Here are some comments and data to assist in identifying cams.
    The cams used in all 1936-69 OHV big twin motors drive all 4 cam lobes on a single shaft. The sequence of gears (oil pump drive, ignition drive and breather) is unique to this series.
    The cams used in the later 4-cam side-valve motors, such as the 1937-48 U-Series (U, UL, UH, ULH, UMG, UA, etc.), and 45 1937-73 (G, W, WL, WLA, WLC, WLD, etc.) are completely different, but are similar in appearance to each other, and to both older 1932-36 side-valve (R, V, etc.) and newer 1952-69 K & Sportster cams. Please note that, in additional to other factors, all 1937-48 U-Series & 1930-36 V-Series cams have an inner gear row with 32 teeth; all 1937-73 45 W-Series & 1932-36 R-Series cams have an inner gear row with 28 teeth.

E & F-Series Cams 1936-69

Component

Gear

Lobe

Notes

Pinion

21

6 flutes; asymmetrical

Oil pump drive

25

right-hand spiral

Generator idler

51

OHV only

Generator drive

14

Cam

42

.200”-.365”

lift varies with state of tune and rocker ratio

V-Series Cams 1930-36

Component

Cylinder

Valve

Inner gear

Outer gear

Lobe

Notes; Outer journal OD

Pinion

N/A

N/A

20

keyway

Generator idler

42

1930-48 all BT SV

Generator drive

14

plain

Cam #1

Rear

Exhaust

32

V, VC: .344" VL, VLD: .375”inner jls. .610”

ignition drive, very long shaft

Cam #2

Intake

40

.610”

Cam #3

Front

Cam #4

Exhaust

42

1930-33: 1.06” shaft with oil pump spiral drive

1934-36: .89” shaft with oil pump spiral drive

U-Series Cams 1937-48

Component

Cylinder

Valve

Inner gear

Outer gear

Lobe

Notes; Outer journal OD

Pinion

N/A

N/A

20

6 flutes; asymmetrical

Return pump drive

10

left-hand spiral, with timing mark

Generator idler

42

1930-48 all BT SV

Generator drive

14

oil slinger

Cam #1

Rear

Exhaust

32

.375"inner jls.
11/16"

2 tangs for oil pump drive

Cam #2

Intake

40

spiral gear for ignition drive

Cam #3

Front

11/16”

Cam #4

Exhaust

42

Common U-Series Cam ID Errors

Appears to be U-Series (32 teeth); but:

Actual ID

Small (.610”) journals

1930-36 VL

28 tooth gear

1932-73 45; K; 1957-69 Sportster

Pinion gear 4 spline

1937-* 45; K; Sportster

Pinion gear 21 teeth

1936-53 OHV

Return pump drive right hand spiral

1936-53 OHV

Generator idler 51 teeth

OHV

Idler 42 teeth with spiral ignition drive

1936-69 OHV

45 R-Series Cams 1932-36

Component

Cylinder

Valve

Inner gear

Outer gear

Lobe

Notes; Outer journal OD

Pinion

N/A

N/A

18

keyway

Generator idler

46

1932-73 all 45 SV

Generator drive

14

plain

Cam #1

Rear

Exhaust

28

.312"inner jls. .610”

ignition drive, very long shaft

Cam #2

Intake

36

.610”

Cam #3

Front

Cam #4

Exhaust

36

1932-33: 1.06" shaft with oil pump spiral drive

1934-36: .89" shaft with oil pump spiral drive

45 Cams 1937-73

Component

Cylinder

Valve

Inner gear

Outer gear

Lobe

Notes; Outer journal OD

Pinion

N/A

N/A

18

4 flutes; asymmetrical

Return pump drive

10

left-hand spiral

Generator idler

46

1932-73 all 45 SV

Generator drive

14

oil slinger

Cam #1

Rear

Exhaust

28

.312”inner jls. 11/16”

2 tangs for oil pump drive

Cam #2

Intake

36

spiral gear for ignition drive

Cam #3

Front

11/16”

Cam #4

Exhaust

36

WR Cams 1941-52

Component

Cylinder

Valve

Inner gear

Outer gear

Lobe

Notes; Outer journal OD

Pinion

N/A

N/A

18

4 flutes; asymmetrical

Return pump drive

10

left-hand spiral

Magneto idler

36

front-mount

Magneto drive

Cam #1

Rear

Exhaust

28

.344” square
pointed lobeinner jls. 3/8”

2 tangs for oil pump drive

Cam #2

Intake

36

1941-47: 3/8”
1948-52: spiral gear for ignition drive

Cam #3

Front

Intake

3/8”

Cam #4

Exhaust

36

K & KH Cams 1952-56

Component

Cylinder

Valve

Inner gear

Outer gear

Lobe

Notes; Outer journal OD

Pinion

N/A

N/A

18

4 flutes; asymmetrical

Oil pump drive

10

left-hand spiral

Generator idler

46

Generator drive

14

Cam #1

Rear

Exhaust

28

1952-56 K, KH:
.344” pointed 1953-56 KK, KHK:
.375” “figure 8” lobeinner jls. 11/16”

11/16”

Cam #2

Intake

36

spiral gear for ignition drive

Cam #3

Front

Intake

11/16”

Cam #4

Exhaust

36

KR Cams 1953-69

Component

Cylinder

Valve

Inner gear

Outer gear

Lobe

Notes; Outer journal OD

Pinion

N/A

N/A

18

4 flutes; asymmetrical

Oil pump drive

5

shallow left-hand spiral

Magneto idler

36

Magneto drive

36

Cam #1

Rear

Exhaust

28

.375-.440”
“figure 8” lobeinner jls. 3/8”

3/8”

Cam #2

Intake

36

Cam #3

Front

Cam #4

Exhaust

36

XL Cams 1957-69

Component

Cylinder

Valve

Inner gear

Outer gear

Lobe

Notes; Outer journal OD

Pinion

N/A

N/A

18

4 flutes; asymmetrical

Oil pump drive

10

left-hand spiral

Generator idler

46

Generator drive

14

Cam #1

Rear

Exhaust

28

.267” round, broad lobeinner jls. 11/16”

11/16”

Cam #2

Intake

36

spiral gear for ignition drive

Cam #3

Front

11/16”

Cam #4

Exhaust

36

Common 45 Cam ID Errors

Appears to be 45 (28 teeth); but:

Actual ID

Small (.610”) journals

1932-36 RL

Small (.610”) journals + 32 tooth gear

1930-36 VL

Lobes pointed; .344” height; .375” jls.

1941-52 WR

Lobes beveled; .344” height

1952-56 K; KH

Lobes beveled, concave flanks; .375” height

1953-56 KK; KHK

Lobes beveled, concave flanks; .375+” height; .375” jls.

1953-69 KR

Lobe height .267” (+/-)

1957-69 Sportster

Lobe height .267” (+/-); .375” jls.

1957-* XLR

32 tooth gear

1937-48 UL

No ignition spiral on #2 cam

1941-47 WR; KR; 1970-* XL

Pinion gear 6 spline

1937-48 UL

Return pump drive 6 spline

1937-48 UL

Return pump drive 4 spline, 5 tooth

1954-* KR 1/4-speed pump

Generator idler 51 teeth

1936-69 OHV

What’s Related?

Sportster cams

Andrews cams
for the 45

KR cam tables

Side-valve cams
by Web-Cam

Re-timing cams
and pinion gears