38°

45°

42°

20°

263°

242°

58°

  93.5°

101°

  97.25°

.289”

.287”

.289”

.287”

Challenger

30°

55°

57°

31°

265°

268°

61°

102.5°

103°

102.75°

.293”

.293”

.440”

.480”

Titan

-

33°

55°

52°

25°

268°

257°

58°

101°

104.5°

102.75°

.291”

.291”

.436”

.436”

Barracuda

C

32°

56°

57°

31°

268°

268°

63°

102°

103°

102.5°

.320”

.320”

.480”

.480”

Pro Stock

36°

58°

58°

34°

274°

272°

70°

101°

102°

101.5°

.370”

.370”

.555”

.555”

    The following cams are listed for 1957-85 ironhead Sportster.

Andrews Products Sportster Cams

Cam

Dur.
@

Intake

Exhaust

Duration

Overlap

Lobe Center

Lobe Sep. Angle

Lobe Height
(45 or K lift)

Lift @ 1.5:1 Rockers

Letter

Open BTDC

Close ABDC

Open BBDC

Close ATDC

Int.

Exh.

Int.

Exh.

Int.

Exh.

Int.

Exh.

PB+

.053”

34°

40°

43°

31°

254°

254°

65°

   93°

   96°

94.5°

.273"

.273"

.410"

.410"

.020”

56°

62°

65°

53°

298°

298°

109°

Y

.053”

35°

47°

53°

29°

262°

262°

64°

   96°

 102°

 99°

.283"

.283"

.425"

.425"

.020”

59°

71°

77°

53°

310°

310°

112°

R5

.053”

33°

41°

43°

31°

254°

254°

64°

   94°

   96°

 95°

.297"

.297"

.445"

.445"

.020”

61°

69°

71°

59°

310°

310°

120°

X

.053”

35°

55°

57°

33°

270°

270°

68°

 100°

 102°

  101°

.300"

.300"

.450"

.450"

.020”

57°

77°

79°

55°

314°

314°

112°

V9

.053”

32°

52°

52°

32°

264°

264°

64°

 100°

 100°

  100°

.327"

.327"

.490"

.490"

.020”

   55.5°

   75.5°

   75.5°

   55.5°

311°

311°

111°

What’s Related?

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and pinion gears